move files again

93 files changed, 8761 insertions, 0 deletions

diff --git a/include/py/__init__.py b/include/py/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/include/py/__init__.py
diff --git a/include/py/homekit/__init__.py b/include/py/homekit/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/include/py/homekit/__init__.py
diff --git a/include/py/homekit/api/__init__.py b/include/py/homekit/api/__init__.py
new file mode 100644
index 0000000..d641f62
--- /dev/null
+++ b/include/py/homekit/api/__init__.py
@@ -0,0 +1,19 @@
+import importlib
+
+__all__ = [
+    # web_api_client.py
+    'WebApiClient',
+    'RequestParams',
+
+    # config.py
+    'WebApiConfig'
+]
+
+
+def __getattr__(name):
+    if name in __all__:
+        file = 'config' if name == 'WebApiConfig' else 'web_api_client'
+        module = importlib.import_module(f'.{file}', __name__)
+        return getattr(module, name)
+
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
diff --git a/include/py/homekit/api/__init__.pyi b/include/py/homekit/api/__init__.pyi
new file mode 100644
index 0000000..5b98161
--- /dev/null
+++ b/include/py/homekit/api/__init__.pyi
@@ -0,0 +1,5 @@
+from .web_api_client import (
+    RequestParams as RequestParams,
+    WebApiClient as WebApiClient
+)
+from .config import WebApiConfig as WebApiConfig
diff --git a/include/py/homekit/api/config.py b/include/py/homekit/api/config.py
new file mode 100644
index 0000000..00c1097
--- /dev/null
+++ b/include/py/homekit/api/config.py
@@ -0,0 +1,15 @@
+from ..config import ConfigUnit
+from typing import Optional, Union
+
+
+class WebApiConfig(ConfigUnit):
+    NAME = 'web_api'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'listen_addr': cls._addr_schema(required=True),
+            'host': cls._addr_schema(required=True),
+            'token': dict(type='string', required=True),
+            'recordings_dir': dict(type='string', required=True)
+        }
\ No newline at end of file
diff --git a/include/py/homekit/api/errors/__init__.py b/include/py/homekit/api/errors/__init__.py
new file mode 100644
index 0000000..efb06aa
--- /dev/null
+++ b/include/py/homekit/api/errors/__init__.py
@@ -0,0 +1 @@
+from .api_response_error import ApiResponseError
diff --git a/include/py/homekit/api/errors/api_response_error.py b/include/py/homekit/api/errors/api_response_error.py
new file mode 100644
index 0000000..85d788b
--- /dev/null
+++ b/include/py/homekit/api/errors/api_response_error.py
@@ -0,0 +1,28 @@
+from typing import Optional, List
+
+
+class ApiResponseError(Exception):
+    def __init__(self,
+                 status_code: int,
+                 error_type: str,
+                 error_message: str,
+                 error_stacktrace: Optional[List[str]] = None):
+        super().__init__()
+        self.status_code = status_code
+        self.error_message = error_message
+        self.error_type = error_type
+        self.error_stacktrace = error_stacktrace
+
+    def __str__(self):
+        def st_formatter(line: str):
+            return f'Remote| {line}'
+
+        s = f'{self.error_type}: {self.error_message} (HTTP {self.status_code})'
+        if self.error_stacktrace is not None:
+            st = []
+            for st_line in self.error_stacktrace:
+                st.append('\n'.join(st_formatter(st_subline) for st_subline in st_line.split('\n')))
+            s += '\nRemote stacktrace:\n'
+            s += '\n'.join(st)
+
+        return s
diff --git a/include/py/homekit/api/types/__init__.py b/include/py/homekit/api/types/__init__.py
new file mode 100644
index 0000000..9f27ff6
--- /dev/null
+++ b/include/py/homekit/api/types/__init__.py
@@ -0,0 +1,6 @@
+from .types import (
+    BotType,
+    TemperatureSensorDataType,
+    TemperatureSensorLocation,
+    SoundSensorLocation
+)
diff --git a/include/py/homekit/api/types/types.py b/include/py/homekit/api/types/types.py
new file mode 100644
index 0000000..981e798
--- /dev/null
+++ b/include/py/homekit/api/types/types.py
@@ -0,0 +1,33 @@
+from enum import Enum, auto
+
+
+class BotType(Enum):
+    INVERTER = auto()
+    PUMP = auto()
+    SENSORS = auto()
+    ADMIN = auto()
+    SOUND = auto()
+    POLARIS_KETTLE = auto()
+    PUMP_MQTT = auto()
+    RELAY_MQTT = auto()
+
+
+class TemperatureSensorLocation(Enum):
+    BIG_HOUSE_1 = auto()
+    BIG_HOUSE_2 = auto()
+    BIG_HOUSE_ROOM = auto()
+    STREET = auto()
+    DIANA = auto()
+    SPB1 = auto()
+
+
+class TemperatureSensorDataType(Enum):
+    TEMPERATURE = auto()
+    RELATIVE_HUMIDITY = auto()
+
+
+class SoundSensorLocation(Enum):
+    DIANA = auto()
+    BIG_HOUSE = auto()
+    SPB1 = auto()
+
diff --git a/include/py/homekit/api/web_api_client.py b/include/py/homekit/api/web_api_client.py
new file mode 100644
index 0000000..15c1915
--- /dev/null
+++ b/include/py/homekit/api/web_api_client.py
@@ -0,0 +1,227 @@
+import requests
+import json
+import threading
+import logging
+
+from collections import namedtuple
+from datetime import datetime
+from enum import Enum, auto
+from typing import Optional, Callable, Union, List, Tuple, Dict
+from requests.auth import HTTPBasicAuth
+
+from .config import WebApiConfig
+from .errors import ApiResponseError
+from .types import *
+from ..config import config
+from ..util import stringify
+from ..media import RecordFile, MediaNodeClient
+
+_logger = logging.getLogger(__name__)
+_config = WebApiConfig()
+
+
+RequestParams = namedtuple('RequestParams', 'params, files, method')
+
+
+class HTTPMethod(Enum):
+    GET = auto()
+    POST = auto()
+
+
+class WebApiClient:
+    token: str
+    timeout: Union[float, Tuple[float, float]]
+    basic_auth: Optional[HTTPBasicAuth]
+    do_async: bool
+    async_error_handler: Optional[Callable]
+    async_success_handler: Optional[Callable]
+
+    def __init__(self, timeout: Union[float, Tuple[float, float]] = 5):
+        self.token = config['token']
+        self.timeout = timeout
+        self.basic_auth = None
+        self.do_async = False
+        self.async_error_handler = None
+        self.async_success_handler = None
+
+        # if 'basic_auth' in config['api']:
+        #     ba = config['api']['basic_auth']
+        #     col = ba.index(':')
+        #
+        #     user = ba[:col]
+        #     pw = ba[col+1:]
+        #
+        #     _logger.debug(f'enabling basic auth: {user}:{pw}')
+        #     self.basic_auth = HTTPBasicAuth(user, pw)
+
+    # api methods
+    # -----------
+
+    def log_bot_request(self,
+                        bot: BotType,
+                        user_id: int,
+                        message: str):
+        return self._post('log/bot_request/', {
+            'bot': bot.value,
+            'user_id': str(user_id),
+            'message': message
+        })
+
+    def log_openwrt(self,
+                    lines: List[Tuple[int, str]],
+                    access_point: int):
+        return self._post('log/openwrt/', {
+            'logs': stringify(lines),
+            'ap': access_point
+        })
+
+    def get_sensors_data(self,
+                         sensor: TemperatureSensorLocation,
+                         hours: int):
+        data = self._get('sensors/data/', {
+            'sensor': sensor.value,
+            'hours': hours
+        })
+        return [(datetime.fromtimestamp(date), temp, hum) for date, temp, hum in data]
+
+    def add_sound_sensor_hits(self,
+                              hits: List[Tuple[str, int]]):
+        return self._post('sound_sensors/hits/', {
+            'hits': stringify(hits)
+        })
+
+    def get_sound_sensor_hits(self,
+                              location: SoundSensorLocation,
+                              after: datetime) -> List[dict]:
+        return self._process_sound_sensor_hits_data(self._get('sound_sensors/hits/', {
+            'after': int(after.timestamp()),
+            'location': location.value
+        }))
+
+    def get_last_sound_sensor_hits(self, location: SoundSensorLocation, last: int):
+        return self._process_sound_sensor_hits_data(self._get('sound_sensors/hits/', {
+            'last': last,
+            'location': location.value
+        }))
+
+    def recordings_list(self, extended=False, as_objects=False) -> Union[List[str], List[dict], List[RecordFile]]:
+        files = self._get('recordings/list/', {'extended': int(extended)})['data']
+        if as_objects:
+            return MediaNodeClient.record_list_from_serialized(files)
+        return files
+
+    def inverter_get_consumed_energy(self, s_from: str, s_to: str):
+        return self._get('inverter/consumed_energy/', {
+            'from': s_from,
+            'to': s_to
+        })
+
+    def inverter_get_grid_consumed_energy(self, s_from: str, s_to: str):
+        return self._get('inverter/grid_consumed_energy/', {
+            'from': s_from,
+            'to': s_to
+        })
+
+    @staticmethod
+    def _process_sound_sensor_hits_data(data: List[dict]) -> List[dict]:
+        for item in data:
+            item['time'] = datetime.fromtimestamp(item['time'])
+        return data
+
+    # internal methods
+    # ----------------
+
+    def _get(self, *args, **kwargs):
+        return self._call(method=HTTPMethod.GET, *args, **kwargs)
+
+    def _post(self, *args, **kwargs):
+        return self._call(method=HTTPMethod.POST, *args, **kwargs)
+
+    def _call(self,
+              name: str,
+              params: dict,
+              method: HTTPMethod,
+              files: Optional[Dict[str, str]] = None):
+        if not self.do_async:
+            return self._make_request(name, params, method, files)
+        else:
+            t = threading.Thread(target=self._make_request_in_thread, args=(name, params, method, files))
+            t.start()
+            return None
+
+    def _make_request(self,
+                      name: str,
+                      params: dict,
+                      method: HTTPMethod = HTTPMethod.GET,
+                      files: Optional[Dict[str, str]] = None) -> Optional[any]:
+        domain = config['host']
+        kwargs = {}
+
+        if self.basic_auth is not None:
+            kwargs['auth'] = self.basic_auth
+
+        if method == HTTPMethod.GET:
+            if files:
+                raise RuntimeError('can\'t upload files using GET, please use me properly')
+            kwargs['params'] = params
+            f = requests.get
+        else:
+            kwargs['data'] = params
+            f = requests.post
+
+        fd = {}
+        if files:
+            for fname, fpath in files.items():
+                fd[fname] = open(fpath, 'rb')
+            kwargs['files'] = fd
+
+        try:
+            r = f(f'https://{domain}/{name}',
+                  headers={'X-Token': self.token},
+                  timeout=self.timeout,
+                  **kwargs)
+
+            if not r.headers['content-type'].startswith('application/json'):
+                raise ApiResponseError(r.status_code, 'TypeError', 'content-type is not application/json')
+
+            data = json.loads(r.text)
+            if r.status_code != 200:
+                raise ApiResponseError(r.status_code,
+                                       data['error'],
+                                       data['message'],
+                                       data['stacktrace'] if 'stacktrace' in data['error'] else None)
+
+            return data['response'] if 'response' in data else True
+        finally:
+            for fname, f in fd.items():
+                # logger.debug(f'closing file {fname} (fd={f})')
+                try:
+                    f.close()
+                except Exception as exc:
+                    _logger.exception(exc)
+                    pass
+
+    def _make_request_in_thread(self, name, params, method, files):
+        try:
+            result = self._make_request(name, params, method, files)
+            self._report_async_success(result, name, RequestParams(params=params, method=method, files=files))
+        except Exception as e:
+            _logger.exception(e)
+            self._report_async_error(e, name, RequestParams(params=params, method=method, files=files))
+
+    def enable_async(self,
+                     success_handler: Optional[Callable] = None,
+                     error_handler: Optional[Callable] = None):
+        self.do_async = True
+        if error_handler:
+            self.async_error_handler = error_handler
+        if success_handler:
+            self.async_success_handler = success_handler
+
+    def _report_async_error(self, *args):
+        if self.async_error_handler:
+            self.async_error_handler(*args)
+
+    def _report_async_success(self, *args):
+        if self.async_success_handler:
+            self.async_success_handler(*args)
\ No newline at end of file
diff --git a/include/py/homekit/audio/__init__.py b/include/py/homekit/audio/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/include/py/homekit/audio/__init__.py
diff --git a/include/py/homekit/audio/amixer.py b/include/py/homekit/audio/amixer.py
new file mode 100644
index 0000000..5133c97
--- /dev/null
+++ b/include/py/homekit/audio/amixer.py
@@ -0,0 +1,91 @@
+import subprocess
+
+from ..config import app_config as config
+from threading import Lock
+from typing import Union, List
+
+
+_lock = Lock()
+_default_step = 5
+
+
+def has_control(s: str) -> bool:
+    for control in config['amixer']['controls']:
+        if control['name'] == s:
+            return True
+    return False
+
+
+def get_caps(s: str) -> List[str]:
+    for control in config['amixer']['controls']:
+        if control['name'] == s:
+            return control['caps']
+    raise KeyError(f'control {s} not found')
+
+
+def get_all() -> list:
+    controls = []
+    for control in config['amixer']['controls']:
+        controls.append({
+            'name': control['name'],
+            'info': get(control['name']),
+            'caps': control['caps']
+        })
+    return controls
+
+
+def get(control: str):
+    return call('get', control)
+
+
+def mute(control):
+    return call('set', control, 'mute')
+
+
+def unmute(control):
+    return call('set', control, 'unmute')
+
+
+def cap(control):
+    return call('set', control, 'cap')
+
+
+def nocap(control):
+    return call('set', control, 'nocap')
+
+
+def _get_default_step() -> int:
+    if 'step' in config['amixer']:
+        return int(config['amixer']['step'])
+
+    return _default_step
+
+
+def incr(control, step=None):
+    if step is None:
+        step = _get_default_step()
+    return call('set', control, f'{step}%+')
+
+
+def decr(control, step=None):
+    if step is None:
+        step = _get_default_step()
+    return call('set', control, f'{step}%-')
+
+
+def call(*args, return_code=False) -> Union[int, str]:
+    with _lock:
+        result = subprocess.run([config['amixer']['bin'], *args],
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+        if return_code:
+            return result.returncode
+
+        if result.returncode != 0:
+            raise AmixerError(result.stderr.decode().strip())
+
+        return result.stdout.decode().strip()
+
+
+class AmixerError(OSError):
+    pass
diff --git a/include/py/homekit/camera/__init__.py b/include/py/homekit/camera/__init__.py
new file mode 100644
index 0000000..626930b
--- /dev/null
+++ b/include/py/homekit/camera/__init__.py
@@ -0,0 +1 @@
+from .types import CameraType
\ No newline at end of file
diff --git a/include/py/homekit/camera/esp32.py b/include/py/homekit/camera/esp32.py
new file mode 100644
index 0000000..fe6de0e
--- /dev/null
+++ b/include/py/homekit/camera/esp32.py
@@ -0,0 +1,226 @@
+import logging
+import requests
+import json
+import asyncio
+import aioshutil
+
+from io import BytesIO
+from functools import partial
+from typing import Union, Optional
+from enum import Enum
+from ..api.errors import ApiResponseError
+from ..util import Addr
+
+
+class FrameSize(Enum):
+    UXGA_1600x1200 = 13
+    SXGA_1280x1024 = 12
+    HD_1280x720 = 11
+    XGA_1024x768 = 10
+    SVGA_800x600 = 9
+    VGA_640x480 = 8
+    HVGA_480x320 = 7
+    CIF_400x296 = 6
+    QVGA_320x240 = 5
+    N_240x240 = 4
+    HQVGA_240x176 = 3
+    QCIF_176x144 = 2
+    QQVGA_160x120 = 1
+    N_96x96 = 0
+
+
+class WBMode(Enum):
+    AUTO = 0
+    SUNNY = 1
+    CLOUDY = 2
+    OFFICE = 3
+    HOME = 4
+
+
+def _assert_bounds(n: int, min: int, max: int):
+    if not min <= n <= max:
+        raise ValueError(f'value must be between {min} and {max}')
+
+
+class WebClient:
+    def __init__(self,
+                 addr: Addr):
+        self.endpoint = f'http://{addr[0]}:{addr[1]}'
+        self.logger = logging.getLogger(self.__class__.__name__)
+        self.delay = 0
+        self.isfirstrequest = True
+
+    async def syncsettings(self, settings) -> bool:
+        status = await self.getstatus()
+        self.logger.debug(f'syncsettings: status={status}')
+
+        changed_anything = False
+
+        for name, value in settings.items():
+            server_name = name
+            if name == 'aec_dsp':
+                server_name = 'aec2'
+
+            if server_name not in status:
+                # legacy compatibility
+                if server_name != 'vflip':
+                    self.logger.warning(f'syncsettings: field `{server_name}` not found in camera status')
+                    continue
+
+            try:
+                # server returns 0 or 1 for bool values
+                if type(value) is bool:
+                    value = int(value)
+
+                if status[server_name] == value:
+                    continue
+            except KeyError as exc:
+                if name != 'vflip':
+                    self.logger.error(exc)
+
+            try:
+                # fix for cases like when field is called raw_gma, but method is setrawgma()
+                name = name.replace('_', '')
+
+                func = getattr(self, f'set{name}')
+                self.logger.debug(f'syncsettings: calling set{name}({value})')
+
+                await func(value)
+
+                changed_anything = True
+            except AttributeError as exc:
+                self.logger.exception(exc)
+                self.logger.error(f'syncsettings: method set{name}() not found')
+
+        return changed_anything
+
+    def setdelay(self, delay: int):
+        self.delay = delay
+
+    async def capture(self, output: Optional[str] = None) -> Union[BytesIO, bool]:
+        kw = {}
+        if output:
+            kw['save_to'] = output
+        else:
+            kw['as_bytes'] = True
+        return await self._call('capture', **kw)
+
+    async def getstatus(self):
+        return json.loads(await self._call('status'))
+
+    async def setflash(self, enable: bool):
+        await self._control('flash', int(enable))
+
+    async def setframesize(self, fs: Union[int, FrameSize]):
+        if type(fs) is int:
+            fs = FrameSize(fs)
+        await self._control('framesize', fs.value)
+
+    async def sethmirror(self, enable: bool):
+        await self._control('hmirror', int(enable))
+
+    async def setvflip(self, enable: bool):
+        await self._control('vflip', int(enable))
+
+    async def setawb(self, enable: bool):
+        await self._control('awb', int(enable))
+
+    async def setawbgain(self, enable: bool):
+        await self._control('awb_gain', int(enable))
+
+    async def setwbmode(self, mode: WBMode):
+        await self._control('wb_mode', mode.value)
+
+    async def setaecsensor(self, enable: bool):
+        await self._control('aec', int(enable))
+
+    async def setaecdsp(self, enable: bool):
+        await self._control('aec2', int(enable))
+
+    async def setagc(self, enable: bool):
+        await self._control('agc', int(enable))
+
+    async def setagcgain(self, gain: int):
+        _assert_bounds(gain, 1, 31)
+        await self._control('agc_gain', gain)
+
+    async def setgainceiling(self, gainceiling: int):
+        _assert_bounds(gainceiling, 2, 128)
+        await self._control('gainceiling', gainceiling)
+
+    async def setbpc(self, enable: bool):
+        await self._control('bpc', int(enable))
+
+    async def setwpc(self, enable: bool):
+        await self._control('wpc', int(enable))
+
+    async def setrawgma(self, enable: bool):
+        await self._control('raw_gma', int(enable))
+
+    async def setlenscorrection(self, enable: bool):
+        await self._control('lenc', int(enable))
+
+    async def setdcw(self, enable: bool):
+        await self._control('dcw', int(enable))
+
+    async def setcolorbar(self, enable: bool):
+        await self._control('colorbar', int(enable))
+
+    async def setquality(self, q: int):
+        _assert_bounds(q, 4, 63)
+        await self._control('quality', q)
+
+    async def setbrightness(self, brightness: int):
+        _assert_bounds(brightness, -2, -2)
+        await self._control('brightness', brightness)
+
+    async def setcontrast(self, contrast: int):
+        _assert_bounds(contrast, -2, 2)
+        await self._control('contrast', contrast)
+
+    async def setsaturation(self, saturation: int):
+        _assert_bounds(saturation, -2, 2)
+        await self._control('saturation', saturation)
+
+    async def _control(self, var: str, value: Union[int, str]):
+        return await self._call('control', params={'var': var, 'val': value})
+
+    async def _call(self,
+                    method: str,
+                    params: Optional[dict] = None,
+                    save_to: Optional[str] = None,
+                    as_bytes=False) -> Union[str, bool, BytesIO]:
+        loop = asyncio.get_event_loop()
+
+        if not self.isfirstrequest and self.delay > 0:
+            sleeptime = self.delay / 1000
+            self.logger.debug(f'sleeping for {sleeptime}')
+
+            await asyncio.sleep(sleeptime)
+
+        self.isfirstrequest = False
+
+        url = f'{self.endpoint}/{method}'
+        self.logger.debug(f'calling {url}, params: {params}')
+
+        kwargs = {}
+        if params:
+            kwargs['params'] = params
+        if save_to:
+            kwargs['stream'] = True
+
+        r = await loop.run_in_executor(None,
+                                       partial(requests.get, url, **kwargs))
+        if r.status_code != 200:
+            raise ApiResponseError(status_code=r.status_code)
+
+        if as_bytes:
+            return BytesIO(r.content)
+
+        if save_to:
+            r.raise_for_status()
+            with open(save_to, 'wb') as f:
+                await aioshutil.copyfileobj(r.raw, f)
+            return True
+
+        return r.text
diff --git a/include/py/homekit/camera/types.py b/include/py/homekit/camera/types.py
new file mode 100644
index 0000000..de59022
--- /dev/null
+++ b/include/py/homekit/camera/types.py
@@ -0,0 +1,5 @@
+from enum import Enum
+
+
+class CameraType(Enum):
+    ESP32 = 'esp32'
diff --git a/include/py/homekit/camera/util.py b/include/py/homekit/camera/util.py
new file mode 100644
index 0000000..97f35aa
--- /dev/null
+++ b/include/py/homekit/camera/util.py
@@ -0,0 +1,107 @@
+import asyncio
+import os.path
+import logging
+import psutil
+
+from typing import List, Tuple
+from ..util import chunks
+from ..config import config
+
+_logger = logging.getLogger(__name__)
+_temporary_fixing = '.temporary_fixing.mp4'
+
+
+def _get_ffmpeg_path() -> str:
+    return 'ffmpeg' if 'ffmpeg' not in config else config['ffmpeg']['path']
+
+
+def time2seconds(time: str) -> int:
+    time, frac = time.split('.')
+    frac = int(frac)
+
+    h, m, s = [int(i) for i in time.split(':')]
+
+    return round(s + m*60 + h*3600 + frac/1000)
+
+
+async def ffmpeg_recreate(filename: str):
+    filedir = os.path.dirname(filename)
+    tempname = os.path.join(filedir, _temporary_fixing)
+    mtime = os.path.getmtime(filename)
+
+    args = [_get_ffmpeg_path(), '-nostats', '-loglevel', 'error', '-i', filename, '-c', 'copy', '-y', tempname]
+    proc = await asyncio.create_subprocess_exec(*args,
+                                                stdout=asyncio.subprocess.PIPE,
+                                                stderr=asyncio.subprocess.PIPE)
+    stdout, stderr = await proc.communicate()
+    if proc.returncode != 0:
+        _logger.error(f'fix_timestamps({filename}): ffmpeg returned {proc.returncode}, stderr: {stderr.decode().strip()}')
+
+    if os.path.isfile(tempname):
+        os.unlink(filename)
+        os.rename(tempname, filename)
+        os.utime(filename, (mtime, mtime))
+        _logger.info(f'fix_timestamps({filename}): OK')
+    else:
+        _logger.error(f'fix_timestamps({filename}): temp file \'{tempname}\' does not exists, fix failed')
+
+
+async def ffmpeg_cut(input: str,
+                     output: str,
+                     start_pos: int,
+                     duration: int):
+    args = [_get_ffmpeg_path(), '-nostats', '-loglevel', 'error', '-i', input,
+            '-ss', str(start_pos), '-t', str(duration),
+            '-c', 'copy', '-y', output]
+    proc = await asyncio.create_subprocess_exec(*args,
+                                                stdout=asyncio.subprocess.PIPE,
+                                                stderr=asyncio.subprocess.PIPE)
+    stdout, stderr = await proc.communicate()
+    if proc.returncode != 0:
+        _logger.error(f'ffmpeg_cut({input}, start_pos={start_pos}, duration={duration}): ffmpeg returned {proc.returncode}, stderr: {stderr.decode().strip()}')
+    else:
+        _logger.info(f'ffmpeg_cut({input}): OK')
+
+
+def dvr_scan_timecodes(timecodes: str) -> List[Tuple[int, int]]:
+    tc_backup = timecodes
+
+    timecodes = timecodes.split(',')
+    if len(timecodes) % 2 != 0:
+        raise DVRScanInvalidTimecodes(f'invalid number of timecodes. input: {tc_backup}')
+
+    timecodes = list(map(time2seconds, timecodes))
+    timecodes = list(chunks(timecodes, 2))
+
+    # sort out invalid fragments (dvr-scan returns them sometimes, idk why...)
+    timecodes = list(filter(lambda f: f[0] < f[1], timecodes))
+    if not timecodes:
+        raise DVRScanInvalidTimecodes(f'no valid timecodes. input: {tc_backup}')
+
+    # https://stackoverflow.com/a/43600953
+    timecodes.sort(key=lambda interval: interval[0])
+    merged = [timecodes[0]]
+    for current in timecodes:
+        previous = merged[-1]
+        if current[0] <= previous[1]:
+            previous[1] = max(previous[1], current[1])
+        else:
+            merged.append(current)
+
+    return merged
+
+
+class DVRScanInvalidTimecodes(Exception):
+    pass
+
+
+def has_handle(fpath):
+    for proc in psutil.process_iter():
+        try:
+            for item in proc.open_files():
+                if fpath == item.path:
+                    return True
+        except Exception:
+            pass
+
+    return False
\ No newline at end of file
diff --git a/include/py/homekit/config/__init__.py b/include/py/homekit/config/__init__.py
new file mode 100644
index 0000000..2fa5214
--- /dev/null
+++ b/include/py/homekit/config/__init__.py
@@ -0,0 +1,13 @@
+from .config import (
+    Config,
+    ConfigUnit,
+    AppConfigUnit,
+    Translation,
+    config,
+    is_development_mode,
+    setup_logging
+)
+from ._configs import (
+    LinuxBoardsConfig,
+    ServicesListConfig
+)
\ No newline at end of file
diff --git a/include/py/homekit/config/_configs.py b/include/py/homekit/config/_configs.py
new file mode 100644
index 0000000..1628cba
--- /dev/null
+++ b/include/py/homekit/config/_configs.py
@@ -0,0 +1,55 @@
+from .config import ConfigUnit
+from typing import Optional
+
+
+class ServicesListConfig(ConfigUnit):
+    NAME = 'services_list'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'type': 'list',
+            'empty': False,
+            'schema': {
+                'type': 'string'
+            }
+        }
+
+
+class LinuxBoardsConfig(ConfigUnit):
+    NAME = 'linux_boards'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'type': 'dict',
+            'schema': {
+                'mdns': {'type': 'string', 'required': True},
+                'board': {'type': 'string', 'required': True},
+                'network': {
+                    'type': 'list',
+                    'required': True,
+                    'empty': False,
+                    'allowed': ['wifi', 'ethernet']
+                },
+                'ram': {'type': 'integer', 'required': True},
+                'online': {'type': 'boolean', 'required': True},
+
+                # optional
+                'services': {
+                    'type': 'list',
+                    'empty': False,
+                    'allowed': ServicesListConfig().get()
+                },
+                'ext_hdd': {
+                    'type': 'list',
+                    'schema': {
+                        'type': 'dict',
+                        'schema': {
+                            'mountpoint': {'type': 'string', 'required': True},
+                            'size': {'type': 'integer', 'required': True}
+                        }
+                    },
+                },
+            }
+        }
diff --git a/include/py/homekit/config/config.py b/include/py/homekit/config/config.py
new file mode 100644
index 0000000..7344386
--- /dev/null
+++ b/include/py/homekit/config/config.py
@@ -0,0 +1,387 @@
+import yaml
+import logging
+import os
+import cerberus
+import cerberus.errors
+
+from abc import ABC
+from typing import Optional, Any, MutableMapping, Union
+from argparse import ArgumentParser
+from enum import Enum, auto
+from os.path import join, isdir, isfile
+from ..util import Addr
+
+
+class MyValidator(cerberus.Validator):
+    def _normalize_coerce_addr(self, value):
+        return Addr.fromstring(value)
+
+
+MyValidator.types_mapping['addr'] = cerberus.TypeDefinition('Addr', (Addr,), ())
+
+
+CONFIG_DIRECTORIES = (
+    join(os.environ['HOME'], '.config', 'homekit'),
+    '/etc/homekit'
+)
+
+
+class RootSchemaType(Enum):
+    DEFAULT = auto()
+    DICT = auto()
+    LIST = auto()
+
+
+class BaseConfigUnit(ABC):
+    _data: MutableMapping[str, Any]
+    _logger: logging.Logger
+
+    def __init__(self):
+        self._data = {}
+        self._logger = logging.getLogger(self.__class__.__name__)
+
+    def __getitem__(self, key):
+        return self._data[key]
+
+    def __setitem__(self, key, value):
+        raise NotImplementedError('overwriting config values is prohibited')
+
+    def __contains__(self, key):
+        return key in self._data
+
+    def load_from(self, path: str):
+        with open(path, 'r') as fd:
+            self._data = yaml.safe_load(fd)
+
+    def get(self,
+            key: Optional[str] = None,
+            default=None):
+        if key is None:
+            return self._data
+
+        cur = self._data
+        pts = key.split('.')
+        for i in range(len(pts)):
+            k = pts[i]
+            if i < len(pts)-1:
+                if k not in cur:
+                    raise KeyError(f'key {k} not found')
+            else:
+                return cur[k] if k in cur else default
+            cur = self._data[k]
+
+        raise KeyError(f'option {key} not found')
+
+
+class ConfigUnit(BaseConfigUnit):
+    NAME = 'dumb'
+
+    def __init__(self, name=None, load=True):
+        super().__init__()
+
+        self._data = {}
+        self._logger = logging.getLogger(self.__class__.__name__)
+
+        if self.NAME != 'dumb' and load:
+            self.load_from(self.get_config_path())
+            self.validate()
+
+        elif name is not None:
+            self.NAME = name
+
+    @classmethod
+    def get_config_path(cls, name=None) -> str:
+        if name is None:
+            name = cls.NAME
+            if name is None:
+                raise ValueError('get_config_path: name is none')
+
+        for dirname in CONFIG_DIRECTORIES:
+            if isdir(dirname):
+                filename = join(dirname, f'{name}.yaml')
+                if isfile(filename):
+                    return filename
+
+        raise IOError(f'\'{name}.yaml\' not found')
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return None
+
+    @classmethod
+    def _addr_schema(cls, required=False, **kwargs):
+        return {
+            'type': 'addr',
+            'coerce': Addr.fromstring,
+            'required': required,
+            **kwargs
+        }
+
+    def validate(self):
+        schema = self.schema()
+        if not schema:
+            self._logger.warning('validate: no schema')
+            return
+
+        if isinstance(self, AppConfigUnit):
+            schema['logging'] = {
+                'type': 'dict',
+                'schema': {
+                    'logging': {'type': 'boolean'}
+                }
+            }
+
+        rst = RootSchemaType.DEFAULT
+        try:
+            if schema['type'] == 'dict':
+                rst = RootSchemaType.DICT
+            elif schema['type'] == 'list':
+                rst = RootSchemaType.LIST
+            elif schema['roottype'] == 'dict':
+                del schema['roottype']
+                rst = RootSchemaType.DICT
+        except KeyError:
+            pass
+
+        v = MyValidator()
+
+        if rst == RootSchemaType.DICT:
+            normalized = v.validated({'document': self._data},
+                                     {'document': {
+                                         'type': 'dict',
+                                         'keysrules': {'type': 'string'},
+                                         'valuesrules': schema
+                                     }})['document']
+        elif rst == RootSchemaType.LIST:
+            v = MyValidator()
+            normalized = v.validated({'document': self._data}, {'document': schema})['document']
+        else:
+            normalized = v.validated(self._data, schema)
+
+        self._data = normalized
+
+        try:
+            self.custom_validator(self._data)
+        except Exception as e:
+            raise cerberus.DocumentError(f'{self.__class__.__name__}: {str(e)}')
+
+    @staticmethod
+    def custom_validator(data):
+        pass
+
+    def get_addr(self, key: str):
+        return Addr.fromstring(self.get(key))
+
+
+class AppConfigUnit(ConfigUnit):
+    _logging_verbose: bool
+    _logging_fmt: Optional[str]
+    _logging_file: Optional[str]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(load=False, *args, **kwargs)
+        self._logging_verbose = False
+        self._logging_fmt = None
+        self._logging_file = None
+
+    def logging_set_fmt(self, fmt: str) -> None:
+        self._logging_fmt = fmt
+
+    def logging_get_fmt(self) -> Optional[str]:
+        try:
+            return self['logging']['default_fmt']
+        except KeyError:
+            return self._logging_fmt
+
+    def logging_set_file(self, file: str) -> None:
+        self._logging_file = file
+
+    def logging_get_file(self) -> Optional[str]:
+        try:
+            return self['logging']['file']
+        except KeyError:
+            return self._logging_file
+
+    def logging_set_verbose(self):
+        self._logging_verbose = True
+
+    def logging_is_verbose(self) -> bool:
+        try:
+            return bool(self['logging']['verbose'])
+        except KeyError:
+            return self._logging_verbose
+
+
+class TranslationUnit(BaseConfigUnit):
+    pass
+
+
+class Translation:
+    LANGUAGES = ('en', 'ru')
+    _langs: dict[str, TranslationUnit]
+
+    def __init__(self, name: str):
+        super().__init__()
+        self._langs = {}
+        for lang in self.LANGUAGES:
+            for dirname in CONFIG_DIRECTORIES:
+                if isdir(dirname):
+                    filename = join(dirname, f'i18n-{lang}', f'{name}.yaml')
+                    if lang in self._langs:
+                        raise RuntimeError(f'{name}: translation unit for lang \'{lang}\' already loaded')
+                    self._langs[lang] = TranslationUnit()
+                    self._langs[lang].load_from(filename)
+        diff = set()
+        for data in self._langs.values():
+            diff ^= data.get().keys()
+        if len(diff) > 0:
+            raise RuntimeError(f'{name}: translation units have difference in keys: ' + ', '.join(diff))
+
+    def get(self, lang: str) -> TranslationUnit:
+        return self._langs[lang]
+
+
+class Config:
+    app_name: Optional[str]
+    app_config: AppConfigUnit
+
+    def __init__(self):
+        self.app_name = None
+        self.app_config = AppConfigUnit()
+
+    def load_app(self,
+                 name: Optional[Union[str, AppConfigUnit, bool]] = None,
+                 use_cli=True,
+                 parser: ArgumentParser = None,
+                 no_config=False):
+        global app_config
+
+        if not no_config \
+                and not isinstance(name, str) \
+                and not isinstance(name, bool) \
+                and issubclass(name, AppConfigUnit) or name == AppConfigUnit:
+            self.app_name = name.NAME
+            self.app_config = name()
+            app_config = self.app_config
+        else:
+            self.app_name = name if isinstance(name, str) else None
+
+        if self.app_name is None and not use_cli:
+            raise RuntimeError('either config name must be none or use_cli must be True')
+
+        no_config = name is False or no_config
+        path = None
+
+        if use_cli:
+            if parser is None:
+                parser = ArgumentParser()
+            if not no_config:
+                parser.add_argument('-c', '--config', type=str, required=name is None,
+                                    help='Path to the config in TOML or YAML format')
+            parser.add_argument('-V', '--verbose', action='store_true')
+            parser.add_argument('--log-file', type=str)
+            parser.add_argument('--log-default-fmt', action='store_true')
+            args = parser.parse_args()
+
+            if not no_config and args.config:
+                path = args.config
+
+            if args.verbose:
+                self.app_config.logging_set_verbose()
+            if args.log_file:
+                self.app_config.logging_set_file(args.log_file)
+            if args.log_default_fmt:
+                self.app_config.logging_set_fmt(args.log_default_fmt)
+
+        if not isinstance(name, ConfigUnit):
+            if not no_config and path is None:
+                path = ConfigUnit.get_config_path(name=self.app_name)
+
+            if not no_config:
+                self.app_config.load_from(path)
+                self.app_config.validate()
+
+        setup_logging(self.app_config.logging_is_verbose(),
+                      self.app_config.logging_get_file(),
+                      self.app_config.logging_get_fmt())
+
+        if use_cli:
+            return args
+
+
+config = Config()
+
+
+def is_development_mode() -> bool:
+    if 'HK_MODE' in os.environ and os.environ['HK_MODE'] == 'dev':
+        return True
+
+    return ('logging' in config.app_config) and ('verbose' in config.app_config['logging']) and (config.app_config['logging']['verbose'] is True)
+
+
+def setup_logging(verbose=False, log_file=None, default_fmt=None):
+    logging_level = logging.INFO
+    if is_development_mode() or verbose:
+        logging_level = logging.DEBUG
+        _add_logging_level('TRACE', logging.DEBUG-5)
+
+    log_config = {'level': logging_level}
+    if not default_fmt:
+        log_config['format'] = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+
+    if log_file is not None:
+        log_config['filename'] = log_file
+        log_config['encoding'] = 'utf-8'
+
+    logging.basicConfig(**log_config)
+
+
+# https://stackoverflow.com/questions/2183233/how-to-add-a-custom-loglevel-to-pythons-logging-facility/35804945#35804945
+def _add_logging_level(levelName, levelNum, methodName=None):
+    """
+    Comprehensively adds a new logging level to the `logging` module and the
+    currently configured logging class.
+
+    `levelName` becomes an attribute of the `logging` module with the value
+    `levelNum`. `methodName` becomes a convenience method for both `logging`
+    itself and the class returned by `logging.getLoggerClass()` (usually just
+    `logging.Logger`). If `methodName` is not specified, `levelName.lower()` is
+    used.
+
+    To avoid accidental clobberings of existing attributes, this method will
+    raise an `AttributeError` if the level name is already an attribute of the
+    `logging` module or if the method name is already present
+
+    Example
+    -------
+    >>> addLoggingLevel('TRACE', logging.DEBUG - 5)
+    >>> logging.getLogger(__name__).setLevel("TRACE")
+    >>> logging.getLogger(__name__).trace('that worked')
+    >>> logging.trace('so did this')
+    >>> logging.TRACE
+    5
+
+    """
+    if not methodName:
+        methodName = levelName.lower()
+
+    if hasattr(logging, levelName):
+        raise AttributeError('{} already defined in logging module'.format(levelName))
+    if hasattr(logging, methodName):
+        raise AttributeError('{} already defined in logging module'.format(methodName))
+    if hasattr(logging.getLoggerClass(), methodName):
+        raise AttributeError('{} already defined in logger class'.format(methodName))
+
+    # This method was inspired by the answers to Stack Overflow post
+    # http://stackoverflow.com/q/2183233/2988730, especially
+    # http://stackoverflow.com/a/13638084/2988730
+    def logForLevel(self, message, *args, **kwargs):
+        if self.isEnabledFor(levelNum):
+            self._log(levelNum, message, args, **kwargs)
+    def logToRoot(message, *args, **kwargs):
+        logging.log(levelNum, message, *args, **kwargs)
+
+    logging.addLevelName(levelNum, levelName)
+    setattr(logging, levelName, levelNum)
+    setattr(logging.getLoggerClass(), methodName, logForLevel)
+    setattr(logging, methodName, logToRoot)
\ No newline at end of file
diff --git a/include/py/homekit/database/__init__.py b/include/py/homekit/database/__init__.py
new file mode 100644
index 0000000..b50cbce
--- /dev/null
+++ b/include/py/homekit/database/__init__.py
@@ -0,0 +1,29 @@
+import importlib
+
+__all__ = [
+    'get_mysql',
+    'mysql_now',
+    'get_clickhouse',
+    'SimpleState',
+
+    'SensorsDatabase',
+    'InverterDatabase',
+    'BotsDatabase'
+]
+
+
+def __getattr__(name: str):
+    if name in __all__:
+        if name.endswith('Database'):
+            file = name[:-8].lower()
+        elif 'mysql' in name:
+            file = 'mysql'
+        elif 'clickhouse' in name:
+            file = 'clickhouse'
+        else:
+            file = 'simple_state'
+
+        module = importlib.import_module(f'.{file}', __name__)
+        return getattr(module, name)
+
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
diff --git a/include/py/homekit/database/__init__.pyi b/include/py/homekit/database/__init__.pyi
new file mode 100644
index 0000000..31aae5d
--- /dev/null
+++ b/include/py/homekit/database/__init__.pyi
@@ -0,0 +1,11 @@
+from .mysql import (
+    get_mysql as get_mysql,
+    mysql_now as mysql_now
+)
+from .clickhouse import get_clickhouse as get_clickhouse
+
+from simple_state import SimpleState as SimpleState
+
+from .sensors import SensorsDatabase as SensorsDatabase
+from .inverter import InverterDatabase as InverterDatabase
+from .bots import BotsDatabase as BotsDatabase
diff --git a/include/py/homekit/database/_base.py b/include/py/homekit/database/_base.py
new file mode 100644
index 0000000..c01e62b
--- /dev/null
+++ b/include/py/homekit/database/_base.py
@@ -0,0 +1,9 @@
+import os
+
+
+def get_data_root_directory(name: str) -> str:
+    return os.path.join(
+        os.environ['HOME'],
+        '.config',
+        'homekit',
+        'data')
\ No newline at end of file
diff --git a/include/py/homekit/database/bots.py b/include/py/homekit/database/bots.py
new file mode 100644
index 0000000..cde48b9
--- /dev/null
+++ b/include/py/homekit/database/bots.py
@@ -0,0 +1,106 @@
+import pytz
+
+from .mysql import mysql_now, MySQLDatabase, datetime_fmt
+from ..api.types import (
+    BotType,
+    SoundSensorLocation
+)
+from typing import Optional, List, Tuple
+from datetime import datetime
+from html import escape
+
+
+class OpenwrtLogRecord:
+    id: int
+    log_time: datetime
+    received_time: datetime
+    text: str
+
+    def __init__(self, id, text, log_time, received_time):
+        self.id = id
+        self.text = text
+        self.log_time = log_time
+        self.received_time = received_time
+
+    def __repr__(self):
+        return f"<b>{self.log_time.strftime('%H:%M:%S')}</b> {escape(self.text)}"
+
+
+class BotsDatabase(MySQLDatabase):
+    def add_request(self,
+                    bot: BotType,
+                    user_id: int,
+                    message: str):
+        with self.cursor() as cursor:
+            cursor.execute("INSERT INTO requests_log (user_id, message, bot, time) VALUES (%s, %s, %s, %s)",
+                           (user_id, message, bot.name.lower(), mysql_now()))
+        self.commit()
+
+    def add_openwrt_logs(self,
+                         lines: List[Tuple[datetime, str]],
+                         access_point: int):
+        now = datetime.now()
+        with self.cursor() as cursor:
+            for line in lines:
+                time, text = line
+                cursor.execute("INSERT INTO openwrt (log_time, received_time, text, ap) VALUES (%s, %s, %s, %s)",
+                               (time.strftime(datetime_fmt), now.strftime(datetime_fmt), text, access_point))
+        self.commit()
+
+    def add_sound_hits(self,
+                       hits: List[Tuple[SoundSensorLocation, int]],
+                       time: datetime):
+        with self.cursor() as cursor:
+            for loc, count in hits:
+                cursor.execute("INSERT INTO sound_hits (location, `time`, hits) VALUES (%s, %s, %s)",
+                               (loc.name.lower(), time.strftime(datetime_fmt), count))
+            self.commit()
+
+    def get_sound_hits(self,
+                       location: SoundSensorLocation,
+                       after: Optional[datetime] = None,
+                       last: Optional[int] = None) -> List[dict]:
+        with self.cursor(dictionary=True) as cursor:
+            sql = "SELECT `time`, hits FROM sound_hits WHERE location=%s"
+            args = [location.name.lower()]
+
+            if after:
+                sql += ' AND `time` >= %s ORDER BY time DESC'
+                args.append(after)
+            elif last:
+                sql += ' ORDER BY time DESC LIMIT 0, %s'
+                args.append(last)
+            else:
+                raise ValueError('no `after`, no `last`, what do you expect?')
+
+            cursor.execute(sql, tuple(args))
+            data = []
+            for row in cursor.fetchall():
+                data.append({
+                    'time': row['time'],
+                    'hits': row['hits']
+                })
+            return data
+
+    def get_openwrt_logs(self,
+                         filter_text: str,
+                         min_id: int,
+                         access_point: int,
+                         limit: int = None) -> List[OpenwrtLogRecord]:
+        tz = pytz.timezone('Europe/Moscow')
+        with self.cursor(dictionary=True) as cursor:
+            sql = "SELECT * FROM openwrt WHERE ap=%s AND text LIKE %s AND id > %s"
+            if limit is not None:
+                sql += f" LIMIT {limit}"
+
+            cursor.execute(sql, (access_point, f'%{filter_text}%', min_id))
+            data = []
+            for row in cursor.fetchall():
+                data.append(OpenwrtLogRecord(
+                    id=int(row['id']),
+                    text=row['text'],
+                    log_time=row['log_time'].astimezone(tz),
+                    received_time=row['received_time'].astimezone(tz)
+                ))
+
+            return data
diff --git a/include/py/homekit/database/clickhouse.py b/include/py/homekit/database/clickhouse.py
new file mode 100644
index 0000000..d0ec283
--- /dev/null
+++ b/include/py/homekit/database/clickhouse.py
@@ -0,0 +1,39 @@
+import logging
+
+from zoneinfo import ZoneInfo
+from datetime import datetime
+from clickhouse_driver import Client as ClickhouseClient
+from ..config import is_development_mode
+
+_links = {}
+
+
+def get_clickhouse(db: str) -> ClickhouseClient:
+    if db not in _links:
+        _links[db] = ClickhouseClient.from_url(f'clickhouse://localhost/{db}')
+
+    return _links[db]
+
+
+class ClickhouseDatabase:
+    def __init__(self, db: str):
+        self.db = get_clickhouse(db)
+
+        self.server_timezone = self.db.execute('SELECT timezone()')[0][0]
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+    def query(self, *args, **kwargs):
+        settings = {'use_client_time_zone': True}
+        kwargs['settings'] = settings
+
+        if 'no_tz_fix' not in kwargs and len(args) > 1 and isinstance(args[1], dict):
+            for k, v in args[1].items():
+                if isinstance(v, datetime):
+                    args[1][k] = v.astimezone(tz=ZoneInfo(self.server_timezone))
+
+        result = self.db.execute(*args, **kwargs)
+
+        if is_development_mode():
+            self.logger.debug(args[0] if len(args) == 1 else args[0] % args[1])
+
+        return result
diff --git a/include/py/homekit/database/inverter.py b/include/py/homekit/database/inverter.py
new file mode 100644
index 0000000..fc3f74f
--- /dev/null
+++ b/include/py/homekit/database/inverter.py
@@ -0,0 +1,212 @@
+from time import time
+from datetime import datetime, timedelta
+from typing import Optional
+from collections import namedtuple
+
+from .clickhouse import ClickhouseDatabase
+
+
+IntervalList = list[list[Optional[datetime]]]
+
+
+class InverterDatabase(ClickhouseDatabase):
+    def __init__(self):
+        super().__init__('solarmon')
+
+    def add_generation(self, home_id: int, client_time: int, watts: int) -> None:
+        self.db.execute(
+            'INSERT INTO generation (ClientTime, ReceivedTime, HomeID, Watts) VALUES',
+            [[client_time, round(time()), home_id, watts]]
+        )
+
+    def add_status(self, home_id: int,
+                   client_time: int,
+                   grid_voltage: int,
+                   grid_freq: int,
+                   ac_output_voltage: int,
+                   ac_output_freq: int,
+                   ac_output_apparent_power: int,
+                   ac_output_active_power: int,
+                   output_load_percent: int,
+                   battery_voltage: int,
+                   battery_voltage_scc: int,
+                   battery_voltage_scc2: int,
+                   battery_discharge_current: int,
+                   battery_charge_current: int,
+                   battery_capacity: int,
+                   inverter_heat_sink_temp: int,
+                   mppt1_charger_temp: int,
+                   mppt2_charger_temp: int,
+                   pv1_input_power: int,
+                   pv2_input_power: int,
+                   pv1_input_voltage: int,
+                   pv2_input_voltage: int,
+                   mppt1_charger_status: int,
+                   mppt2_charger_status: int,
+                   battery_power_direction: int,
+                   dc_ac_power_direction: int,
+                   line_power_direction: int,
+                   load_connected: int) -> None:
+        self.db.execute("""INSERT INTO status (
+            ClientTime,
+            ReceivedTime,
+            HomeID,
+            GridVoltage,
+            GridFrequency,
+            ACOutputVoltage,
+            ACOutputFrequency,
+            ACOutputApparentPower,
+            ACOutputActivePower,
+            OutputLoadPercent,
+            BatteryVoltage,
+            BatteryVoltageSCC,
+            BatteryVoltageSCC2,
+            BatteryDischargingCurrent,
+            BatteryChargingCurrent,
+            BatteryCapacity,
+            HeatSinkTemp,
+            MPPT1ChargerTemp,
+            MPPT2ChargerTemp,
+            PV1InputPower,
+            PV2InputPower,
+            PV1InputVoltage,
+            PV2InputVoltage,
+            MPPT1ChargerStatus,
+            MPPT2ChargerStatus,
+            BatteryPowerDirection,
+            DCACPowerDirection,
+            LinePowerDirection,
+            LoadConnected) VALUES""", [[
+            client_time,
+            round(time()),
+            home_id,
+            grid_voltage,
+            grid_freq,
+            ac_output_voltage,
+            ac_output_freq,
+            ac_output_apparent_power,
+            ac_output_active_power,
+            output_load_percent,
+            battery_voltage,
+            battery_voltage_scc,
+            battery_voltage_scc2,
+            battery_discharge_current,
+            battery_charge_current,
+            battery_capacity,
+            inverter_heat_sink_temp,
+            mppt1_charger_temp,
+            mppt2_charger_temp,
+            pv1_input_power,
+            pv2_input_power,
+            pv1_input_voltage,
+            pv2_input_voltage,
+            mppt1_charger_status,
+            mppt2_charger_status,
+            battery_power_direction,
+            dc_ac_power_direction,
+            line_power_direction,
+            load_connected
+        ]])
+
+    def get_consumed_energy(self, dt_from: datetime, dt_to: datetime) -> float:
+        rows = self.query('SELECT ClientTime, ACOutputActivePower FROM status'
+                          ' WHERE ClientTime >= %(from)s AND ClientTime <= %(to)s'
+                          ' ORDER BY ClientTime', {'from': dt_from, 'to': dt_to})
+        prev_time = None
+        prev_wh = 0
+
+        ws = 0  # watt-seconds
+        for t, wh in rows:
+            if prev_time is not None:
+                n = (t - prev_time).total_seconds()
+                ws += prev_wh * n
+
+            prev_time = t
+            prev_wh = wh
+
+        return ws / 3600  # convert to watt-hours
+
+    def get_intervals_by_condition(self,
+                                   dt_from: datetime,
+                                   dt_to: datetime,
+                                   cond_start: str,
+                                   cond_end: str) -> IntervalList:
+        rows = None
+        ranges = [[None, None]]
+
+        while rows is None or len(rows) > 0:
+            if ranges[len(ranges)-1][0] is None:
+                condition = cond_start
+                range_idx = 0
+            else:
+                condition = cond_end
+                range_idx = 1
+
+            rows = self.query('SELECT ClientTime FROM status '
+                              f'WHERE ClientTime > %(from)s AND ClientTime <= %(to)s AND {condition}'
+                              ' ORDER BY ClientTime LIMIT 1',
+                              {'from': dt_from, 'to': dt_to})
+            if not rows:
+                break
+
+            row = rows[0]
+
+            ranges[len(ranges) - 1][range_idx] = row[0]
+            if range_idx == 1:
+                ranges.append([None, None])
+
+            dt_from = row[0]
+
+        if ranges[len(ranges)-1][0] is None:
+            ranges.pop()
+        elif ranges[len(ranges)-1][1] is None:
+            ranges[len(ranges)-1][1] = dt_to - timedelta(seconds=1)
+
+        return ranges
+
+    def get_grid_connected_intervals(self, dt_from: datetime, dt_to: datetime) -> IntervalList:
+        return self.get_intervals_by_condition(dt_from, dt_to, 'GridFrequency > 0', 'GridFrequency = 0')
+
+    def get_grid_used_intervals(self, dt_from: datetime, dt_to: datetime) -> IntervalList:
+        return self.get_intervals_by_condition(dt_from,
+                                               dt_to,
+                                               "LinePowerDirection = 'Input'",
+                                               "LinePowerDirection != 'Input'")
+
+    def get_grid_consumed_energy(self, dt_from: datetime, dt_to: datetime) -> float:
+        PrevData = namedtuple('PrevData', 'time, pd, bat_chg, bat_dis, wh')
+
+        ws = 0  # watt-seconds
+        amps = 0  # amper-seconds
+
+        intervals = self.get_grid_used_intervals(dt_from, dt_to)
+        for dt_start, dt_end in intervals:
+            fields = ', '.join([
+                'ClientTime',
+                'DCACPowerDirection',
+                'BatteryChargingCurrent',
+                'BatteryDischargingCurrent',
+                'ACOutputActivePower'
+            ])
+            rows = self.query(f'SELECT {fields} FROM status'
+                              ' WHERE ClientTime >= %(from)s AND ClientTime < %(to)s ORDER BY ClientTime',
+                              {'from': dt_start, 'to': dt_end})
+
+            prev = PrevData(time=None, pd=None, bat_chg=None, bat_dis=None, wh=None)
+            for ct, pd, bat_chg, bat_dis, wh in rows:
+                if prev.time is not None:
+                    n = (ct-prev.time).total_seconds()
+                    ws += prev.wh * n
+
+                    if pd == 'DC/AC':
+                        amps -= prev.bat_dis * n
+                    elif pd == 'AC/DC':
+                        amps += prev.bat_chg * n
+
+                prev = PrevData(time=ct, pd=pd, bat_chg=bat_chg, bat_dis=bat_dis, wh=wh)
+
+        amps /= 3600
+        wh = ws / 3600
+        wh += amps*48
+
+        return wh
diff --git a/include/py/homekit/database/inverter_time_formats.py b/include/py/homekit/database/inverter_time_formats.py
new file mode 100644
index 0000000..7c37d30
--- /dev/null
+++ b/include/py/homekit/database/inverter_time_formats.py
@@ -0,0 +1,2 @@
+FormatTime = '%Y-%m-%d %H:%M:%S'
+FormatDate = '%Y-%m-%d'
diff --git a/include/py/homekit/database/mysql.py b/include/py/homekit/database/mysql.py
new file mode 100644
index 0000000..fe97cd4
--- /dev/null
+++ b/include/py/homekit/database/mysql.py
@@ -0,0 +1,47 @@
+import time
+import logging
+
+from mysql.connector import connect, MySQLConnection, Error
+from typing import Optional
+from ..config import config
+
+link: Optional[MySQLConnection] = None
+logger = logging.getLogger(__name__)
+
+datetime_fmt = '%Y-%m-%d %H:%M:%S'
+
+
+def get_mysql() -> MySQLConnection:
+    global link
+
+    if link is not None:
+        return link
+
+    link = connect(
+        host=config['mysql']['host'],
+        user=config['mysql']['user'],
+        password=config['mysql']['password'],
+        database=config['mysql']['database'],
+    )
+    link.time_zone = '+01:00'
+    return link
+
+
+def mysql_now() -> str:
+    return time.strftime('%Y-%m-%d %H:%M:%S')
+
+
+class MySQLDatabase:
+    def __init__(self):
+        self.db = get_mysql()
+
+    def cursor(self, **kwargs):
+        try:
+            self.db.ping(reconnect=True, attempts=2)
+        except Error as e:
+            logger.exception(e)
+            self.db = get_mysql()
+        return self.db.cursor(**kwargs)
+
+    def commit(self):
+        self.db.commit()
diff --git a/include/py/homekit/database/sensors.py b/include/py/homekit/database/sensors.py
new file mode 100644
index 0000000..8155108
--- /dev/null
+++ b/include/py/homekit/database/sensors.py
@@ -0,0 +1,69 @@
+from time import time
+from datetime import datetime
+from typing import Tuple, List
+from .clickhouse import ClickhouseDatabase
+from ..api.types import TemperatureSensorLocation
+
+
+def get_temperature_table(sensor: TemperatureSensorLocation) -> str:
+    if sensor == TemperatureSensorLocation.DIANA:
+        return 'temp_diana'
+
+    elif sensor == TemperatureSensorLocation.STREET:
+        return 'temp_street'
+
+    elif sensor == TemperatureSensorLocation.BIG_HOUSE_1:
+        return 'temp'
+
+    elif sensor == TemperatureSensorLocation.BIG_HOUSE_2:
+        return 'temp_roof'
+
+    elif sensor == TemperatureSensorLocation.BIG_HOUSE_ROOM:
+        return 'temp_room'
+
+    elif sensor == TemperatureSensorLocation.SPB1:
+        return 'temp_spb1'
+
+
+class SensorsDatabase(ClickhouseDatabase):
+    def __init__(self):
+        super().__init__('home')
+
+    def add_temperature(self,
+                        home_id: int,
+                        client_time: int,
+                        sensor: TemperatureSensorLocation,
+                        temp: int,
+                        rh: int):
+        table = get_temperature_table(sensor)
+        sql = """INSERT INTO """ + table + """ (
+                        ClientTime,
+                        ReceivedTime,
+                        HomeID,
+                        Temperature,
+                        RelativeHumidity
+                        ) VALUES"""
+        self.db.execute(sql, [[
+            client_time,
+            int(time()),
+            home_id,
+            temp,
+            rh
+        ]])
+
+    def get_temperature_recordings(self,
+                                   sensor: TemperatureSensorLocation,
+                                   time_range: Tuple[datetime, datetime],
+                                   home_id=1) -> List[tuple]:
+        table = get_temperature_table(sensor)
+        sql = f"""SELECT ClientTime, Temperature, RelativeHumidity 
+            FROM {table}
+            WHERE ClientTime >= %(from)s AND ClientTime <= %(to)s
+            ORDER BY ClientTime"""
+        dt_from, dt_to = time_range
+
+        data = self.query(sql, {
+            'from': dt_from,
+            'to': dt_to
+        })
+        return [(date, temp/100, humidity/100) for date, temp, humidity in data]
diff --git a/include/py/homekit/database/simple_state.py b/include/py/homekit/database/simple_state.py
new file mode 100644
index 0000000..2b8ebe7
--- /dev/null
+++ b/include/py/homekit/database/simple_state.py
@@ -0,0 +1,48 @@
+import os
+import json
+import atexit
+
+from ._base import get_data_root_directory
+
+
+class SimpleState:
+    def __init__(self,
+                 name: str,
+                 default: dict = None):
+        if default is None:
+            default = {}
+        elif type(default) is not dict:
+            raise TypeError('default must be dictionary')
+
+        path = os.path.join(get_data_root_directory(), name)
+        if not os.path.exists(path):
+            self._data = default
+        else:
+            with open(path, 'r') as f:
+                self._data = json.loads(f.read())
+
+        self._file = path
+        atexit.register(self.__cleanup)
+
+    def __cleanup(self):
+        if hasattr(self, '_file'):
+            with open(self._file, 'w') as f:
+                f.write(json.dumps(self._data))
+        atexit.unregister(self.__cleanup)
+
+    def __del__(self):
+        if 'open' in __builtins__:
+            self.__cleanup()
+
+    def __getitem__(self, key):
+        return self._data[key]
+
+    def __setitem__(self, key, value):
+        self._data[key] = value
+
+    def __contains__(self, key):
+        return key in self._data
+
+    def __delitem__(self, key):
+        if key in self._data:
+            del self._data[key]
diff --git a/include/py/homekit/database/sqlite.py b/include/py/homekit/database/sqlite.py
new file mode 100644
index 0000000..0af1f54
--- /dev/null
+++ b/include/py/homekit/database/sqlite.py
@@ -0,0 +1,67 @@
+import sqlite3
+import os.path
+import logging
+
+from ._base import get_data_root_directory
+from ..config import config, is_development_mode
+
+
+def _get_database_path(name: str) -> str:
+    return os.path.join(
+        get_data_root_directory(),
+        f'{name}.db')
+
+
+class SQLiteBase:
+    SCHEMA = 1
+
+    def __init__(self, name=None, check_same_thread=False):
+        if name is None:
+            name = config.app_config['database_name']
+        database_path = _get_database_path(name)
+        if not os.path.exists(os.path.dirname(database_path)):
+            os.makedirs(os.path.dirname(database_path))
+
+        self.logger = logging.getLogger(self.__class__.__name__)
+        self.sqlite = sqlite3.connect(database_path, check_same_thread=check_same_thread)
+
+        if is_development_mode():
+            self.sql_logger = logging.getLogger(self.__class__.__name__)
+            self.sql_logger.setLevel('TRACE')
+            self.sqlite.set_trace_callback(self.sql_logger.trace)
+
+        sqlite_version = self._get_sqlite_version()
+        self.logger.debug(f'SQLite version: {sqlite_version}')
+
+        schema_version = self.schema_get_version()
+        self.logger.debug(f'Schema version: {schema_version}')
+
+        self.schema_init(schema_version)
+        self.schema_set_version(self.SCHEMA)
+
+    def __del__(self):
+        if self.sqlite:
+            self.sqlite.commit()
+            self.sqlite.close()
+
+    def _get_sqlite_version(self) -> str:
+        cursor = self.sqlite.cursor()
+        cursor.execute("SELECT sqlite_version()")
+        return cursor.fetchone()[0]
+
+    def schema_get_version(self) -> int:
+        cursor = self.sqlite.execute('PRAGMA user_version')
+        return int(cursor.fetchone()[0])
+
+    def schema_set_version(self, v) -> None:
+        self.sqlite.execute('PRAGMA user_version={:d}'.format(v))
+        self.logger.info(f'Schema set to {v}')
+
+    def cursor(self) -> sqlite3.Cursor:
+        return self.sqlite.cursor()
+
+    def commit(self) -> None:
+        return self.sqlite.commit()
+
+    def schema_init(self, version: int) -> None:
+        raise ValueError(f'{self.__class__.__name__}: must override schema_init')
diff --git a/include/py/homekit/http/__init__.py b/include/py/homekit/http/__init__.py
new file mode 100644
index 0000000..6030e95
--- /dev/null
+++ b/include/py/homekit/http/__init__.py
@@ -0,0 +1,2 @@
+from .http import serve, ok, routes, HTTPServer
+from aiohttp.web import FileResponse, StreamResponse, Request, Response
diff --git a/include/py/homekit/http/http.py b/include/py/homekit/http/http.py
new file mode 100644
index 0000000..3e70751
--- /dev/null
+++ b/include/py/homekit/http/http.py
@@ -0,0 +1,106 @@
+import logging
+import asyncio
+
+from aiohttp import web
+from aiohttp.web import Response
+from aiohttp.web_exceptions import HTTPNotFound
+
+from ..util import stringify, format_tb, Addr
+
+
+_logger = logging.getLogger(__name__)
+
+
+@web.middleware
+async def errors_handler_middleware(request, handler):
+    try:
+        response = await handler(request)
+        return response
+
+    except HTTPNotFound:
+        return web.json_response({'error': 'not found'}, status=404)
+
+    except Exception as exc:
+        _logger.exception(exc)
+        data = {
+            'error': exc.__class__.__name__,
+            'message': exc.message if hasattr(exc, 'message') else str(exc)
+        }
+        tb = format_tb(exc)
+        if tb:
+            data['stacktrace'] = tb
+
+        return web.json_response(data, status=500)
+
+
+def serve(addr: Addr, route_table: web.RouteTableDef, handle_signals: bool = True):
+    app = web.Application()
+    app.add_routes(route_table)
+    app.middlewares.append(errors_handler_middleware)
+
+    host, port = addr
+
+    web.run_app(app,
+                host=host,
+                port=port,
+                handle_signals=handle_signals)
+
+
+def routes() -> web.RouteTableDef:
+    return web.RouteTableDef()
+
+
+def ok(data=None):
+    if data is None:
+        data = 1
+    response = {'response': data}
+    return web.json_response(response, dumps=stringify)
+
+
+class HTTPServer:
+    def __init__(self, addr: Addr, handle_errors=True):
+        self.addr = addr
+        self.app = web.Application()
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+        if handle_errors:
+            self.app.middlewares.append(errors_handler_middleware)
+
+    def _add_route(self,
+                   method: str,
+                   path: str,
+                   handler: callable):
+        self.app.router.add_routes([getattr(web, method)(path, handler)])
+
+    def get(self, path, handler):
+        self._add_route('get', path, handler)
+
+    def post(self, path, handler):
+        self._add_route('post', path, handler)
+
+    def put(self, path, handler):
+        self._add_route('put', path, handler)
+
+    def delete(self, path, handler):
+        self._add_route('delete', path, handler)
+
+    def run(self, event_loop=None, handle_signals=True):
+        if not event_loop:
+            event_loop = asyncio.get_event_loop()
+
+        runner = web.AppRunner(self.app, handle_signals=handle_signals)
+        event_loop.run_until_complete(runner.setup())
+
+        host, port = self.addr
+        site = web.TCPSite(runner, host=host, port=port)
+        event_loop.run_until_complete(site.start())
+
+        self.logger.info(f'Server started at http://{host}:{port}')
+
+        event_loop.run_forever()
+
+    def ok(self, data=None):
+        return ok(data)
+
+    def plain(self, text: str):
+        return Response(text=text, content_type='text/plain')
diff --git a/include/py/homekit/inverter/__init__.py b/include/py/homekit/inverter/__init__.py
new file mode 100644
index 0000000..8831ef3
--- /dev/null
+++ b/include/py/homekit/inverter/__init__.py
@@ -0,0 +1,3 @@
+from .monitor import InverterMonitor
+from .inverter_wrapper import wrapper_instance
+from .util import beautify_table
diff --git a/include/py/homekit/inverter/config.py b/include/py/homekit/inverter/config.py
new file mode 100644
index 0000000..e284dfe
--- /dev/null
+++ b/include/py/homekit/inverter/config.py
@@ -0,0 +1,13 @@
+from ..config import ConfigUnit
+from typing import Optional
+
+
+class InverterdConfig(ConfigUnit):
+    NAME = 'inverterd'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'remote_addr': {'type': 'string'},
+            'local_addr': {'type': 'string'},
+        }
\ No newline at end of file
diff --git a/include/py/homekit/inverter/emulator.py b/include/py/homekit/inverter/emulator.py
new file mode 100644
index 0000000..e86b8bb
--- /dev/null
+++ b/include/py/homekit/inverter/emulator.py
@@ -0,0 +1,556 @@
+import asyncio
+import logging
+
+from inverterd import Format
+
+from typing import Union
+from enum import Enum
+from ..util import Addr, stringify
+
+
+class InverterEnum(Enum):
+    def as_text(self) -> str:
+        raise RuntimeError('abstract method')
+
+
+class BatteryType(InverterEnum):
+    AGM = 0
+    Flooded = 1
+    User = 2
+
+    def as_text(self) -> str:
+        return ('AGM', 'Flooded', 'User')[self.value]
+
+
+class InputVoltageRange(InverterEnum):
+    Appliance = 0
+    USP = 1
+
+    def as_text(self) -> str:
+        return ('Appliance', 'USP')[self.value]
+
+
+class OutputSourcePriority(InverterEnum):
+    SolarUtilityBattery = 0
+    SolarBatteryUtility = 1
+
+    def as_text(self) -> str:
+        return ('Solar-Utility-Battery', 'Solar-Battery-Utility')[self.value]
+
+
+class ChargeSourcePriority(InverterEnum):
+    SolarFirst = 0
+    SolarAndUtility = 1
+    SolarOnly = 2
+
+    def as_text(self) -> str:
+        return ('Solar-First', 'Solar-and-Utility', 'Solar-only')[self.value]
+
+
+class MachineType(InverterEnum):
+    OffGridTie = 0
+    GridTie = 1
+
+    def as_text(self) -> str:
+        return ('Off-Grid-Tie', 'Grid-Tie')[self.value]
+
+
+class Topology(InverterEnum):
+    TransformerLess = 0
+    Transformer = 1
+
+    def as_text(self) -> str:
+        return ('Transformer-less', 'Transformer')[self.value]
+
+
+class OutputMode(InverterEnum):
+    SingleOutput = 0
+    ParallelOutput = 1
+    Phase_1_of_3 = 2
+    Phase_2_of_3 = 3
+    Phase_3_of_3 = 4
+
+    def as_text(self) -> str:
+        return (
+            'Single output',
+            'Parallel output',
+            'Phase 1 of 3-phase output',
+            'Phase 2 of 3-phase output',
+            'Phase 3 of 3-phase'
+        )[self.value]
+
+
+class SolarPowerPriority(InverterEnum):
+    BatteryLoadUtility = 0
+    LoadBatteryUtility = 1
+
+    def as_text(self) -> str:
+        return ('Battery-Load-Utility', 'Load-Battery-Utility')[self.value]
+
+
+class MPPTChargerStatus(InverterEnum):
+    Abnormal = 0
+    NotCharging = 1
+    Charging = 2
+
+    def as_text(self) -> str:
+        return ('Abnormal', 'Not charging', 'Charging')[self.value]
+
+
+class BatteryPowerDirection(InverterEnum):
+    DoNothing = 0
+    Charge = 1
+    Discharge = 2
+
+    def as_text(self) -> str:
+        return ('Do nothing', 'Charge', 'Discharge')[self.value]
+
+
+class DC_AC_PowerDirection(InverterEnum):
+    DoNothing = 0
+    AC_DC = 1
+    DC_AC = 2
+
+    def as_text(self) -> str:
+        return ('Do nothing', 'AC/DC', 'DC/AC')[self.value]
+
+
+class LinePowerDirection(InverterEnum):
+    DoNothing = 0
+    Input = 1
+    Output = 2
+
+    def as_text(self) -> str:
+        return ('Do nothing', 'Input', 'Output')[self.value]
+
+
+class WorkingMode(InverterEnum):
+    PowerOnMode = 0
+    StandbyMode = 1
+    BypassMode = 2
+    BatteryMode = 3
+    FaultMode = 4
+    HybridMode = 5
+
+    def as_text(self) -> str:
+        return (
+            'Power on mode',
+            'Standby mode',
+            'Bypass mode',
+            'Battery mode',
+            'Fault mode',
+            'Hybrid mode'
+        )[self.value]
+
+
+class ParallelConnectionStatus(InverterEnum):
+    NotExistent = 0
+    Existent = 1
+
+    def as_text(self) -> str:
+        return ('Non-existent', 'Existent')[self.value]
+
+
+class LoadConnectionStatus(InverterEnum):
+    Disconnected = 0
+    Connected = 1
+
+    def as_text(self) -> str:
+        return ('Disconnected', 'Connected')[self.value]
+
+
+class ConfigurationStatus(InverterEnum):
+    Default = 0
+    Changed = 1
+
+    def as_text(self) -> str:
+        return ('Default', 'Changed')[self.value]
+
+
+_g_human_readable = {"grid_voltage": "Grid voltage",
+                     "grid_freq": "Grid frequency",
+                     "ac_output_voltage": "AC output voltage",
+                     "ac_output_freq": "AC output frequency",
+                     "ac_output_apparent_power": "AC output apparent power",
+                     "ac_output_active_power": "AC output active power",
+                     "output_load_percent": "Output load percent",
+                     "battery_voltage": "Battery voltage",
+                     "battery_voltage_scc": "Battery voltage from SCC",
+                     "battery_voltage_scc2": "Battery voltage from SCC2",
+                     "battery_discharge_current": "Battery discharge current",
+                     "battery_charge_current": "Battery charge current",
+                     "battery_capacity": "Battery capacity",
+                     "inverter_heat_sink_temp": "Inverter heat sink temperature",
+                     "mppt1_charger_temp": "MPPT1 charger temperature",
+                     "mppt2_charger_temp": "MPPT2 charger temperature",
+                     "pv1_input_power": "PV1 input power",
+                     "pv2_input_power": "PV2 input power",
+                     "pv1_input_voltage": "PV1 input voltage",
+                     "pv2_input_voltage": "PV2 input voltage",
+                     "configuration_status": "Configuration state",
+                     "mppt1_charger_status": "MPPT1 charger status",
+                     "mppt2_charger_status": "MPPT2 charger status",
+                     "load_connected": "Load connection",
+                     "battery_power_direction": "Battery power direction",
+                     "dc_ac_power_direction": "DC/AC power direction",
+                     "line_power_direction": "Line power direction",
+                     "local_parallel_id": "Local parallel ID",
+                     "ac_input_rating_voltage": "AC input rating voltage",
+                     "ac_input_rating_current": "AC input rating current",
+                     "ac_output_rating_voltage": "AC output rating voltage",
+                     "ac_output_rating_freq": "AC output rating frequency",
+                     "ac_output_rating_current": "AC output rating current",
+                     "ac_output_rating_apparent_power": "AC output rating apparent power",
+                     "ac_output_rating_active_power": "AC output rating active power",
+                     "battery_rating_voltage": "Battery rating voltage",
+                     "battery_recharge_voltage": "Battery re-charge voltage",
+                     "battery_redischarge_voltage": "Battery re-discharge voltage",
+                     "battery_under_voltage": "Battery under voltage",
+                     "battery_bulk_voltage": "Battery bulk voltage",
+                     "battery_float_voltage": "Battery float voltage",
+                     "battery_type": "Battery type",
+                     "max_charge_current": "Max charge current",
+                     "max_ac_charge_current": "Max AC charge current",
+                     "input_voltage_range": "Input voltage range",
+                     "output_source_priority": "Output source priority",
+                     "charge_source_priority": "Charge source priority",
+                     "parallel_max_num": "Parallel max num",
+                     "machine_type": "Machine type",
+                     "topology": "Topology",
+                     "output_mode": "Output mode",
+                     "solar_power_priority": "Solar power priority",
+                     "mppt": "MPPT string",
+                     "fault_code": "Fault code",
+                     "line_fail": "Line fail",
+                     "output_circuit_short": "Output circuit short",
+                     "inverter_over_temperature": "Inverter over temperature",
+                     "fan_lock": "Fan lock",
+                     "battery_voltage_high": "Battery voltage high",
+                     "battery_low": "Battery low",
+                     "battery_under": "Battery under",
+                     "over_load": "Over load",
+                     "eeprom_fail": "EEPROM fail",
+                     "power_limit": "Power limit",
+                     "pv1_voltage_high": "PV1 voltage high",
+                     "pv2_voltage_high": "PV2 voltage high",
+                     "mppt1_overload_warning": "MPPT1 overload warning",
+                     "mppt2_overload_warning": "MPPT2 overload warning",
+                     "battery_too_low_to_charge_for_scc1": "Battery too low to charge for SCC1",
+                     "battery_too_low_to_charge_for_scc2": "Battery too low to charge for SCC2",
+                     "buzzer": "Buzzer",
+                     "overload_bypass": "Overload bypass function",
+                     "escape_to_default_screen_after_1min_timeout": "Escape to default screen after 1min timeout",
+                     "overload_restart": "Overload restart",
+                     "over_temp_restart": "Over temperature restart",
+                     "backlight_on": "Backlight on",
+                     "alarm_on_on_primary_source_interrupt": "Alarm on on primary source interrupt",
+                     "fault_code_record": "Fault code record",
+                     "wh": "Wh"}
+
+
+class InverterEmulator:
+    def __init__(self, addr: Addr, wait=True):
+        self.status = {"grid_voltage": {"unit": "V", "value": 236.3},
+                       "grid_freq": {"unit": "Hz", "value": 50.0},
+                       "ac_output_voltage": {"unit": "V", "value": 229.9},
+                       "ac_output_freq": {"unit": "Hz", "value": 50.0},
+                       "ac_output_apparent_power": {"unit": "VA", "value": 207},
+                       "ac_output_active_power": {"unit": "Wh", "value": 146},
+                       "output_load_percent": {"unit": "%", "value": 4},
+                       "battery_voltage": {"unit": "V", "value": 49.1},
+                       "battery_voltage_scc": {"unit": "V", "value": 0.0},
+                       "battery_voltage_scc2": {"unit": "V", "value": 0.0},
+                       "battery_discharge_current": {"unit": "A", "value": 3},
+                       "battery_charge_current": {"unit": "A", "value": 0},
+                       "battery_capacity": {"unit": "%", "value": 69},
+                       "inverter_heat_sink_temp": {"unit": "°C", "value": 17},
+                       "mppt1_charger_temp": {"unit": "°C", "value": 0},
+                       "mppt2_charger_temp": {"unit": "°C", "value": 0},
+                       "pv1_input_power": {"unit": "Wh", "value": 0},
+                       "pv2_input_power": {"unit": "Wh", "value": 0},
+                       "pv1_input_voltage": {"unit": "V", "value": 0.0},
+                       "pv2_input_voltage": {"unit": "V", "value": 0.0},
+                       "configuration_status": ConfigurationStatus.Default,
+                       "mppt1_charger_status": MPPTChargerStatus.Abnormal,
+                       "mppt2_charger_status": MPPTChargerStatus.Abnormal,
+                       "load_connected": LoadConnectionStatus.Connected,
+                       "battery_power_direction": BatteryPowerDirection.Discharge,
+                       "dc_ac_power_direction": DC_AC_PowerDirection.DC_AC,
+                       "line_power_direction": LinePowerDirection.DoNothing,
+                       "local_parallel_id": 0}
+
+        self.rated = {"ac_input_rating_voltage": {"unit": "V", "value": 230.0},
+                      "ac_input_rating_current": {"unit": "A", "value": 21.7},
+                      "ac_output_rating_voltage": {"unit": "V", "value": 230.0},
+                      "ac_output_rating_freq": {"unit": "Hz", "value": 50.0},
+                      "ac_output_rating_current": {"unit": "A", "value": 21.7},
+                      "ac_output_rating_apparent_power": {"unit": "VA", "value": 5000},
+                      "ac_output_rating_active_power": {"unit": "Wh", "value": 5000},
+                      "battery_rating_voltage": {"unit": "V", "value": 48.0},
+                      "battery_recharge_voltage": {"unit": "V", "value": 48.0},
+                      "battery_redischarge_voltage": {"unit": "V", "value": 55.0},
+                      "battery_under_voltage": {"unit": "V", "value": 42.0},
+                      "battery_bulk_voltage": {"unit": "V", "value": 57.6},
+                      "battery_float_voltage": {"unit": "V", "value": 54.0},
+                      "battery_type": BatteryType.User,
+                      "max_charge_current": {"unit": "A", "value": 60},
+                      "max_ac_charge_current": {"unit": "A", "value": 30},
+                      "input_voltage_range": InputVoltageRange.Appliance,
+                      "output_source_priority": OutputSourcePriority.SolarBatteryUtility,
+                      "charge_source_priority": ChargeSourcePriority.SolarAndUtility,
+                      "parallel_max_num": 6,
+                      "machine_type": MachineType.OffGridTie,
+                      "topology": Topology.TransformerLess,
+                      "output_mode": OutputMode.SingleOutput,
+                      "solar_power_priority": SolarPowerPriority.LoadBatteryUtility,
+                      "mppt": "2"}
+
+        self.errors = {"fault_code": 0,
+                       "line_fail": False,
+                       "output_circuit_short": False,
+                       "inverter_over_temperature": False,
+                       "fan_lock": False,
+                       "battery_voltage_high": False,
+                       "battery_low": False,
+                       "battery_under": False,
+                       "over_load": False,
+                       "eeprom_fail": False,
+                       "power_limit": False,
+                       "pv1_voltage_high": False,
+                       "pv2_voltage_high": False,
+                       "mppt1_overload_warning": False,
+                       "mppt2_overload_warning": False,
+                       "battery_too_low_to_charge_for_scc1": False,
+                       "battery_too_low_to_charge_for_scc2": False}
+
+        self.flags = {"buzzer": False,
+                      "overload_bypass": True,
+                      "escape_to_default_screen_after_1min_timeout": False,
+                      "overload_restart": True,
+                      "over_temp_restart": True,
+                      "backlight_on": False,
+                      "alarm_on_on_primary_source_interrupt": True,
+                      "fault_code_record": False}
+
+        self.day_generated = 1000
+
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+        host, port = addr
+        asyncio.run(self.run_server(host, port, wait))
+        # self.max_ac_charge_current = 30
+        # self.max_charge_current = 60
+        # self.charge_thresholds = [48, 54]
+
+    async def run_server(self, host, port, wait: bool):
+        server = await asyncio.start_server(self.client_handler, host, port)
+        async with server:
+            self.logger.info(f'listening on {host}:{port}')
+            if wait:
+                await server.serve_forever()
+            else:
+                asyncio.ensure_future(server.serve_forever())
+
+    async def client_handler(self, reader, writer):
+        client_fmt = Format.JSON
+
+        def w(s: str):
+            writer.write(s.encode('utf-8'))
+
+        def return_error(message=None):
+            w('err\r\n')
+            if message:
+                if client_fmt in (Format.JSON, Format.SIMPLE_JSON):
+                    w(stringify({
+                        'result': 'error',
+                        'message': message
+                    }))
+                elif client_fmt in (Format.TABLE, Format.SIMPLE_TABLE):
+                    w(f'error: {message}')
+                w('\r\n')
+            w('\r\n')
+
+        def return_ok(data=None):
+            w('ok\r\n')
+            if client_fmt in (Format.JSON, Format.SIMPLE_JSON):
+                jdata = {
+                    'result': 'ok'
+                }
+                if data:
+                    jdata['data'] = data
+                w(stringify(jdata))
+                w('\r\n')
+            elif data:
+                w(data)
+                w('\r\n')
+            w('\r\n')
+
+        request = None
+        while request != 'quit':
+            try:
+                request = await reader.read(255)
+                if request == b'\x04':
+                    break
+                request = request.decode('utf-8').strip()
+            except Exception:
+                break
+
+            if request.startswith('format '):
+                requested_format = request[7:]
+                try:
+                    client_fmt = Format(requested_format)
+                except ValueError:
+                    return_error('invalid format')
+
+                return_ok()
+
+            elif request.startswith('exec '):
+                buf = request[5:].split(' ')
+                command = buf[0]
+                args = buf[1:]
+
+                try:
+                    return_ok(self.process_command(client_fmt, command, *args))
+                except ValueError as e:
+                    return_error(str(e))
+
+            else:
+                return_error(f'invalid token: {request}')
+
+            try:
+                await writer.drain()
+            except ConnectionResetError as e:
+                # self.logger.exception(e)
+                pass
+
+        writer.close()
+
+    def process_command(self, fmt: Format, c: str, *args) -> Union[dict, str, list[int], None]:
+        ac_charge_currents = [2, 10, 20, 30, 40, 50, 60]
+
+        if c == 'get-status':
+            return self.format_dict(self.status, fmt)
+
+        elif c == 'get-rated':
+            return self.format_dict(self.rated, fmt)
+
+        elif c == 'get-errors':
+            return self.format_dict(self.errors, fmt)
+
+        elif c == 'get-flags':
+            return self.format_dict(self.flags, fmt)
+
+        elif c == 'get-day-generated':
+            return self.format_dict({'wh': 1000}, fmt)
+
+        elif c == 'get-allowed-ac-charge-currents':
+            return self.format_list(ac_charge_currents, fmt)
+
+        elif c == 'set-max-ac-charge-current':
+            if int(args[0]) != 0:
+                raise ValueError(f'invalid machine id: {args[0]}')
+            amps = int(args[1])
+            if amps not in ac_charge_currents:
+                raise ValueError(f'invalid value: {amps}')
+            self.rated['max_ac_charge_current']['value'] = amps
+
+        elif c == 'set-charge-thresholds':
+            self.rated['battery_recharge_voltage']['value'] = float(args[0])
+            self.rated['battery_redischarge_voltage']['value'] = float(args[1])
+
+        elif c == 'set-output-source-priority':
+            self.rated['output_source_priority'] = OutputSourcePriority.SolarBatteryUtility if args[0] == 'SBU' else OutputSourcePriority.SolarUtilityBattery
+
+        elif c == 'set-battery-cutoff-voltage':
+            self.rated['battery_under_voltage']['value'] = float(args[0])
+
+        elif c == 'set-flag':
+            flag = args[0]
+            val = bool(int(args[1]))
+
+            if flag == 'BUZZ':
+                k = 'buzzer'
+            elif flag == 'OLBP':
+                k = 'overload_bypass'
+            elif flag == 'LCDE':
+                k = 'escape_to_default_screen_after_1min_timeout'
+            elif flag == 'OLRS':
+                k = 'overload_restart'
+            elif flag == 'OTRS':
+                k = 'over_temp_restart'
+            elif flag == 'BLON':
+                k = 'backlight_on'
+            elif flag == 'ALRM':
+                k = 'alarm_on_on_primary_source_interrupt'
+            elif flag == 'FTCR':
+                k = 'fault_code_record'
+            else:
+                raise ValueError('invalid flag')
+
+            self.flags[k] = val
+
+        else:
+            raise ValueError(f'{c}: unsupported command')
+
+    @staticmethod
+    def format_list(values: list, fmt: Format) -> Union[str, list]:
+        if fmt in (Format.JSON, Format.SIMPLE_JSON):
+            return values
+        return '\n'.join(map(lambda v: str(v), values))
+
+    @staticmethod
+    def format_dict(data: dict, fmt: Format) -> Union[str, dict]:
+        new_data = {}
+        for k, v in data.items():
+            new_val = None
+            if fmt in (Format.JSON, Format.TABLE, Format.SIMPLE_TABLE):
+                if isinstance(v, dict):
+                    new_val = v
+                elif isinstance(v, InverterEnum):
+                    new_val = v.as_text()
+                else:
+                    new_val = v
+            elif fmt == Format.SIMPLE_JSON:
+                if isinstance(v, dict):
+                    new_val = v['value']
+                elif isinstance(v, InverterEnum):
+                    new_val = v.value
+                else:
+                    new_val = str(v)
+            new_data[k] = new_val
+
+        if fmt in (Format.JSON, Format.SIMPLE_JSON):
+            return new_data
+
+        lines = []
+
+        if fmt == Format.SIMPLE_TABLE:
+            for k, v in new_data.items():
+                buf = k
+                if isinstance(v, dict):
+                    buf += ' ' + str(v['value']) + ' ' + v['unit']
+                elif isinstance(v, InverterEnum):
+                    buf += ' ' + v.as_text()
+                else:
+                    buf += ' ' + str(v)
+                lines.append(buf)
+
+        elif fmt == Format.TABLE:
+            max_k_len = 0
+            for k in new_data.keys():
+                if len(_g_human_readable[k]) > max_k_len:
+                    max_k_len = len(_g_human_readable[k])
+            for k, v in new_data.items():
+                buf = _g_human_readable[k] + ':'
+                buf += ' ' * (max_k_len - len(_g_human_readable[k]) + 1)
+                if isinstance(v, dict):
+                    buf += str(v['value']) + ' ' + v['unit']
+                elif isinstance(v, InverterEnum):
+                    buf += v.as_text()
+                elif isinstance(v, bool):
+                    buf += str(int(v))
+                else:
+                    buf += str(v)
+                lines.append(buf)
+
+        return '\n'.join(lines)
diff --git a/include/py/homekit/inverter/inverter_wrapper.py b/include/py/homekit/inverter/inverter_wrapper.py
new file mode 100644
index 0000000..df2c2fc
--- /dev/null
+++ b/include/py/homekit/inverter/inverter_wrapper.py
@@ -0,0 +1,48 @@
+import json
+
+from threading import Lock
+from inverterd import (
+    Format,
+    Client as InverterClient,
+    InverterError
+)
+
+_lock = Lock()
+
+
+class InverterClientWrapper:
+    def __init__(self):
+        self._inverter = None
+        self._host = None
+        self._port = None
+
+    def init(self, host: str, port: int):
+        self._host = host
+        self._port = port
+        self.create()
+
+    def create(self):
+        self._inverter = InverterClient(host=self._host, port=self._port)
+        self._inverter.connect()
+
+    def exec(self, command: str, arguments: tuple = (), format=Format.JSON):
+        with _lock:
+            try:
+                self._inverter.format(format)
+                response = self._inverter.exec(command, arguments)
+                if format == Format.JSON:
+                    response = json.loads(response)
+                return response
+            except InverterError as e:
+                raise e
+            except Exception as e:
+                # silently try to reconnect
+                try:
+                    self.create()
+                except Exception:
+                    pass
+                raise e
+
+
+wrapper_instance = InverterClientWrapper()
+
diff --git a/include/py/homekit/inverter/monitor.py b/include/py/homekit/inverter/monitor.py
new file mode 100644
index 0000000..86f75ac
--- /dev/null
+++ b/include/py/homekit/inverter/monitor.py
@@ -0,0 +1,499 @@
+import logging
+import time
+
+from .types import *
+from threading import Thread
+from typing import Callable, Optional
+from .inverter_wrapper import wrapper_instance as inverter
+from inverterd import InverterError
+from ..util import Stopwatch, StopwatchError
+from ..config import config
+
+logger = logging.getLogger(__name__)
+
+
+def _pd_from_string(pd: str) -> BatteryPowerDirection:
+    if pd == 'Discharge':
+        return BatteryPowerDirection.DISCHARGING
+    elif pd == 'Charge':
+        return BatteryPowerDirection.CHARGING
+    elif pd == 'Do nothing':
+        return BatteryPowerDirection.DO_NOTHING
+    else:
+        raise ValueError(f'invalid power direction: {pd}')
+
+
+class MonitorConfig:
+    def __getattr__(self, item):
+        return config['monitor'][item]
+
+
+cfg = MonitorConfig()
+
+
+"""
+TODO:
+- поддержать возможность ручного (через бота) переключения тока заряда вверх и вниз
+- поддержать возможность бесшовного перезапуска бота, когда монитор понимает, что зарядка уже идет, и он
+  не запускает программу с начала, а продолжает с уже существующей позиции. Уведомления при этом можно не
+  присылать совсем, либо прислать какое-то одно приложение, в духе "программа была перезапущена"
+"""
+
+
+class InverterMonitor(Thread):
+    charging_event_handler: Optional[Callable]
+    battery_event_handler: Optional[Callable]
+    util_event_handler: Optional[Callable]
+    error_handler: Optional[Callable]
+    osp_change_cb: Optional[Callable]
+    osp: Optional[OutputSourcePriority]
+
+    def __init__(self):
+        super().__init__()
+        self.setName('InverterMonitor')
+
+        self.interrupted = False
+        self.min_allowed_current = 0
+        self.ac_mode = None
+        self.osp = None
+
+        # Event handlers for the bot.
+        self.charging_event_handler = None
+        self.battery_event_handler = None
+        self.util_event_handler = None
+        self.error_handler = None
+        self.osp_change_cb = None
+
+        # Currents list, defined in the bot config.
+        self.currents = cfg.gen_currents
+        self.currents.sort()
+
+        # We start charging at lowest possible current, then increase it once per minute (or so) to the maximum level.
+        # This is done so that the load on the generator increases smoothly, not abruptly. Generator will thank us.
+        self.current_change_direction = CurrentChangeDirection.UP
+        self.next_current_enter_time = 0
+        self.active_current_idx = -1
+
+        self.battery_state = BatteryState.NORMAL
+        self.charging_state = ChargingState.NOT_CHARGING
+
+        # 'Mostly-charged' means that we've already lowered the charging current to the level
+        # at which batteries are charging pretty slow. So instead of burning gasoline and shaking the air,
+        # we can just turn the generator off at this point.
+        self.mostly_charged = False
+
+        # The stopwatch is used to measure how long does the battery voltage exceeds the float voltage level.
+        # We don't want to damage our batteries, right?
+        self.floating_stopwatch = Stopwatch()
+
+        # State variables for utilities charging program
+        self.util_ac_present = None
+        self.util_pd = None
+        self.util_solar = None
+
+    @property
+    def active_current(self) -> Optional[int]:
+        try:
+            if self.active_current_idx < 0:
+                return None
+            return self.currents[self.active_current_idx]
+        except IndexError:
+            return None
+
+    def run(self):
+        # Check allowed currents and validate the config.
+        allowed_currents = list(inverter.exec('get-allowed-ac-charge-currents')['data'])
+        allowed_currents.sort()
+
+        for a in self.currents:
+            if a not in allowed_currents:
+                raise ValueError(f'invalid value {a} in gen_currents list')
+
+        self.min_allowed_current = min(allowed_currents)
+
+        # Reading rated configuration
+        rated = inverter.exec('get-rated')['data']
+        self.osp = OutputSourcePriority.from_text(rated['output_source_priority'])
+
+        # Read data and run implemented programs every 2 seconds.
+        while not self.interrupted:
+            try:
+                response = inverter.exec('get-status')
+                if response['result'] != 'ok':
+                    logger.error('get-status failed:', response)
+                else:
+                    gs = response['data']
+
+                    ac = gs['grid_voltage']['value'] > 0 or gs['grid_freq']['value'] > 0
+                    solar = gs['pv1_input_voltage']['value'] > 0 or gs['pv2_input_voltage']['value'] > 0
+                    solar_input = gs['pv1_input_power']['value']
+                    v = float(gs['battery_voltage']['value'])
+                    load_watts = int(gs['ac_output_active_power']['value'])
+                    pd = _pd_from_string(gs['battery_power_direction'])
+
+                    logger.debug(f'got status: ac={ac}, solar={solar}, v={v}, pd={pd}')
+
+                    if self.ac_mode == ACMode.GENERATOR:
+                        self.gen_charging_program(ac, solar, v, pd)
+
+                    elif self.ac_mode == ACMode.UTILITIES:
+                        self.utilities_monitoring_program(ac, solar, v, load_watts, solar_input, pd)
+
+                    if not ac or pd != BatteryPowerDirection.CHARGING:
+                        # if AC is disconnected or not charging, run the low voltage checking program
+                        self.low_voltage_program(v, load_watts)
+
+                    elif self.battery_state != BatteryState.NORMAL:
+                        # AC is connected and the battery is charging, assume battery level is normal
+                        self.battery_state = BatteryState.NORMAL
+
+            except InverterError as e:
+                logger.exception(e)
+
+            time.sleep(2)
+
+    def utilities_monitoring_program(self,
+                                     ac: bool,                  # whether AC is connected
+                                     solar: bool,               # whether MPPT is active
+                                     v: float,                  # battery voltage
+                                     load_watts: int,           # load, wh
+                                     solar_input: int,          # input from solar panels, wh
+                                     pd: BatteryPowerDirection  # current power direction
+                                     ):
+        pd_event_send = False
+        if self.util_solar is None or solar != self.util_solar:
+            self.util_solar = solar
+            if solar and self.util_ac_present and self.util_pd == BatteryPowerDirection.CHARGING:
+                self.charging_event_handler(ChargingEvent.UTIL_CHARGING_STOPPED_SOLAR)
+                pd_event_send = True
+
+        if solar:
+            if v <= 48 and self.osp == OutputSourcePriority.SolarBatteryUtility:
+                self.osp_change_cb(OutputSourcePriority.SolarUtilityBattery, solar_input=solar_input, v=v)
+                self.osp = OutputSourcePriority.SolarUtilityBattery
+
+            if self.osp == OutputSourcePriority.SolarUtilityBattery and solar_input >= 900:
+                self.osp_change_cb(OutputSourcePriority.SolarBatteryUtility, solar_input=solar_input, v=v)
+                self.osp = OutputSourcePriority.SolarBatteryUtility
+
+        if self.util_ac_present is None or ac != self.util_ac_present:
+            self.util_event_handler(ACPresentEvent.CONNECTED if ac else ACPresentEvent.DISCONNECTED)
+            self.util_ac_present = ac
+
+        if self.util_pd is None or self.util_pd != pd:
+            self.util_pd = pd
+            if not pd_event_send and not solar:
+                if pd == BatteryPowerDirection.CHARGING:
+                    self.charging_event_handler(ChargingEvent.UTIL_CHARGING_STARTED)
+
+                elif pd == BatteryPowerDirection.DISCHARGING:
+                    self.charging_event_handler(ChargingEvent.UTIL_CHARGING_STOPPED)
+
+    def gen_charging_program(self,
+                             ac: bool,                  # whether AC is connected
+                             solar: bool,               # whether MPPT is active
+                             v: float,                  # current battery voltage
+                             pd: BatteryPowerDirection  # current power direction
+                             ):
+        if self.charging_state == ChargingState.NOT_CHARGING:
+            if ac and solar:
+                # Not charging because MPPT is active (solar line is connected).
+                # Notify users about it and change the current state.
+                self.charging_state = ChargingState.AC_BUT_SOLAR
+                self.charging_event_handler(ChargingEvent.AC_CHARGING_UNAVAILABLE_BECAUSE_SOLAR)
+                logger.info('entering AC_BUT_SOLAR state')
+            elif ac:
+                # Not charging, but AC is connected and ready to use.
+                # Start the charging program.
+                self.gen_start(pd)
+
+        elif self.charging_state == ChargingState.AC_BUT_SOLAR:
+            if not ac:
+                # AC charger has been disconnected. Since the state is AC_BUT_SOLAR,
+                # charging probably never even started. Stop the charging program.
+                self.gen_stop(ChargingState.NOT_CHARGING)
+            elif not solar:
+                # MPPT has been disconnected, and, since AC is still connected, we can
+                # try to start the charging program.
+                self.gen_start(pd)
+
+        elif self.charging_state in (ChargingState.AC_OK, ChargingState.AC_WAITING):
+            if not ac:
+                # Charging was in progress, but AC has been suddenly disconnected.
+                # Sad, but what can we do? Stop the charging program and return.
+                self.gen_stop(ChargingState.NOT_CHARGING)
+                return
+
+            if solar:
+                # Charging was in progress, but MPPT has been detected. Inverter doesn't charge
+                # batteries from AC when MPPT is active, so we have to pause our program.
+                self.charging_state = ChargingState.AC_BUT_SOLAR
+                self.charging_event_handler(ChargingEvent.AC_CHARGING_UNAVAILABLE_BECAUSE_SOLAR)
+                try:
+                    self.floating_stopwatch.pause()
+                except StopwatchError:
+                    msg = 'gen_charging_program: floating_stopwatch.pause() failed at (1)'
+                    logger.warning(msg)
+                    # self.error_handler(msg)
+                logger.info('solar power connected during charging, entering AC_BUT_SOLAR state')
+                return
+
+            # No surprises at this point, just check the values and make decisions based on them.
+            # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+            # We've reached the 'mostly-charged' point, the voltage level is not float,
+            # but inverter decided to stop charging (or somebody used a kettle, lol).
+            # Anyway, assume that charging is complete, stop the program, notify users and return.
+            if self.mostly_charged and v > (cfg.gen_floating_v - 1) and pd != BatteryPowerDirection.CHARGING:
+                self.gen_stop(ChargingState.AC_DONE)
+                return
+
+            # Monitor inverter power direction and notify users when it changes.
+            state = ChargingState.AC_OK if pd == BatteryPowerDirection.CHARGING else ChargingState.AC_WAITING
+            if state != self.charging_state:
+                self.charging_state = state
+
+                evt = ChargingEvent.AC_CHARGING_STARTED if state == ChargingState.AC_OK else ChargingEvent.AC_NOT_CHARGING
+                self.charging_event_handler(evt)
+
+            if self.floating_stopwatch.get_elapsed_time() >= cfg.gen_floating_time_max:
+                # We've been at a bulk voltage level too long, so we have to stop charging.
+                # Set the minimum current possible.
+
+                if self.current_change_direction == CurrentChangeDirection.UP:
+                    # This shouldn't happen, obviously an error.
+                    msg = 'gen_charging_program:'
+                    msg += ' been at bulk voltage level too long, but current change direction is still \'up\'!'
+                    msg += ' This is obviously an error, please fix it'
+                    logger.warning(msg)
+                    self.error_handler(msg)
+
+                self.gen_next_current(current=self.min_allowed_current)
+
+            elif self.active_current is not None:
+                # If voltage is greater than float voltage, keep the stopwatch ticking
+                if v > cfg.gen_floating_v and self.floating_stopwatch.is_paused():
+                    try:
+                        self.floating_stopwatch.go()
+                    except StopwatchError:
+                        msg = 'gen_charging_program: floating_stopwatch.go() failed at (2)'
+                        logger.warning(msg)
+                        self.error_handler(msg)
+                # Otherwise, pause it
+                elif v <= cfg.gen_floating_v and not self.floating_stopwatch.is_paused():
+                    try:
+                        self.floating_stopwatch.pause()
+                    except StopwatchError:
+                        msg = 'gen_charging_program: floating_stopwatch.pause() failed at (3)'
+                        logger.warning(msg)
+                        self.error_handler(msg)
+
+                # Charging current monitoring
+                if self.current_change_direction == CurrentChangeDirection.UP:
+                    # Generator is warming up in this code path
+
+                    if self.next_current_enter_time != 0 and pd != BatteryPowerDirection.CHARGING:
+                        # Generator was warming up and charging, but stopped (pd has changed).
+                        # Resetting to the minimum possible current
+                        logger.info(f'gen_charging_program (warming path): was charging but power direction suddeny changed. resetting to minimum current')
+                        self.next_current_enter_time = 0
+                        self.gen_next_current(current=self.min_allowed_current)
+
+                    elif self.next_current_enter_time == 0 and pd == BatteryPowerDirection.CHARGING:
+                        self.next_current_enter_time = time.time() + cfg.gen_raise_intervals[self.active_current_idx]
+                        logger.info(f'gen_charging_program (warming path): set next_current_enter_time to {self.next_current_enter_time}')
+
+                    elif self.next_current_enter_time != 0 and time.time() >= self.next_current_enter_time:
+                        logger.info('gen_charging_program (warming path): hit next_current_enter_time, calling gen_next_current()')
+                        self.gen_next_current()
+                else:
+                    # Gradually lower the current level, based on how close
+                    # battery voltage has come to the bulk level.
+                    if self.active_current >= 30:
+                        upper_bound = cfg.gen_cur30_v_limit
+                    elif self.active_current == 20:
+                        upper_bound = cfg.gen_cur20_v_limit
+                    else:
+                        upper_bound = cfg.gen_cur10_v_limit
+
+                    # Voltage is high enough already and it's close to bulk level; we hit the upper bound,
+                    # so let's lower the current
+                    if v >= upper_bound:
+                        self.gen_next_current()
+
+        elif self.charging_state == ChargingState.AC_DONE:
+            # We've already finished charging, but AC was connected. Not that it's disconnected,
+            # set the appropriate state and notify users.
+            if not ac:
+                self.gen_stop(ChargingState.NOT_CHARGING)
+
+    def gen_start(self, pd: BatteryPowerDirection):
+        if pd == BatteryPowerDirection.CHARGING:
+            self.charging_state = ChargingState.AC_OK
+            self.charging_event_handler(ChargingEvent.AC_CHARGING_STARTED)
+            logger.info('AC line connected and charging, entering AC_OK state')
+
+            # Continue the stopwatch, if needed
+            try:
+                self.floating_stopwatch.go()
+            except StopwatchError:
+                msg = 'floating_stopwatch.go() failed at ac_charging_start(), AC_OK path'
+                logger.warning(msg)
+                self.error_handler(msg)
+        else:
+            self.charging_state = ChargingState.AC_WAITING
+            self.charging_event_handler(ChargingEvent.AC_NOT_CHARGING)
+            logger.info('AC line connected but not charging yet, entering AC_WAITING state')
+
+            # Pause the stopwatch, if needed
+            try:
+                if not self.floating_stopwatch.is_paused():
+                    self.floating_stopwatch.pause()
+            except StopwatchError:
+                msg = 'floating_stopwatch.pause() failed at ac_charging_start(), AC_WAITING path'
+                logger.warning(msg)
+                self.error_handler(msg)
+
+        # idx == -1 means haven't started our program yet.
+        if self.active_current_idx == -1:
+            self.gen_next_current()
+            # self.set_hw_charging_current(self.min_allowed_current)
+
+    def gen_stop(self, reason: ChargingState):
+        self.charging_state = reason
+
+        if reason == ChargingState.AC_DONE:
+            event = ChargingEvent.AC_CHARGING_FINISHED
+        elif reason == ChargingState.NOT_CHARGING:
+            event = ChargingEvent.AC_DISCONNECTED
+        else:
+            raise ValueError(f'ac_charging_stop: unexpected reason {reason}')
+
+        logger.info(f'charging is finished, entering {reason} state')
+        self.charging_event_handler(event)
+
+        self.next_current_enter_time = 0
+        self.mostly_charged = False
+        self.active_current_idx = -1
+        self.floating_stopwatch.reset()
+        self.current_change_direction = CurrentChangeDirection.UP
+
+        self.set_hw_charging_current(self.min_allowed_current)
+
+    def gen_next_current(self, current=None):
+        if current is None:
+            try:
+                current = self._next_current()
+                logger.debug(f'gen_next_current: ready to change charging current to {current} A')
+            except IndexError:
+                logger.debug('gen_next_current: was going to change charging current, but no currents left; finishing charging program')
+                self.gen_stop(ChargingState.AC_DONE)
+                return
+
+        else:
+            try:
+                idx = self.currents.index(current)
+            except ValueError:
+                msg = f'gen_next_current: got current={current} but it\'s not in the currents list'
+                logger.error(msg)
+                self.error_handler(msg)
+                return
+            self.active_current_idx = idx
+
+        if self.current_change_direction == CurrentChangeDirection.DOWN:
+            if current == self.currents[0]:
+                self.mostly_charged = True
+                self.gen_stop(ChargingState.AC_DONE)
+
+            elif current == self.currents[1] and not self.mostly_charged:
+                self.mostly_charged = True
+                self.charging_event_handler(ChargingEvent.AC_MOSTLY_CHARGED)
+
+        self.set_hw_charging_current(current)
+
+    def set_hw_charging_current(self, current: int):
+        try:
+            response = inverter.exec('set-max-ac-charge-current', (0, current))
+            if response['result'] != 'ok':
+                logger.error(f'failed to change AC charging current to {current} A')
+                raise InverterError('set-max-ac-charge-current: inverterd reported error')
+            else:
+                self.charging_event_handler(ChargingEvent.AC_CURRENT_CHANGED, current=current)
+                logger.info(f'changed AC charging current to {current} A')
+        except InverterError as e:
+            self.error_handler(f'failed to set charging current to {current} A (caught InverterError)')
+            logger.exception(e)
+
+    def _next_current(self):
+        if self.current_change_direction == CurrentChangeDirection.UP:
+            self.active_current_idx += 1
+            if self.active_current_idx == len(self.currents)-1:
+                logger.info('_next_current: charging current power direction to DOWN')
+                self.current_change_direction = CurrentChangeDirection.DOWN
+            self.next_current_enter_time = 0
+        else:
+            if self.active_current_idx == 0:
+                raise IndexError('can\'t go lower')
+            self.active_current_idx -= 1
+
+        logger.info(f'_next_current: active_current_idx set to {self.active_current_idx}, returning current of {self.currents[self.active_current_idx]} A')
+        return self.currents[self.active_current_idx]
+
+    def low_voltage_program(self, v: float, load_watts: int):
+        crit_level = cfg.vcrit
+        low_level = cfg.vlow
+
+        if v <= crit_level:
+            state = BatteryState.CRITICAL
+        elif v <= low_level:
+            state = BatteryState.LOW
+        else:
+            state = BatteryState.NORMAL
+
+        if state != self.battery_state:
+            self.battery_state = state
+            self.battery_event_handler(state, v, load_watts)
+
+    def set_charging_event_handler(self, handler: Callable):
+        self.charging_event_handler = handler
+
+    def set_battery_event_handler(self, handler: Callable):
+        self.battery_event_handler = handler
+
+    def set_util_event_handler(self, handler: Callable):
+        self.util_event_handler = handler
+
+    def set_error_handler(self, handler: Callable):
+        self.error_handler = handler
+
+    def set_osp_need_change_callback(self, cb: Callable):
+        self.osp_change_cb = cb
+
+    def set_ac_mode(self, mode: ACMode):
+        self.ac_mode = mode
+
+    def notify_osp(self, osp: OutputSourcePriority):
+        self.osp = osp
+
+    def stop(self):
+        self.interrupted = True
+
+    def dump_status(self) -> dict:
+        return {
+            'interrupted': self.interrupted,
+            'currents': self.currents,
+            'active_current': self.active_current,
+            'current_change_direction': self.current_change_direction.name,
+            'battery_state': self.battery_state.name,
+            'charging_state': self.charging_state.name,
+            'mostly_charged': self.mostly_charged,
+            'floating_stopwatch_paused': self.floating_stopwatch.is_paused(),
+            'floating_stopwatch_elapsed': self.floating_stopwatch.get_elapsed_time(),
+            'time_now': time.time(),
+            'next_current_enter_time': self.next_current_enter_time,
+            'ac_mode': self.ac_mode,
+            'osp': self.osp,
+            'util_ac_present': self.util_ac_present,
+            'util_pd': self.util_pd.name,
+            'util_solar': self.util_solar
+        }
diff --git a/include/py/homekit/inverter/types.py b/include/py/homekit/inverter/types.py
new file mode 100644
index 0000000..57021f1
--- /dev/null
+++ b/include/py/homekit/inverter/types.py
@@ -0,0 +1,64 @@
+from enum import Enum, auto
+
+
+class BatteryPowerDirection(Enum):
+    DISCHARGING = auto()
+    CHARGING = auto()
+    DO_NOTHING = auto()
+
+
+class ChargingEvent(Enum):
+    AC_CHARGING_UNAVAILABLE_BECAUSE_SOLAR = auto()
+    AC_NOT_CHARGING = auto()
+    AC_CHARGING_STARTED = auto()
+    AC_DISCONNECTED = auto()
+    AC_CURRENT_CHANGED = auto()
+    AC_MOSTLY_CHARGED = auto()
+    AC_CHARGING_FINISHED = auto()
+
+    UTIL_CHARGING_STARTED = auto()
+    UTIL_CHARGING_STOPPED = auto()
+    UTIL_CHARGING_STOPPED_SOLAR = auto()
+
+
+class ACPresentEvent(Enum):
+    CONNECTED = auto()
+    DISCONNECTED = auto()
+
+
+class ChargingState(Enum):
+    NOT_CHARGING = auto()
+    AC_BUT_SOLAR = auto()
+    AC_WAITING = auto()
+    AC_OK = auto()
+    AC_DONE = auto()
+
+
+class CurrentChangeDirection(Enum):
+    UP = auto()
+    DOWN = auto()
+
+
+class BatteryState(Enum):
+    NORMAL = auto()
+    LOW = auto()
+    CRITICAL = auto()
+
+
+class ACMode(Enum):
+    GENERATOR = 'generator'
+    UTILITIES = 'utilities'
+
+
+class OutputSourcePriority(Enum):
+    SolarUtilityBattery = 'SUB'
+    SolarBatteryUtility = 'SBU'
+
+    @classmethod
+    def from_text(cls, s: str):
+        if s == 'Solar-Battery-Utility':
+            return cls.SolarBatteryUtility
+        elif s == 'Solar-Utility-Battery':
+            return cls.SolarUtilityBattery
+        else:
+            raise ValueError(f'unknown value: {s}')
\ No newline at end of file
diff --git a/include/py/homekit/inverter/util.py b/include/py/homekit/inverter/util.py
new file mode 100644
index 0000000..a577e6a
--- /dev/null
+++ b/include/py/homekit/inverter/util.py
@@ -0,0 +1,8 @@
+import re
+
+
+def beautify_table(s):
+    lines = s.split('\n')
+    lines = list(map(lambda line: re.sub(r'\s+', ' ', line), lines))
+    lines = list(map(lambda line: re.sub(r'(.*?): (.*)', r'<b>\1:</b> \2', line), lines))
+    return '\n'.join(lines)
diff --git a/include/py/homekit/media/__init__.py b/include/py/homekit/media/__init__.py
new file mode 100644
index 0000000..6923105
--- /dev/null
+++ b/include/py/homekit/media/__init__.py
@@ -0,0 +1,22 @@
+import importlib
+import itertools
+
+__map__ = {
+    'types': ['MediaNodeType'],
+    'record_client': ['SoundRecordClient', 'CameraRecordClient', 'RecordClient'],
+    'node_server': ['MediaNodeServer'],
+    'node_client': ['SoundNodeClient', 'CameraNodeClient', 'MediaNodeClient'],
+    'storage': ['SoundRecordStorage', 'ESP32CameraRecordStorage', 'SoundRecordFile', 'CameraRecordFile', 'RecordFile'],
+    'record': ['SoundRecorder', 'CameraRecorder']
+}
+
+__all__ = list(itertools.chain(*__map__.values()))
+
+
+def __getattr__(name):
+    if name in __all__:
+        for file, names in __map__.items():
+            if name in names:
+                module = importlib.import_module(f'.{file}', __name__)
+                return getattr(module, name)
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
diff --git a/include/py/homekit/media/__init__.pyi b/include/py/homekit/media/__init__.pyi
new file mode 100644
index 0000000..77c2176
--- /dev/null
+++ b/include/py/homekit/media/__init__.pyi
@@ -0,0 +1,27 @@
+from .types import (
+    MediaNodeType as MediaNodeType
+)
+from .record_client import (
+    SoundRecordClient as SoundRecordClient,
+    CameraRecordClient as CameraRecordClient,
+    RecordClient as RecordClient
+)
+from .node_server import (
+    MediaNodeServer as MediaNodeServer
+)
+from .node_client import (
+    SoundNodeClient as SoundNodeClient,
+    CameraNodeClient as CameraNodeClient,
+    MediaNodeClient as MediaNodeClient
+)
+from .storage import (
+    SoundRecordStorage as SoundRecordStorage,
+    ESP32CameraRecordStorage as ESP32CameraRecordStorage,
+    SoundRecordFile as SoundRecordFile,
+    CameraRecordFile as CameraRecordFile,
+    RecordFile as RecordFile
+)
+from .record import (
+    SoundRecorder as SoundRecorder,
+    CameraRecorder as CameraRecorder
+)
\ No newline at end of file
diff --git a/include/py/homekit/media/node_client.py b/include/py/homekit/media/node_client.py
new file mode 100644
index 0000000..eb39898
--- /dev/null
+++ b/include/py/homekit/media/node_client.py
@@ -0,0 +1,119 @@
+import requests
+import shutil
+import logging
+
+from typing import Optional, Union, List
+from .storage import RecordFile
+from ..util import Addr
+from ..api.errors import ApiResponseError
+
+
+class MediaNodeClient:
+    def __init__(self, addr: Addr):
+        self.endpoint = f'http://{addr[0]}:{addr[1]}'
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+    def record(self, duration: int):
+        return self._call('record/', params={"duration": duration})
+
+    def record_info(self, record_id: int):
+        return self._call(f'record/info/{record_id}/')
+
+    def record_forget(self, record_id: int):
+        return self._call(f'record/forget/{record_id}/')
+
+    def record_download(self, record_id: int, output: str):
+        return self._call(f'record/download/{record_id}/', save_to=output)
+
+    def storage_list(self, extended=False, as_objects=False) -> Union[List[str], List[dict], List[RecordFile]]:
+        r = self._call('storage/list/', params={'extended': int(extended)})
+        files = r['files']
+        if as_objects:
+            return self.record_list_from_serialized(files)
+        return files
+
+    @staticmethod
+    def record_list_from_serialized(files: Union[List[str], List[dict]]):
+        new_files = []
+        for f in files:
+            kwargs = {'remote': True}
+            if isinstance(f, dict):
+                name = f['filename']
+                kwargs['remote_filesize'] = f['filesize']
+            else:
+                name = f
+            item = RecordFile.create(name, **kwargs)
+            new_files.append(item)
+        return new_files
+
+    def storage_delete(self, file_id: str):
+        return self._call('storage/delete/', params={'file_id': file_id})
+
+    def storage_download(self, file_id: str, output: str):
+        return self._call('storage/download/', params={'file_id': file_id}, save_to=output)
+
+    def _call(self,
+              method: str,
+              params: dict = None,
+              save_to: Optional[str] = None):
+        kwargs = {}
+        if isinstance(params, dict):
+            kwargs['params'] = params
+        if save_to:
+            kwargs['stream'] = True
+
+        url = f'{self.endpoint}/{method}'
+        self.logger.debug(f'calling {url}, kwargs: {kwargs}')
+
+        r = requests.get(url, **kwargs)
+        if r.status_code != 200:
+            response = r.json()
+            raise ApiResponseError(status_code=r.status_code,
+                                   error_type=response['error'],
+                                   error_message=response['message'] or None,
+                                   error_stacktrace=response['stacktrace'] if 'stacktrace' in response else None)
+
+        if save_to:
+            r.raise_for_status()
+            with open(save_to, 'wb') as f:
+                shutil.copyfileobj(r.raw, f)
+            return True
+
+        return r.json()['response']
+
+
+class SoundNodeClient(MediaNodeClient):
+    def amixer_get_all(self):
+        return self._call('amixer/get-all/')
+
+    def amixer_get(self, control: str):
+        return self._call(f'amixer/get/{control}/')
+
+    def amixer_incr(self, control: str, step: Optional[int] = None):
+        params = {'step': step} if step is not None else None
+        return self._call(f'amixer/incr/{control}/', params=params)
+
+    def amixer_decr(self, control: str, step: Optional[int] = None):
+        params = {'step': step} if step is not None else None
+        return self._call(f'amixer/decr/{control}/', params=params)
+
+    def amixer_mute(self, control: str):
+        return self._call(f'amixer/mute/{control}/')
+
+    def amixer_unmute(self, control: str):
+        return self._call(f'amixer/unmute/{control}/')
+
+    def amixer_cap(self, control: str):
+        return self._call(f'amixer/cap/{control}/')
+
+    def amixer_nocap(self, control: str):
+        return self._call(f'amixer/nocap/{control}/')
+
+
+class CameraNodeClient(MediaNodeClient):
+    def capture(self,
+                save_to: str,
+                with_flash: bool = False):
+        return self._call('capture/',
+                          {'with_flash': int(with_flash)},
+                          save_to=save_to)
diff --git a/include/py/homekit/media/node_server.py b/include/py/homekit/media/node_server.py
new file mode 100644
index 0000000..5d0803c
--- /dev/null
+++ b/include/py/homekit/media/node_server.py
@@ -0,0 +1,86 @@
+from .. import http
+from .record import Recorder
+from .types import RecordStatus
+from .storage import RecordStorage
+
+
+class MediaNodeServer(http.HTTPServer):
+    recorder: Recorder
+    storage: RecordStorage
+
+    def __init__(self,
+                 recorder: Recorder,
+                 storage: RecordStorage,
+                 *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.recorder = recorder
+        self.storage = storage
+
+        self.get('/record/', self.do_record)
+        self.get('/record/info/{id}/', self.record_info)
+        self.get('/record/forget/{id}/', self.record_forget)
+        self.get('/record/download/{id}/', self.record_download)
+
+        self.get('/storage/list/', self.storage_list)
+        self.get('/storage/delete/', self.storage_delete)
+        self.get('/storage/download/', self.storage_download)
+
+    async def do_record(self, request: http.Request):
+        duration = int(request.query['duration'])
+        max = Recorder.get_max_record_time()*15
+        if not 0 < duration <= max:
+            raise ValueError(f'invalid duration: max duration is {max}')
+
+        record_id = self.recorder.record(duration)
+        return http.ok({'id': record_id})
+
+    async def record_info(self, request: http.Request):
+        record_id = int(request.match_info['id'])
+        info = self.recorder.get_info(record_id)
+        return http.ok(info.as_dict())
+
+    async def record_forget(self, request: http.Request):
+        record_id = int(request.match_info['id'])
+
+        info = self.recorder.get_info(record_id)
+        assert info.status in (RecordStatus.FINISHED, RecordStatus.ERROR), f"can't forget: record status is {info.status}"
+
+        self.recorder.forget(record_id)
+        return http.ok()
+
+    async def record_download(self, request: http.Request):
+        record_id = int(request.match_info['id'])
+
+        info = self.recorder.get_info(record_id)
+        assert info.status == RecordStatus.FINISHED, f"record status is {info.status}"
+
+        return http.FileResponse(info.file.path)
+
+    async def storage_list(self, request: http.Request):
+        extended = 'extended' in request.query and int(request.query['extended']) == 1
+
+        files = self.storage.getfiles(as_objects=extended)
+        if extended:
+            files = list(map(lambda file: file.__dict__(), files))
+
+        return http.ok({
+            'files': files
+        })
+
+    async def storage_delete(self, request: http.Request):
+        file_id = request.query['file_id']
+        file = self.storage.find(file_id)
+        if not file:
+            raise ValueError(f'file {file} not found')
+
+        self.storage.delete(file)
+        return http.ok()
+
+    async def storage_download(self, request):
+        file_id = request.query['file_id']
+        file = self.storage.find(file_id)
+        if not file:
+            raise ValueError(f'file {file} not found')
+
+        return http.FileResponse(file.path)
diff --git a/include/py/homekit/media/record.py b/include/py/homekit/media/record.py
new file mode 100644
index 0000000..cd7447a
--- /dev/null
+++ b/include/py/homekit/media/record.py
@@ -0,0 +1,461 @@
+import os
+import threading
+import logging
+import time
+import subprocess
+import signal
+
+from typing import Optional, List, Dict
+from ..util import find_child_processes, Addr
+from ..config import config
+from .storage import RecordFile, RecordStorage
+from .types import RecordStatus
+from ..camera.types import CameraType
+
+
+_history_item_timeout = 7200
+_history_cleanup_freq = 3600
+
+
+class RecordHistoryItem:
+    id: int
+    request_time: float
+    start_time: float
+    stop_time: float
+    relations: List[int]
+    status: RecordStatus
+    error: Optional[Exception]
+    file: Optional[RecordFile]
+    creation_time: float
+
+    def __init__(self, id):
+        self.id = id
+        self.request_time = 0
+        self.start_time = 0
+        self.stop_time = 0
+        self.relations = []
+        self.status = RecordStatus.WAITING
+        self.file = None
+        self.error = None
+        self.creation_time = time.time()
+
+    def add_relation(self, related_id: int):
+        self.relations.append(related_id)
+
+    def mark_started(self, start_time: float):
+        self.start_time = start_time
+        self.status = RecordStatus.RECORDING
+
+    def mark_finished(self, end_time: float, file: RecordFile):
+        self.stop_time = end_time
+        self.file = file
+        self.status = RecordStatus.FINISHED
+
+    def mark_failed(self, error: Exception):
+        self.status = RecordStatus.ERROR
+        self.error = error
+
+    def as_dict(self) -> dict:
+        data = {
+            'id': self.id,
+            'request_time': self.request_time,
+            'status': self.status.value,
+            'relations': self.relations,
+            'start_time': self.start_time,
+            'stop_time': self.stop_time,
+        }
+        if self.error:
+            data['error'] = str(self.error)
+        if self.file:
+            data['file'] = self.file.__dict__()
+        return data
+
+
+class RecordingNotFoundError(Exception):
+    pass
+
+
+class RecordHistory:
+    history: Dict[int, RecordHistoryItem]
+
+    def __init__(self):
+        self.history = {}
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+    def add(self, record_id: int):
+        self.logger.debug(f'add: record_id={record_id}')
+
+        r = RecordHistoryItem(record_id)
+        r.request_time = time.time()
+
+        self.history[record_id] = r
+
+    def delete(self, record_id: int):
+        self.logger.debug(f'delete: record_id={record_id}')
+        del self.history[record_id]
+
+    def cleanup(self):
+        del_ids = []
+        for rid, item in self.history.items():
+            if item.creation_time < time.time()-_history_item_timeout:
+                del_ids.append(rid)
+        for rid in del_ids:
+            self.delete(rid)
+
+    def __getitem__(self, key):
+        if key not in self.history:
+            raise RecordingNotFoundError()
+
+        return self.history[key]
+
+    def __setitem__(self, key, value):
+        raise NotImplementedError('setting history item this way is prohibited')
+
+    def __contains__(self, key):
+        return key in self.history
+
+
+class Recording:
+    RECORDER_PROGRAM = None
+
+    start_time: float
+    stop_time: float
+    duration: int
+    record_id: int
+    recorder_program_pid: Optional[int]
+    process: Optional[subprocess.Popen]
+
+    g_record_id = 1
+
+    def __init__(self):
+        if self.RECORDER_PROGRAM is None:
+            raise RuntimeError('this is abstract class')
+
+        self.start_time = 0
+        self.stop_time = 0
+        self.duration = 0
+        self.process = None
+        self.recorder_program_pid = None
+        self.record_id = Recording.next_id()
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+    def is_started(self) -> bool:
+        return self.start_time > 0 and self.stop_time > 0
+
+    def is_waiting(self):
+        return self.duration > 0
+
+    def ask_for(self, duration) -> int:
+        overtime = 0
+        orig_duration = duration
+
+        if self.is_started():
+            already_passed = time.time() - self.start_time
+            max_duration = Recorder.get_max_record_time() - already_passed
+            self.logger.debug(f'ask_for({orig_duration}): recording is in progress, already passed {already_passed}s, max_duration set to {max_duration}')
+        else:
+            max_duration = Recorder.get_max_record_time()
+
+        if duration > max_duration:
+            overtime = duration - max_duration
+            duration = max_duration
+
+            self.logger.debug(f'ask_for({orig_duration}): requested duration ({orig_duration}) is greater than max ({max_duration}), overtime is {overtime}')
+
+        self.duration += duration
+        if self.is_started():
+            til_end = self.stop_time - time.time()
+            if til_end < 0:
+                til_end = 0
+
+            _prev_stop_time = self.stop_time
+            _to_add = duration - til_end
+            if _to_add < 0:
+                _to_add = 0
+
+            self.stop_time += _to_add
+            self.logger.debug(f'ask_for({orig_duration}): adding {_to_add} to stop_time (before: {_prev_stop_time}, after: {self.stop_time})')
+
+        return overtime
+
+    def start(self, output: str):
+        assert self.start_time == 0 and self.stop_time == 0, "already started?!"
+        assert self.process is None, "self.process is not None, what the hell?"
+
+        cur = time.time()
+        self.start_time = cur
+        self.stop_time = cur + self.duration
+
+        cmd = self.get_command(output)
+        self.logger.debug(f'start: running `{cmd}`')
+        self.process = subprocess.Popen(cmd, shell=True, stdin=None, stdout=None, stderr=None, close_fds=True)
+
+        sh_pid = self.process.pid
+        self.logger.debug(f'start: started, pid of shell is {sh_pid}')
+
+        pid = self.find_recorder_program_pid(sh_pid)
+        if pid is not None:
+            self.recorder_program_pid = pid
+            self.logger.debug(f'start: pid of {self.RECORDER_PROGRAM} is {pid}')
+
+    def get_command(self, output: str) -> str:
+        pass
+
+    def stop(self):
+        if self.process:
+            if self.recorder_program_pid is None:
+                self.recorder_program_pid = self.find_recorder_program_pid(self.process.pid)
+
+            if self.recorder_program_pid is not None:
+                os.kill(self.recorder_program_pid, signal.SIGINT)
+                timeout = config['node']['process_wait_timeout']
+
+                self.logger.debug(f'stop: sent SIGINT to {self.recorder_program_pid}. now waiting up to {timeout} seconds...')
+                try:
+                    self.process.wait(timeout=timeout)
+                except subprocess.TimeoutExpired:
+                    self.logger.warning(f'stop: wait({timeout}): timeout expired, killing it')
+                    try:
+                        os.kill(self.recorder_program_pid, signal.SIGKILL)
+                        self.process.terminate()
+                    except Exception as exc:
+                        self.logger.exception(exc)
+            else:
+                self.logger.warning(f'stop: pid of {self.RECORDER_PROGRAM} is unknown, calling terminate()')
+                self.process.terminate()
+
+            rc = self.process.returncode
+            self.logger.debug(f'stop: rc={rc}')
+
+            self.process = None
+            self.recorder_program_pid = 0
+
+        self.duration = 0
+        self.start_time = 0
+        self.stop_time = 0
+
+    def find_recorder_program_pid(self, sh_pid: int):
+        try:
+            children = find_child_processes(sh_pid)
+        except OSError as exc:
+            self.logger.warning(f'failed to find child process of {sh_pid}: ' + str(exc))
+            return None
+
+        for child in children:
+            if self.RECORDER_PROGRAM in child.cmd:
+                return child.pid
+
+        return None
+
+    @staticmethod
+    def next_id() -> int:
+        cur_id = Recording.g_record_id
+        Recording.g_record_id += 1
+        return cur_id
+
+    def increment_id(self):
+        self.record_id = Recording.next_id()
+
+
+class Recorder:
+    TEMP_NAME = None
+
+    interrupted: bool
+    lock: threading.Lock
+    history_lock: threading.Lock
+    recording: Optional[Recording]
+    overtime: int
+    history: RecordHistory
+    next_history_cleanup_time: float
+    storage: RecordStorage
+
+    def __init__(self,
+                 storage: RecordStorage,
+                 recording: Recording):
+        if self.TEMP_NAME is None:
+            raise RuntimeError('this is abstract class')
+
+        self.storage = storage
+        self.recording = recording
+        self.interrupted = False
+        self.lock = threading.Lock()
+        self.history_lock = threading.Lock()
+        self.overtime = 0
+        self.history = RecordHistory()
+        self.next_history_cleanup_time = 0
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+    def start_thread(self):
+        t = threading.Thread(target=self.loop)
+        t.daemon = True
+        t.start()
+
+    def loop(self) -> None:
+        tempname = os.path.join(self.storage.root, self.TEMP_NAME)
+
+        while not self.interrupted:
+            cur = time.time()
+            stopped = False
+            cur_record_id = None
+
+            if self.next_history_cleanup_time == 0:
+                self.next_history_cleanup_time = time.time() + _history_cleanup_freq
+            elif self.next_history_cleanup_time <= time.time():
+                self.logger.debug('loop: calling history.cleanup()')
+                try:
+                    self.history.cleanup()
+                except Exception as e:
+                    self.logger.error('loop: error while history.cleanup(): ' + str(e))
+                self.next_history_cleanup_time = time.time() + _history_cleanup_freq
+
+            with self.lock:
+                cur_record_id = self.recording.record_id
+                # self.logger.debug(f'cur_record_id={cur_record_id}')
+
+                if not self.recording.is_started():
+                    if self.recording.is_waiting():
+                        try:
+                            if os.path.exists(tempname):
+                                self.logger.warning(f'loop: going to start new recording, but {tempname} still exists, unlinking..')
+                                try:
+                                    os.unlink(tempname)
+                                except OSError as e:
+                                    self.logger.exception(e)
+                            self.recording.start(tempname)
+                            with self.history_lock:
+                                self.history[cur_record_id].mark_started(self.recording.start_time)
+                        except Exception as exc:
+                            self.logger.exception(exc)
+
+                            # there should not be any errors, but still..
+                            try:
+                                self.recording.stop()
+                            except Exception as exc:
+                                self.logger.exception(exc)
+
+                            with self.history_lock:
+                                self.history[cur_record_id].mark_failed(exc)
+
+                            self.logger.debug(f'loop: start exc path: calling increment_id()')
+                            self.recording.increment_id()
+                else:
+                    if cur >= self.recording.stop_time:
+                        try:
+                            start_time = self.recording.start_time
+                            stop_time = self.recording.stop_time
+                            self.recording.stop()
+
+                            saved_name = self.storage.save(tempname,
+                                                           record_id=cur_record_id,
+                                                           start_time=int(start_time),
+                                                           stop_time=int(stop_time))
+
+                            with self.history_lock:
+                                self.history[cur_record_id].mark_finished(stop_time, saved_name)
+                        except Exception as exc:
+                            self.logger.exception(exc)
+                            with self.history_lock:
+                                self.history[cur_record_id].mark_failed(exc)
+                        finally:
+                            self.logger.debug(f'loop: stop exc final path: calling increment_id()')
+                            self.recording.increment_id()
+
+                        stopped = True
+
+            if stopped and self.overtime > 0:
+                self.logger.info(f'recording {cur_record_id} is stopped, but we\'ve got overtime ({self.overtime})')
+                _overtime = self.overtime
+                self.overtime = 0
+
+                related_id = self.record(_overtime)
+                self.logger.info(f'enqueued another record with id {related_id}')
+
+                if cur_record_id is not None:
+                    with self.history_lock:
+                        self.history[cur_record_id].add_relation(related_id)
+
+            time.sleep(0.2)
+
+    def record(self, duration: int) -> int:
+        self.logger.debug(f'record: duration={duration}')
+        with self.lock:
+            overtime = self.recording.ask_for(duration)
+            self.logger.debug(f'overtime={overtime}')
+
+            if overtime > self.overtime:
+                self.overtime = overtime
+
+            if not self.recording.is_started():
+                with self.history_lock:
+                    self.history.add(self.recording.record_id)
+
+            return self.recording.record_id
+
+    def stop(self):
+        self.interrupted = True
+
+    def get_info(self, record_id: int) -> RecordHistoryItem:
+        with self.history_lock:
+            return self.history[record_id]
+
+    def forget(self, record_id: int):
+        with self.history_lock:
+            self.logger.info(f'forget: removing record {record_id} from history')
+            self.history.delete(record_id)
+
+    @staticmethod
+    def get_max_record_time() -> int:
+        return config['node']['record_max_time']
+
+
+class SoundRecorder(Recorder):
+    TEMP_NAME = 'temp.mp3'
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(recording=SoundRecording(),
+                         *args, **kwargs)
+
+
+class CameraRecorder(Recorder):
+    TEMP_NAME = 'temp.mp4'
+
+    def __init__(self,
+                 camera_type: CameraType,
+                 *args, **kwargs):
+        if camera_type == CameraType.ESP32:
+            recording = ESP32CameraRecording(stream_addr=kwargs['stream_addr'])
+            del kwargs['stream_addr']
+        else:
+            raise RuntimeError(f'unsupported camera type {camera_type}')
+
+        super().__init__(recording=recording,
+                         *args, **kwargs)
+
+
+class SoundRecording(Recording):
+    RECORDER_PROGRAM = 'arecord'
+
+    def get_command(self, output: str) -> str:
+        arecord = config['arecord']['bin']
+        lame = config['lame']['bin']
+        b = config['lame']['bitrate']
+
+        return f'{arecord} -f S16 -r 44100 -t raw 2>/dev/null | {lame} -r -s 44.1 -b {b} -m m - {output} >/dev/null 2>/dev/null'
+
+
+class ESP32CameraRecording(Recording):
+    RECORDER_PROGRAM = 'esp32_capture.py'
+
+    stream_addr: Addr
+
+    def __init__(self, stream_addr: Addr):
+        super().__init__()
+        self.stream_addr = stream_addr
+
+    def get_command(self, output: str) -> str:
+        bin = config['esp32_capture']['bin']
+        return f'{bin} --addr {self.stream_addr[0]}:{self.stream_addr[1]} --output-directory {output} >/dev/null 2>/dev/null'
+
+    def start(self, output: str):
+        output = os.path.dirname(output)
+        return super().start(output)
\ No newline at end of file
diff --git a/include/py/homekit/media/record_client.py b/include/py/homekit/media/record_client.py
new file mode 100644
index 0000000..322495c
--- /dev/null
+++ b/include/py/homekit/media/record_client.py
@@ -0,0 +1,166 @@
+import time
+import logging
+import threading
+import os.path
+
+from tempfile import gettempdir
+from .record import RecordStatus
+from .node_client import SoundNodeClient, MediaNodeClient, CameraNodeClient
+from ..util import Addr
+from typing import Optional, Callable, Dict
+
+
+class RecordClient:
+    DOWNLOAD_EXTENSION = None
+
+    interrupted: bool
+    logger: logging.Logger
+    clients: Dict[str, MediaNodeClient]
+    awaiting: Dict[str, Dict[int, Optional[dict]]]
+    error_handler: Optional[Callable]
+    finished_handler: Optional[Callable]
+    download_on_finish: bool
+
+    def __init__(self,
+                 nodes: Dict[str, Addr],
+                 error_handler: Optional[Callable] = None,
+                 finished_handler: Optional[Callable] = None,
+                 download_on_finish=False):
+        if self.DOWNLOAD_EXTENSION is None:
+            raise RuntimeError('this is abstract class')
+
+        self.interrupted = False
+        self.logger = logging.getLogger(self.__class__.__name__)
+        self.clients = {}
+        self.awaiting = {}
+
+        self.download_on_finish = download_on_finish
+        self.error_handler = error_handler
+        self.finished_handler = finished_handler
+
+        self.awaiting_lock = threading.Lock()
+
+        self.make_clients(nodes)
+
+        try:
+            t = threading.Thread(target=self.loop)
+            t.daemon = True
+            t.start()
+        except (KeyboardInterrupt, SystemExit) as exc:
+            self.stop()
+            self.logger.exception(exc)
+
+    def make_clients(self, nodes: Dict[str, Addr]):
+        pass
+
+    def stop(self):
+        self.interrupted = True
+
+    def loop(self):
+        while not self.interrupted:
+            for node in self.awaiting.keys():
+                with self.awaiting_lock:
+                    record_ids = list(self.awaiting[node].keys())
+                if not record_ids:
+                    continue
+
+                self.logger.debug(f'loop: node `{node}` awaiting list: {record_ids}')
+
+                cl = self.getclient(node)
+                del_ids = []
+                for rid in record_ids:
+                    info = cl.record_info(rid)
+
+                    if info['relations']:
+                        for relid in info['relations']:
+                            self.wait_for_record(node, relid, self.awaiting[node][rid], is_relative=True)
+
+                    status = RecordStatus(info['status'])
+                    if status in (RecordStatus.FINISHED, RecordStatus.ERROR):
+                        if status == RecordStatus.FINISHED:
+                            if self.download_on_finish:
+                                local_fn = self.download(node, rid, info['file']['fileid'])
+                            else:
+                                local_fn = None
+                            self._report_finished(info, local_fn, self.awaiting[node][rid])
+                        else:
+                            self._report_error(info, self.awaiting[node][rid])
+                        del_ids.append(rid)
+                        self.logger.debug(f'record {rid}: status {status}')
+
+                if del_ids:
+                    self.logger.debug(f'deleting {del_ids} from {node}\'s awaiting list')
+                    with self.awaiting_lock:
+                        for del_id in del_ids:
+                            del self.awaiting[node][del_id]
+
+            time.sleep(5)
+
+        self.logger.info('loop ended')
+
+    def getclient(self, node: str):
+        return self.clients[node]
+
+    def record(self,
+               node: str,
+               duration: int,
+               userdata: Optional[dict] = None) -> int:
+        self.logger.debug(f'record: node={node}, duration={duration}, userdata={userdata}')
+
+        cl = self.getclient(node)
+        record_id = cl.record(duration)['id']
+        self.logger.debug(f'record: request sent, record_id={record_id}')
+
+        self.wait_for_record(node, record_id, userdata)
+        return record_id
+
+    def wait_for_record(self,
+                        node: str,
+                        record_id: int,
+                        userdata: Optional[dict] = None,
+                        is_relative=False):
+        with self.awaiting_lock:
+            if record_id not in self.awaiting[node]:
+                msg = f'wait_for_record: adding {record_id} to {node}'
+                if is_relative:
+                    msg += ' (by relation)'
+                self.logger.debug(msg)
+
+                self.awaiting[node][record_id] = userdata
+
+    def download(self, node: str, record_id: int, fileid: str):
+        dst = os.path.join(gettempdir(), f'{node}_{fileid}.{self.DOWNLOAD_EXTENSION}')
+        cl = self.getclient(node)
+        cl.record_download(record_id, dst)
+        return dst
+
+    def forget(self, node: str, rid: int):
+        self.getclient(node).record_forget(rid)
+
+    def _report_finished(self, *args):
+        if self.finished_handler:
+            self.finished_handler(*args)
+
+    def _report_error(self, *args):
+        if self.error_handler:
+            self.error_handler(*args)
+
+
+class SoundRecordClient(RecordClient):
+    DOWNLOAD_EXTENSION = 'mp3'
+    # clients: Dict[str, SoundNodeClient]
+
+    def make_clients(self, nodes: Dict[str, Addr]):
+        for node, addr in nodes.items():
+            self.clients[node] = SoundNodeClient(addr)
+            self.awaiting[node] = {}
+
+
+class CameraRecordClient(RecordClient):
+    DOWNLOAD_EXTENSION = 'mp4'
+    # clients: Dict[str, CameraNodeClient]
+
+    def make_clients(self, nodes: Dict[str, Addr]):
+        for node, addr in nodes.items():
+            self.clients[node] = CameraNodeClient(addr)
+            self.awaiting[node] = {}
\ No newline at end of file
diff --git a/include/py/homekit/media/storage.py b/include/py/homekit/media/storage.py
new file mode 100644
index 0000000..dd74ff8
--- /dev/null
+++ b/include/py/homekit/media/storage.py
@@ -0,0 +1,210 @@
+import os
+import re
+import shutil
+import logging
+
+from typing import Optional, Union, List
+from datetime import datetime
+from ..util import strgen
+
+logger = logging.getLogger(__name__)
+
+
+# record file
+# -----------
+
+class RecordFile:
+    EXTENSION = None
+
+    start_time: Optional[datetime]
+    stop_time: Optional[datetime]
+    record_id: Optional[int]
+    name: str
+    file_id: Optional[str]
+    remote: bool
+    remote_filesize: int
+    storage_root: str
+
+    human_date_dmt = '%d.%m.%y'
+    human_time_fmt = '%H:%M:%S'
+
+    @staticmethod
+    def create(filename: str, *args, **kwargs):
+        if filename.endswith(f'.{SoundRecordFile.EXTENSION}'):
+            return SoundRecordFile(filename, *args, **kwargs)
+        elif filename.endswith(f'.{CameraRecordFile.EXTENSION}'):
+            return CameraRecordFile(filename, *args, **kwargs)
+        else:
+            raise RuntimeError(f'unsupported file extension: {filename}')
+
+    def __init__(self, filename: str, remote=False, remote_filesize=None, storage_root='/'):
+        if self.EXTENSION is None:
+            raise RuntimeError('this is abstract class')
+
+        self.name = filename
+        self.storage_root = storage_root
+
+        self.remote = remote
+        self.remote_filesize = remote_filesize
+
+        m = re.match(r'^(\d{6}-\d{6})_(\d{6}-\d{6})_id(\d+)(_\w+)?\.'+self.EXTENSION+'$', filename)
+        if m:
+            self.start_time = datetime.strptime(m.group(1), RecordStorage.time_fmt)
+            self.stop_time = datetime.strptime(m.group(2), RecordStorage.time_fmt)
+            self.record_id = int(m.group(3))
+            self.file_id = (m.group(1) + '_' + m.group(2)).replace('-', '_')
+        else:
+            logger.warning(f'unexpected filename: {filename}')
+            self.start_time = None
+            self.stop_time = None
+            self.record_id = None
+            self.file_id = None
+
+    @property
+    def path(self):
+        if self.remote:
+            return RuntimeError('remote recording, can\'t get real path')
+
+        return os.path.realpath(os.path.join(
+            self.storage_root, self.name
+        ))
+
+    @property
+    def start_humantime(self) -> str:
+        if self.start_time is None:
+            return '?'
+        fmt = f'{RecordFile.human_date_dmt} {RecordFile.human_time_fmt}'
+        return self.start_time.strftime(fmt)
+
+    @property
+    def stop_humantime(self) -> str:
+        if self.stop_time is None:
+            return '?'
+        fmt = RecordFile.human_time_fmt
+        if self.start_time.date() != self.stop_time.date():
+            fmt = f'{RecordFile.human_date_dmt} {fmt}'
+        return self.stop_time.strftime(fmt)
+
+    @property
+    def start_unixtime(self) -> int:
+        if self.start_time is None:
+            return 0
+        return int(self.start_time.timestamp())
+
+    @property
+    def stop_unixtime(self) -> int:
+        if self.stop_time is None:
+            return 0
+        return int(self.stop_time.timestamp())
+
+    @property
+    def filesize(self):
+        if self.remote:
+            if self.remote_filesize is None:
+                raise RuntimeError('file is remote and remote_filesize is not set')
+            return self.remote_filesize
+        return os.path.getsize(self.path)
+
+    def __dict__(self) -> dict:
+        return {
+            'start_unixtime': self.start_unixtime,
+            'stop_unixtime': self.stop_unixtime,
+            'filename': self.name,
+            'filesize': self.filesize,
+            'fileid': self.file_id,
+            'record_id': self.record_id or 0,
+        }
+
+
+class PseudoRecordFile(RecordFile):
+    EXTENSION = 'null'
+
+    def __init__(self):
+        super().__init__('pseudo.null')
+
+    @property
+    def filesize(self):
+        return 0
+
+
+class SoundRecordFile(RecordFile):
+    EXTENSION = 'mp3'
+
+
+class CameraRecordFile(RecordFile):
+    EXTENSION = 'mp4'
+
+
+# record storage
+# --------------
+
+class RecordStorage:
+    EXTENSION = None
+
+    time_fmt = '%d%m%y-%H%M%S'
+
+    def __init__(self, root: str):
+        if self.EXTENSION is None:
+            raise RuntimeError('this is abstract class')
+
+        self.root = root
+
+    def getfiles(self, as_objects=False) -> Union[List[str], List[RecordFile]]:
+        files = []
+        for name in os.listdir(self.root):
+            path = os.path.join(self.root, name)
+            if os.path.isfile(path) and name.endswith(f'.{self.EXTENSION}'):
+                files.append(name if not as_objects else RecordFile.create(name, storage_root=self.root))
+        return files
+
+    def find(self, file_id: str) -> Optional[RecordFile]:
+        for name in os.listdir(self.root):
+            if os.path.isfile(os.path.join(self.root, name)) and name.endswith(f'.{self.EXTENSION}'):
+                item = RecordFile.create(name, storage_root=self.root)
+                if item.file_id == file_id:
+                    return item
+        return None
+
+    def purge(self):
+        files = self.getfiles()
+        if files:
+            logger = logging.getLogger(self.__name__)
+            for f in files:
+                try:
+                    path = os.path.join(self.root, f)
+                    logger.debug(f'purge: deleting {path}')
+                    os.unlink(path)
+                except OSError as exc:
+                    logger.exception(exc)
+
+    def delete(self, file: RecordFile):
+        os.unlink(file.path)
+
+    def save(self,
+             fn: str,
+             record_id: int,
+             start_time: int,
+             stop_time: int) -> RecordFile:
+
+        start_time_s = datetime.fromtimestamp(start_time).strftime(self.time_fmt)
+        stop_time_s = datetime.fromtimestamp(stop_time).strftime(self.time_fmt)
+
+        dst_fn = f'{start_time_s}_{stop_time_s}_id{record_id}'
+        if os.path.exists(os.path.join(self.root, dst_fn)):
+            dst_fn += strgen(4)
+        dst_fn += f'.{self.EXTENSION}'
+        dst_path = os.path.join(self.root, dst_fn)
+
+        shutil.move(fn, dst_path)
+        return RecordFile.create(dst_fn, storage_root=self.root)
+
+
+class SoundRecordStorage(RecordStorage):
+    EXTENSION = 'mp3'
+
+
+class ESP32CameraRecordStorage(RecordStorage):
+    EXTENSION = 'jpg'  # not used anyway
+
+    def save(self, *args, **kwargs):
+        return PseudoRecordFile()
\ No newline at end of file
diff --git a/include/py/homekit/media/types.py b/include/py/homekit/media/types.py
new file mode 100644
index 0000000..acbc291
--- /dev/null
+++ b/include/py/homekit/media/types.py
@@ -0,0 +1,13 @@
+from enum import Enum, auto
+
+
+class MediaNodeType(Enum):
+    SOUND = auto()
+    CAMERA = auto()
+
+
+class RecordStatus(Enum):
+    WAITING = auto()
+    RECORDING = auto()
+    FINISHED = auto()
+    ERROR = auto()
diff --git a/include/py/homekit/mqtt/__init__.py b/include/py/homekit/mqtt/__init__.py
new file mode 100644
index 0000000..707d59c
--- /dev/null
+++ b/include/py/homekit/mqtt/__init__.py
@@ -0,0 +1,7 @@
+from ._mqtt import Mqtt
+from ._node import MqttNode
+from ._module import MqttModule
+from ._wrapper import MqttWrapper
+from ._config import MqttConfig, MqttCreds, MqttNodesConfig
+from ._payload import MqttPayload, MqttPayloadCustomField
+from ._util import get_modules as get_mqtt_modules
\ No newline at end of file
diff --git a/include/py/homekit/mqtt/_config.py b/include/py/homekit/mqtt/_config.py
new file mode 100644
index 0000000..9ba9443
--- /dev/null
+++ b/include/py/homekit/mqtt/_config.py
@@ -0,0 +1,165 @@
+from ..config import ConfigUnit
+from typing import Optional, Union
+from ..util import Addr
+from collections import namedtuple
+
+MqttCreds = namedtuple('MqttCreds', 'username, password')
+
+
+class MqttConfig(ConfigUnit):
+    NAME = 'mqtt'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        addr_schema = {
+            'type': 'dict',
+            'required': True,
+            'schema': {
+                'host': {'type': 'string', 'required': True},
+                'port': {'type': 'integer', 'required': True}
+            }
+        }
+
+        schema = {}
+        for key in ('local', 'remote'):
+            schema[f'{key}_addr'] = addr_schema
+
+        schema['creds'] = {
+            'type': 'dict',
+            'required': True,
+            'keysrules': {'type': 'string'},
+            'valuesrules': {
+                'type': 'dict',
+                'schema': {
+                    'username': {'type': 'string', 'required': True},
+                    'password': {'type': 'string', 'required': True},
+                }
+            }
+        }
+
+        for key in ('client', 'server'):
+            schema[f'default_{key}_creds'] = {'type': 'string', 'required': True}
+
+        return schema
+
+    def remote_addr(self) -> Addr:
+        return Addr(host=self['remote_addr']['host'],
+                    port=self['remote_addr']['port'])
+
+    def local_addr(self) -> Addr:
+        return Addr(host=self['local_addr']['host'],
+                    port=self['local_addr']['port'])
+
+    def creds_by_name(self, name: str) -> MqttCreds:
+        return MqttCreds(username=self['creds'][name]['username'],
+                         password=self['creds'][name]['password'])
+
+    def creds(self) -> MqttCreds:
+        return self.creds_by_name(self['default_client_creds'])
+
+    def server_creds(self) -> MqttCreds:
+        return self.creds_by_name(self['default_server_creds'])
+
+
+class MqttNodesConfig(ConfigUnit):
+    NAME = 'mqtt_nodes'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'common': {
+                'type': 'dict',
+                'schema': {
+                    'temphum': {
+                        'type': 'dict',
+                        'schema': {
+                            'interval': {'type': 'integer'}
+                        }
+                    },
+                    'password': {'type': 'string'}
+                }
+            },
+            'nodes': {
+                'type': 'dict',
+                'required': True,
+                'keysrules': {'type': 'string'},
+                'valuesrules': {
+                    'type': 'dict',
+                    'schema': {
+                        'type': {'type': 'string', 'required': True, 'allowed': ['esp8266', 'linux', 'none'],},
+                        'board': {'type': 'string', 'allowed': ['nodemcu', 'd1_mini_lite', 'esp12e']},
+                        'temphum': {
+                            'type': 'dict',
+                            'schema': {
+                                'module': {'type': 'string', 'required': True, 'allowed': ['si7021', 'dht12']},
+                                'interval': {'type': 'integer'},
+                                'i2c_bus': {'type': 'integer'},
+                                'tcpserver': {
+                                    'type': 'dict',
+                                    'schema': {
+                                        'port': {'type': 'integer', 'required': True}
+                                    }
+                                }
+                            }
+                        },
+                        'relay': {
+                            'type': 'dict',
+                            'schema': {
+                                'device_type': {'type': 'string', 'allowed': ['lamp', 'pump', 'solenoid'], 'required': True},
+                                'legacy_topics': {'type': 'boolean'}
+                            }
+                        },
+                        'password': {'type': 'string'}
+                    }
+                }
+            }
+        }
+
+    @staticmethod
+    def custom_validator(data):
+        for name, node in data['nodes'].items():
+            if 'temphum' in node:
+                if node['type'] == 'linux':
+                    if 'i2c_bus' not in node['temphum']:
+                        raise KeyError(f'nodes.{name}.temphum: i2c_bus is missing but required for type=linux')
+            if node['type'] in ('esp8266',) and 'board' not in node:
+                raise KeyError(f'nodes.{name}: board is missing but required for type={node["type"]}')
+
+    def get_node(self, name: str) -> dict:
+        node = self['nodes'][name]
+        if node['type'] == 'none':
+            return node
+
+        try:
+            if 'password' not in node:
+                node['password'] = self['common']['password']
+        except KeyError:
+            pass
+
+        try:
+            if 'temphum' in node:
+                for ckey, cval in self['common']['temphum'].items():
+                    if ckey not in node['temphum']:
+                        node['temphum'][ckey] = cval
+        except KeyError:
+            pass
+
+        return node
+
+    def get_nodes(self,
+                  filters: Optional[Union[list[str], tuple[str]]] = None,
+                  only_names=False) -> Union[dict, list[str]]:
+        if filters:
+            for f in filters:
+                if f not in ('temphum', 'relay'):
+                    raise ValueError(f'{self.__class__.__name__}::get_node(): invalid filter {f}')
+        reslist = []
+        resdict = {}
+        for name in self['nodes'].keys():
+            node = self.get_node(name)
+            if (not filters) or ('temphum' in filters and 'temphum' in node) or ('relay' in filters and 'relay' in node):
+                if only_names:
+                    reslist.append(name)
+                else:
+                    resdict[name] = node
+        return reslist if only_names else resdict
diff --git a/include/py/homekit/mqtt/_module.py b/include/py/homekit/mqtt/_module.py
new file mode 100644
index 0000000..80f27bb
--- /dev/null
+++ b/include/py/homekit/mqtt/_module.py
@@ -0,0 +1,70 @@
+from __future__ import annotations
+
+import abc
+import logging
+import threading
+
+from time import sleep
+from ..util import next_tick_gen
+
+from typing import TYPE_CHECKING, Optional
+if TYPE_CHECKING:
+    from ._node import MqttNode
+    from ._payload import MqttPayload
+
+
+class MqttModule(abc.ABC):
+    _tick_interval: int
+    _initialized: bool
+    _connected: bool
+    _ticker: Optional[threading.Thread]
+    _mqtt_node_ref: Optional[MqttNode]
+
+    def __init__(self, tick_interval=0):
+        self._tick_interval = tick_interval
+        self._initialized = False
+        self._ticker = None
+        self._logger = logging.getLogger(self.__class__.__name__)
+        self._connected = False
+        self._mqtt_node_ref = None
+
+    def on_connect(self, mqtt: MqttNode):
+        self._connected = True
+        self._mqtt_node_ref = mqtt
+        if self._tick_interval:
+            self._start_ticker()
+
+    def on_disconnect(self, mqtt: MqttNode):
+        self._connected = False
+        self._mqtt_node_ref = None
+
+    def is_initialized(self):
+        return self._initialized
+
+    def set_initialized(self):
+        self._initialized = True
+
+    def unset_initialized(self):
+        self._initialized = False
+
+    def tick(self):
+        pass
+
+    def _tick(self):
+        g = next_tick_gen(self._tick_interval)
+        while self._connected:
+            sleep(next(g))
+            if not self._connected:
+                break
+            self.tick()
+
+    def _start_ticker(self):
+        if not self._ticker or not self._ticker.is_alive():
+            name_part = f'{self._mqtt_node_ref.id}/' if self._mqtt_node_ref else ''
+            self._ticker = None
+            self._ticker = threading.Thread(target=self._tick,
+                                            name=f'mqtt:{self.__class__.__name__}/{name_part}ticker')
+            self._ticker.start()
+
+    def handle_payload(self, mqtt: MqttNode, topic: str, payload: bytes) -> Optional[MqttPayload]:
+        pass
diff --git a/include/py/homekit/mqtt/_mqtt.py b/include/py/homekit/mqtt/_mqtt.py
new file mode 100644
index 0000000..fb35a24
--- /dev/null
+++ b/include/py/homekit/mqtt/_mqtt.py
@@ -0,0 +1,86 @@
+import os.path
+import paho.mqtt.client as mqtt
+import ssl
+import logging
+
+from ._config import MqttCreds, MqttConfig
+from typing import Optional
+
+
+class Mqtt:
+    _connected: bool
+    _is_server: bool
+    _mqtt_config: MqttConfig
+
+    def __init__(self,
+                 clean_session=True,
+                 client_id='',
+                 creds: Optional[MqttCreds] = None,
+                 is_server=False):
+        if not client_id:
+            raise ValueError('client_id must not be empty')
+
+        self._client = mqtt.Client(client_id=client_id,
+                                   protocol=mqtt.MQTTv311,
+                                   clean_session=clean_session)
+        self._client.on_connect = self.on_connect
+        self._client.on_disconnect = self.on_disconnect
+        self._client.on_message = self.on_message
+        self._client.on_log = self.on_log
+        self._client.on_publish = self.on_publish
+        self._loop_started = False
+        self._connected = False
+        self._is_server = is_server
+        self._mqtt_config = MqttConfig()
+        self._logger = logging.getLogger(self.__class__.__name__)
+
+        if not creds:
+            creds = self._mqtt_config.creds() if not is_server else self._mqtt_config.server_creds()
+
+        self._client.username_pw_set(creds.username, creds.password)
+
+    def _configure_tls(self):
+        ca_certs = os.path.realpath(os.path.join(
+            os.path.dirname(os.path.realpath(__file__)),
+            '..',
+            '..',
+            '..',
+            'misc',
+            'mqtt_ca.crt'
+        ))
+        self._client.tls_set(ca_certs=ca_certs,
+                             cert_reqs=ssl.CERT_REQUIRED,
+                             tls_version=ssl.PROTOCOL_TLSv1_2)
+
+    def connect_and_loop(self, loop_forever=True):
+        self._configure_tls()
+        addr = self._mqtt_config.local_addr() if self._is_server else self._mqtt_config.remote_addr()
+        self._client.connect(addr.host, addr.port, 60)
+        if loop_forever:
+            self._client.loop_forever()
+        else:
+            self._client.loop_start()
+            self._loop_started = True
+
+    def disconnect(self):
+        self._client.disconnect()
+        self._client.loop_write()
+        self._client.loop_stop()
+
+    def on_connect(self, client: mqtt.Client, userdata, flags, rc):
+        self._logger.info("Connected with result code " + str(rc))
+        self._connected = True
+
+    def on_disconnect(self, client: mqtt.Client, userdata, rc):
+        self._logger.info("Disconnected with result code " + str(rc))
+        self._connected = False
+
+    def on_log(self, client: mqtt.Client, userdata, level, buf):
+        level = mqtt.LOGGING_LEVEL[level] if level in mqtt.LOGGING_LEVEL else logging.INFO
+        self._logger.log(level, f'MQTT: {buf}')
+
+    def on_message(self, client: mqtt.Client, userdata, msg):
+        self._logger.debug(msg.topic + ": " + str(msg.payload))
+
+    def on_publish(self, client: mqtt.Client, userdata, mid):
+        self._logger.debug(f'publish done, mid={mid}')
diff --git a/include/py/homekit/mqtt/_node.py b/include/py/homekit/mqtt/_node.py
new file mode 100644
index 0000000..4e259a4
--- /dev/null
+++ b/include/py/homekit/mqtt/_node.py
@@ -0,0 +1,92 @@
+import logging
+import importlib
+
+from typing import List, TYPE_CHECKING, Optional
+from ._payload import MqttPayload
+from ._module import MqttModule
+if TYPE_CHECKING:
+    from ._wrapper import MqttWrapper
+else:
+    MqttWrapper = None
+
+
+class MqttNode:
+    _modules: List[MqttModule]
+    _module_subscriptions: dict[str, MqttModule]
+    _node_id: str
+    _node_secret: str
+    _payload_callbacks: list[callable]
+    _wrapper: Optional[MqttWrapper]
+
+    def __init__(self,
+                 node_id: str,
+                 node_secret: Optional[str] = None):
+        self._modules = []
+        self._module_subscriptions = {}
+        self._node_id = node_id
+        self._node_secret = node_secret
+        self._payload_callbacks = []
+        self._logger = logging.getLogger(self.__class__.__name__)
+        self._wrapper = None
+
+    def on_connect(self, wrapper: MqttWrapper):
+        self._wrapper = wrapper
+        for module in self._modules:
+            if not module.is_initialized():
+                module.on_connect(self)
+                module.set_initialized()
+
+    def on_disconnect(self):
+        self._wrapper = None
+        for module in self._modules:
+            module.unset_initialized()
+
+    def on_message(self, topic, payload):
+        if topic in self._module_subscriptions:
+            payload = self._module_subscriptions[topic].handle_payload(self, topic, payload)
+            if isinstance(payload, MqttPayload):
+                for f in self._payload_callbacks:
+                    f(self, payload)
+
+    def load_module(self, module_name: str, *args, **kwargs) -> MqttModule:
+        module = importlib.import_module(f'..module.{module_name}', __name__)
+        if not hasattr(module, 'MODULE_NAME'):
+            raise RuntimeError(f'MODULE_NAME not found in module {module}')
+        cl = getattr(module, getattr(module, 'MODULE_NAME'))
+        instance = cl(*args, **kwargs)
+        self.add_module(instance)
+        return instance
+
+    def add_module(self, module: MqttModule):
+        self._modules.append(module)
+        if self._wrapper and self._wrapper._connected:
+            module.on_connect(self)
+            module.set_initialized()
+
+    def subscribe_module(self, topic: str, module: MqttModule, qos: int = 1):
+        if not self._wrapper or not self._wrapper._connected:
+            raise RuntimeError('not connected')
+
+        self._module_subscriptions[topic] = module
+        self._wrapper.subscribe(self.id, topic, qos)
+
+    def publish(self,
+                topic: str,
+                payload: bytes,
+                qos: int = 1):
+        self._wrapper.publish(self.id, topic, payload, qos)
+
+    def add_payload_callback(self, callback: callable):
+        self._payload_callbacks.append(callback)
+
+    @property
+    def id(self) -> str:
+        return self._node_id
+
+    @property
+    def secret(self) -> str:
+        return self._node_secret
+
+    @secret.setter
+    def secret(self, secret: str) -> None:
+        self._node_secret = secret
diff --git a/include/py/homekit/mqtt/_payload.py b/include/py/homekit/mqtt/_payload.py
new file mode 100644
index 0000000..58eeae3
--- /dev/null
+++ b/include/py/homekit/mqtt/_payload.py
@@ -0,0 +1,145 @@
+import struct
+import abc
+import re
+
+from typing import Optional, Tuple
+
+
+def pldstr(self) -> str:
+    attrs = []
+    for field in self.__class__.__annotations__:
+        if hasattr(self, field):
+            attr = getattr(self, field)
+            attrs.append(f'{field}={attr}')
+    if attrs:
+        attrs_s = ' '
+        attrs_s += ', '.join(attrs)
+    else:
+        attrs_s = ''
+    return f'<%s{attrs_s}>' % (self.__class__.__name__,)
+
+
+class MqttPayload(abc.ABC):
+    FORMAT = ''
+    PACKER = {}
+    UNPACKER = {}
+
+    def __init__(self, **kwargs):
+        for field in self.__class__.__annotations__:
+            setattr(self, field, kwargs[field])
+
+    def pack(self):
+        args = []
+        bf_number = -1
+        bf_arg = 0
+        bf_progress = 0
+
+        for field, field_type in self.__class__.__annotations__.items():
+            bfp = _bit_field_params(field_type)
+            if bfp:
+                n, s, b = bfp
+                if n != bf_number:
+                    if bf_number != -1:
+                        args.append(bf_arg)
+                    bf_number = n
+                    bf_progress = 0
+                    bf_arg = 0
+                bf_arg |= (getattr(self, field) & (2 ** b - 1)) << bf_progress
+                bf_progress += b
+
+            else:
+                if bf_number != -1:
+                    args.append(bf_arg)
+                    bf_number = -1
+                    bf_progress = 0
+                    bf_arg = 0
+
+                args.append(self._pack_field(field))
+
+        if bf_number != -1:
+            args.append(bf_arg)
+
+        return struct.pack(self.FORMAT, *args)
+
+    @classmethod
+    def unpack(cls, buf: bytes):
+        data = struct.unpack(cls.FORMAT, buf)
+        kwargs = {}
+        i = 0
+        bf_number = -1
+        bf_progress = 0
+
+        for field, field_type in cls.__annotations__.items():
+            bfp = _bit_field_params(field_type)
+            if bfp:
+                n, s, b = bfp
+                if n != bf_number:
+                    bf_number = n
+                    bf_progress = 0
+                kwargs[field] = (data[i] >> bf_progress) & (2 ** b - 1)
+                bf_progress += b
+                continue  # don't increment i
+
+            if bf_number != -1:
+                bf_number = -1
+                i += 1
+
+            if issubclass(field_type, MqttPayloadCustomField):
+                kwargs[field] = field_type.unpack(data[i])
+            else:
+                kwargs[field] = cls._unpack_field(field, data[i])
+            i += 1
+
+        return cls(**kwargs)
+
+    def _pack_field(self, name):
+        val = getattr(self, name)
+        if self.PACKER and name in self.PACKER:
+            return self.PACKER[name](val)
+        else:
+            return val
+
+    @classmethod
+    def _unpack_field(cls, name, val):
+        if isinstance(val, MqttPayloadCustomField):
+            return
+        if cls.UNPACKER and name in cls.UNPACKER:
+            return cls.UNPACKER[name](val)
+        else:
+            return val
+
+    def __str__(self):
+        return pldstr(self)
+
+
+class MqttPayloadCustomField(abc.ABC):
+    def __init__(self, **kwargs):
+        for field in self.__class__.__annotations__:
+            setattr(self, field, kwargs[field])
+
+    @abc.abstractmethod
+    def __index__(self):
+        pass
+
+    @classmethod
+    @abc.abstractmethod
+    def unpack(cls, *args, **kwargs):
+        pass
+
+    def __str__(self):
+        return pldstr(self)
+
+
+def bit_field(seq_no: int, total_bits: int, bits: int):
+    return type(f'MQTTPayloadBitField_{seq_no}_{total_bits}_{bits}', (object,), {
+        'seq_no': seq_no,
+        'total_bits': total_bits,
+        'bits': bits
+    })
+
+
+def _bit_field_params(cl) -> Optional[Tuple[int, ...]]:
+    match = re.match(r'MQTTPayloadBitField_(\d+)_(\d+)_(\d)$', cl.__name__)
+    if match is not None:
+        return tuple([int(match.group(i)) for i in range(1, 4)])
+    return None
\ No newline at end of file
diff --git a/include/py/homekit/mqtt/_util.py b/include/py/homekit/mqtt/_util.py
new file mode 100644
index 0000000..390d463
--- /dev/null
+++ b/include/py/homekit/mqtt/_util.py
@@ -0,0 +1,15 @@
+import os
+import re
+
+from typing import List
+
+
+def get_modules() -> List[str]:
+    modules = []
+    modules_dir = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'module')
+    for name in os.listdir(modules_dir):
+        if os.path.isdir(os.path.join(modules_dir, name)):
+            continue
+        name = re.sub(r'\.py$', '', name)
+        modules.append(name)
+    return modules
diff --git a/include/py/homekit/mqtt/_wrapper.py b/include/py/homekit/mqtt/_wrapper.py
new file mode 100644
index 0000000..3c2774c
--- /dev/null
+++ b/include/py/homekit/mqtt/_wrapper.py
@@ -0,0 +1,60 @@
+import paho.mqtt.client as mqtt
+
+from ._mqtt import Mqtt
+from ._node import MqttNode
+from ..util import strgen
+
+
+class MqttWrapper(Mqtt):
+    _nodes: list[MqttNode]
+
+    def __init__(self,
+                 client_id: str,
+                 topic_prefix='hk',
+                 randomize_client_id=False,
+                 clean_session=True):
+        if randomize_client_id:
+            client_id += '_'+strgen(6)
+        super().__init__(clean_session=clean_session,
+                         client_id=client_id)
+        self._nodes = []
+        self._topic_prefix = topic_prefix
+
+    def on_connect(self, client: mqtt.Client, userdata, flags, rc):
+        super().on_connect(client, userdata, flags, rc)
+        for node in self._nodes:
+            node.on_connect(self)
+
+    def on_disconnect(self, client: mqtt.Client, userdata, rc):
+        super().on_disconnect(client, userdata, rc)
+        for node in self._nodes:
+            node.on_disconnect()
+
+    def on_message(self, client: mqtt.Client, userdata, msg):
+        try:
+            topic = msg.topic
+            topic_node = topic[len(self._topic_prefix)+1:topic.find('/', len(self._topic_prefix)+1)]
+            for node in self._nodes:
+                if node.id in ('+', topic_node):
+                    node.on_message(topic[len(f'{self._topic_prefix}/{node.id}/'):], msg.payload)
+        except Exception as e:
+            self._logger.exception(str(e))
+
+    def add_node(self, node: MqttNode):
+        self._nodes.append(node)
+        if self._connected:
+            node.on_connect(self)
+
+    def subscribe(self,
+                  node_id: str,
+                  topic: str,
+                  qos: int):
+        self._client.subscribe(f'{self._topic_prefix}/{node_id}/{topic}', qos)
+
+    def publish(self,
+                node_id: str,
+                topic: str,
+                payload: bytes,
+                qos: int):
+        self._client.publish(f'{self._topic_prefix}/{node_id}/{topic}', payload, qos)
+        self._client.loop_write()
diff --git a/include/py/homekit/mqtt/module/diagnostics.py b/include/py/homekit/mqtt/module/diagnostics.py
new file mode 100644
index 0000000..5db5e99
--- /dev/null
+++ b/include/py/homekit/mqtt/module/diagnostics.py
@@ -0,0 +1,64 @@
+from .._payload import MqttPayload, MqttPayloadCustomField
+from .._node import MqttNode, MqttModule
+from typing import Optional
+
+MODULE_NAME = 'MqttDiagnosticsModule'
+
+
+class DiagnosticsFlags(MqttPayloadCustomField):
+    state: bool
+    config_changed_value_present: bool
+    config_changed: bool
+
+    @staticmethod
+    def unpack(flags: int):
+        # _logger.debug(f'StatFlags.unpack: flags={flags}')
+        state = flags & 0x1
+        ccvp = (flags >> 1) & 0x1
+        cc = (flags >> 2) & 0x1
+        # _logger.debug(f'StatFlags.unpack: state={state}')
+        return DiagnosticsFlags(state=(state == 1),
+                                config_changed_value_present=(ccvp == 1),
+                                config_changed=(cc == 1))
+
+    def __index__(self):
+        bits = 0
+        bits |= (int(self.state) & 0x1)
+        bits |= (int(self.config_changed_value_present) & 0x1) << 1
+        bits |= (int(self.config_changed) & 0x1) << 2
+        return bits
+
+
+class InitialDiagnosticsPayload(MqttPayload):
+    FORMAT = '=IBbIB'
+
+    ip: int
+    fw_version: int
+    rssi: int
+    free_heap: int
+    flags: DiagnosticsFlags
+
+
+class DiagnosticsPayload(MqttPayload):
+    FORMAT = '=bIB'
+
+    rssi: int
+    free_heap: int
+    flags: DiagnosticsFlags
+
+
+class MqttDiagnosticsModule(MqttModule):
+    def on_connect(self, mqtt: MqttNode):
+        super().on_connect(mqtt)
+        for topic in ('diag', 'd1ag', 'stat', 'stat1'):
+            mqtt.subscribe_module(topic, self)
+
+    def handle_payload(self, mqtt: MqttNode, topic: str, payload: bytes) -> Optional[MqttPayload]:
+        message = None
+        if topic in ('stat', 'diag'):
+            message = DiagnosticsPayload.unpack(payload)
+        elif topic in ('stat1', 'd1ag'):
+            message = InitialDiagnosticsPayload.unpack(payload)
+        if message:
+            self._logger.debug(message)
+        return message
diff --git a/include/py/homekit/mqtt/module/inverter.py b/include/py/homekit/mqtt/module/inverter.py
new file mode 100644
index 0000000..29bde0a
--- /dev/null
+++ b/include/py/homekit/mqtt/module/inverter.py
@@ -0,0 +1,195 @@
+import time
+import json
+import datetime
+try:
+    import inverterd
+except:
+    pass
+
+from typing import Optional
+from .._module import MqttModule
+from .._node import MqttNode
+from .._payload import MqttPayload, bit_field
+try:
+    from homekit.database import InverterDatabase
+except:
+    pass
+
+_mult_10 = lambda n: int(n*10)
+_div_10 = lambda n: n/10
+
+
+MODULE_NAME = 'MqttInverterModule'
+
+STATUS_TOPIC = 'status'
+GENERATION_TOPIC = 'generation'
+
+
+class MqttInverterStatusPayload(MqttPayload):
+    # 46 bytes
+    FORMAT = 'IHHHHHHBHHHHHBHHHHHHHH'
+
+    PACKER = {
+        'grid_voltage': _mult_10,
+        'grid_freq': _mult_10,
+        'ac_output_voltage': _mult_10,
+        'ac_output_freq': _mult_10,
+        'battery_voltage': _mult_10,
+        'battery_voltage_scc': _mult_10,
+        'battery_voltage_scc2': _mult_10,
+        'pv1_input_voltage': _mult_10,
+        'pv2_input_voltage': _mult_10
+    }
+    UNPACKER = {
+        'grid_voltage': _div_10,
+        'grid_freq': _div_10,
+        'ac_output_voltage': _div_10,
+        'ac_output_freq': _div_10,
+        'battery_voltage': _div_10,
+        'battery_voltage_scc': _div_10,
+        'battery_voltage_scc2': _div_10,
+        'pv1_input_voltage': _div_10,
+        'pv2_input_voltage': _div_10
+    }
+
+    time: int
+    grid_voltage: float
+    grid_freq: float
+    ac_output_voltage: float
+    ac_output_freq: float
+    ac_output_apparent_power: int
+    ac_output_active_power: int
+    output_load_percent: int
+    battery_voltage: float
+    battery_voltage_scc: float
+    battery_voltage_scc2: float
+    battery_discharge_current: int
+    battery_charge_current: int
+    battery_capacity: int
+    inverter_heat_sink_temp: int
+    mppt1_charger_temp: int
+    mppt2_charger_temp: int
+    pv1_input_power: int
+    pv2_input_power: int
+    pv1_input_voltage: float
+    pv2_input_voltage: float
+
+    # H
+    mppt1_charger_status: bit_field(0, 16, 2)
+    mppt2_charger_status: bit_field(0, 16, 2)
+    battery_power_direction: bit_field(0, 16, 2)
+    dc_ac_power_direction: bit_field(0, 16, 2)
+    line_power_direction: bit_field(0, 16, 2)
+    load_connected: bit_field(0, 16, 1)
+
+
+class MqttInverterGenerationPayload(MqttPayload):
+    # 8 bytes
+    FORMAT = 'II'
+
+    time: int
+    wh: int
+
+
+class MqttInverterModule(MqttModule):
+    _status_poll_freq: int
+    _generation_poll_freq: int
+    _inverter: Optional[inverterd.Client]
+    _database: Optional[InverterDatabase]
+    _gen_prev: float
+
+    def __init__(self, status_poll_freq=0, generation_poll_freq=0):
+        super().__init__(tick_interval=status_poll_freq)
+        self._status_poll_freq = status_poll_freq
+        self._generation_poll_freq = generation_poll_freq
+
+        # this defines whether this is a publisher or a subscriber
+        if status_poll_freq > 0:
+            self._inverter = inverterd.Client()
+            self._inverter.connect()
+            self._inverter.format(inverterd.Format.SIMPLE_JSON)
+            self._database = None
+        else:
+            self._inverter = None
+            self._database = InverterDatabase()
+
+        self._gen_prev = 0
+
+    def on_connect(self, mqtt: MqttNode):
+        super().on_connect(mqtt)
+        if not self._inverter:
+            mqtt.subscribe_module(STATUS_TOPIC, self)
+            mqtt.subscribe_module(GENERATION_TOPIC, self)
+
+    def tick(self):
+        if not self._inverter:
+            return
+
+        # read status
+        now = time.time()
+        try:
+            raw = self._inverter.exec('get-status')
+        except inverterd.InverterError as e:
+            self._logger.error(f'inverter error: {str(e)}')
+            # TODO send to server
+            return
+
+        data = json.loads(raw)['data']
+        status = MqttInverterStatusPayload(time=round(now), **data)
+        self._mqtt_node_ref.publish(STATUS_TOPIC, status.pack())
+
+        # read today's generation stat
+        now = time.time()
+        if self._gen_prev == 0 or now - self._gen_prev >= self._generation_poll_freq:
+            self._gen_prev = now
+            today = datetime.date.today()
+            try:
+                raw = self._inverter.exec('get-day-generated', (today.year, today.month, today.day))
+            except inverterd.InverterError as e:
+                self._logger.error(f'inverter error: {str(e)}')
+                # TODO send to server
+                return
+
+            data = json.loads(raw)['data']
+            gen = MqttInverterGenerationPayload(time=round(now), wh=data['wh'])
+            self._mqtt_node_ref.publish(GENERATION_TOPIC, gen.pack())
+
+    def handle_payload(self, mqtt: MqttNode, topic: str, payload: bytes) -> Optional[MqttPayload]:
+        home_id = 1  # legacy compat
+
+        if topic == STATUS_TOPIC:
+            s = MqttInverterStatusPayload.unpack(payload)
+            self._database.add_status(home_id=home_id,
+                                      client_time=s.time,
+                                      grid_voltage=int(s.grid_voltage*10),
+                                      grid_freq=int(s.grid_freq * 10),
+                                      ac_output_voltage=int(s.ac_output_voltage * 10),
+                                      ac_output_freq=int(s.ac_output_freq * 10),
+                                      ac_output_apparent_power=s.ac_output_apparent_power,
+                                      ac_output_active_power=s.ac_output_active_power,
+                                      output_load_percent=s.output_load_percent,
+                                      battery_voltage=int(s.battery_voltage * 10),
+                                      battery_voltage_scc=int(s.battery_voltage_scc * 10),
+                                      battery_voltage_scc2=int(s.battery_voltage_scc2 * 10),
+                                      battery_discharge_current=s.battery_discharge_current,
+                                      battery_charge_current=s.battery_charge_current,
+                                      battery_capacity=s.battery_capacity,
+                                      inverter_heat_sink_temp=s.inverter_heat_sink_temp,
+                                      mppt1_charger_temp=s.mppt1_charger_temp,
+                                      mppt2_charger_temp=s.mppt2_charger_temp,
+                                      pv1_input_power=s.pv1_input_power,
+                                      pv2_input_power=s.pv2_input_power,
+                                      pv1_input_voltage=int(s.pv1_input_voltage * 10),
+                                      pv2_input_voltage=int(s.pv2_input_voltage * 10),
+                                      mppt1_charger_status=s.mppt1_charger_status,
+                                      mppt2_charger_status=s.mppt2_charger_status,
+                                      battery_power_direction=s.battery_power_direction,
+                                      dc_ac_power_direction=s.dc_ac_power_direction,
+                                      line_power_direction=s.line_power_direction,
+                                      load_connected=s.load_connected)
+            return s
+
+        elif topic == GENERATION_TOPIC:
+            gen = MqttInverterGenerationPayload.unpack(payload)
+            self._database.add_generation(home_id, gen.time, gen.wh)
+            return gen
diff --git a/include/py/homekit/mqtt/module/ota.py b/include/py/homekit/mqtt/module/ota.py
new file mode 100644
index 0000000..cd34332
--- /dev/null
+++ b/include/py/homekit/mqtt/module/ota.py
@@ -0,0 +1,77 @@
+import hashlib
+
+from typing import Optional
+from .._payload import MqttPayload
+from .._node import MqttModule, MqttNode
+
+MODULE_NAME = 'MqttOtaModule'
+
+
+class OtaResultPayload(MqttPayload):
+    FORMAT = '=BB'
+    result: int
+    error_code: int
+
+
+class OtaPayload(MqttPayload):
+    secret: str
+    filename: str
+
+    # structure of returned data:
+    #
+    # uint8_t[len(secret)] secret;
+    # uint8_t[16] md5;
+    # *uint8_t data
+
+    def pack(self):
+        buf = bytearray(self.secret.encode())
+        m = hashlib.md5()
+        with open(self.filename, 'rb') as fd:
+            content = fd.read()
+            m.update(content)
+            buf.extend(m.digest())
+            buf.extend(content)
+        return buf
+
+    def unpack(cls, buf: bytes):
+        raise RuntimeError(f'{cls.__class__.__name__}.unpack: not implemented')
+        # secret = buf[:12].decode()
+        # filename = buf[12:].decode()
+        # return OTAPayload(secret=secret, filename=filename)
+
+
+class MqttOtaModule(MqttModule):
+    _ota_request: Optional[tuple[str, int]]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._ota_request = None
+
+    def on_connect(self, mqtt: MqttNode):
+        super().on_connect(mqtt)
+        mqtt.subscribe_module("otares", self)
+
+        if self._ota_request is not None:
+            filename, qos = self._ota_request
+            self._ota_request = None
+            self.do_push_ota(self._mqtt_node_ref.secret, filename, qos)
+
+    def handle_payload(self, mqtt: MqttNode, topic: str, payload: bytes) -> Optional[MqttPayload]:
+        if topic == 'otares':
+            message = OtaResultPayload.unpack(payload)
+            self._logger.debug(message)
+            return message
+
+    def do_push_ota(self, secret: str, filename: str, qos: int):
+        payload = OtaPayload(secret=secret, filename=filename)
+        self._mqtt_node_ref.publish('ota',
+                                    payload=payload.pack(),
+                                    qos=qos)
+
+    def push_ota(self,
+                 filename: str,
+                 qos: int):
+        if not self._initialized:
+            self._ota_request = (filename, qos)
+        else:
+            self.do_push_ota(filename, qos)
diff --git a/include/py/homekit/mqtt/module/relay.py b/include/py/homekit/mqtt/module/relay.py
new file mode 100644
index 0000000..e968031
--- /dev/null
+++ b/include/py/homekit/mqtt/module/relay.py
@@ -0,0 +1,92 @@
+import datetime
+
+from typing import Optional
+from .. import MqttModule, MqttPayload, MqttNode
+
+MODULE_NAME = 'MqttRelayModule'
+
+
+class MqttPowerSwitchPayload(MqttPayload):
+    FORMAT = '=12sB'
+    PACKER = {
+        'state': lambda n: int(n),
+        'secret': lambda s: s.encode('utf-8')
+    }
+    UNPACKER = {
+        'state': lambda n: bool(n),
+        'secret': lambda s: s.decode('utf-8')
+    }
+
+    secret: str
+    state: bool
+
+
+class MqttPowerStatusPayload(MqttPayload):
+    FORMAT = '=B'
+    PACKER = {
+        'opened': lambda n: int(n),
+    }
+    UNPACKER = {
+        'opened': lambda n: bool(n),
+    }
+
+    opened: bool
+
+
+class MqttRelayState:
+    enabled: bool
+    update_time: datetime.datetime
+    rssi: int
+    fw_version: int
+    ever_updated: bool
+
+    def __init__(self):
+        self.ever_updated = False
+        self.enabled = False
+        self.rssi = 0
+
+    def update(self,
+               enabled: bool,
+               rssi: int,
+               fw_version=None):
+        self.ever_updated = True
+        self.enabled = enabled
+        self.rssi = rssi
+        self.update_time = datetime.datetime.now()
+        if fw_version:
+            self.fw_version = fw_version
+
+
+class MqttRelayModule(MqttModule):
+    _legacy_topics: bool
+
+    def __init__(self, legacy_topics=False, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._legacy_topics = legacy_topics
+
+    def on_connect(self, mqtt: MqttNode):
+        super().on_connect(mqtt)
+        mqtt.subscribe_module(self._get_switch_topic(), self)
+        mqtt.subscribe_module('relay/status', self)
+
+    def switchpower(self,
+                    enable: bool):
+        payload = MqttPowerSwitchPayload(secret=self._mqtt_node_ref.secret,
+                                         state=enable)
+        self._mqtt_node_ref.publish(self._get_switch_topic(),
+                                    payload=payload.pack())
+
+    def handle_payload(self, mqtt: MqttNode, topic: str, payload: bytes) -> Optional[MqttPayload]:
+        message = None
+
+        if topic == self._get_switch_topic():
+            message = MqttPowerSwitchPayload.unpack(payload)
+        elif topic == 'relay/status':
+            message = MqttPowerStatusPayload.unpack(payload)
+
+        if message is not None:
+            self._logger.debug(message)
+            return message
+
+    def _get_switch_topic(self) -> str:
+        return 'relay/power' if self._legacy_topics else 'relay/switch'
diff --git a/include/py/homekit/mqtt/module/temphum.py b/include/py/homekit/mqtt/module/temphum.py
new file mode 100644
index 0000000..fd02cca
--- /dev/null
+++ b/include/py/homekit/mqtt/module/temphum.py
@@ -0,0 +1,82 @@
+from .._node import MqttNode
+from .._module import MqttModule
+from .._payload import MqttPayload
+from typing import Optional
+from ...temphum import BaseSensor
+
+two_digits_precision = lambda x: round(x, 2)
+
+MODULE_NAME = 'MqttTempHumModule'
+DATA_TOPIC = 'temphum/data'
+
+
+class MqttTemphumDataPayload(MqttPayload):
+    FORMAT = '=ddb'
+    UNPACKER = {
+        'temp': two_digits_precision,
+        'rh': two_digits_precision
+    }
+
+    temp: float
+    rh: float
+    error: int
+
+
+# class MqttTempHumNodes(HashableEnum):
+#     KBN_SH_HALL = auto()
+#     KBN_SH_BATHROOM = auto()
+#     KBN_SH_LIVINGROOM = auto()
+#     KBN_SH_BEDROOM = auto()
+#
+#     KBN_BH_2FL = auto()
+#     KBN_BH_2FL_STREET = auto()
+#     KBN_BH_1FL_LIVINGROOM = auto()
+#     KBN_BH_1FL_BEDROOM = auto()
+#     KBN_BH_1FL_BATHROOM = auto()
+#
+#     KBN_NH_1FL_INV = auto()
+#     KBN_NH_1FL_CENTER = auto()
+#     KBN_NH_1LF_KT = auto()
+#     KBN_NH_1FL_DS = auto()
+#     KBN_NH_1FS_EZ = auto()
+#
+#     SPB_FLAT120_CABINET = auto()
+
+
+class MqttTempHumModule(MqttModule):
+    def __init__(self,
+                 sensor: Optional[BaseSensor] = None,
+                 write_to_database=False,
+                 *args, **kwargs):
+        if sensor is not None:
+            kwargs['tick_interval'] = 10
+        super().__init__(*args, **kwargs)
+        self._sensor = sensor
+
+    def on_connect(self, mqtt: MqttNode):
+        super().on_connect(mqtt)
+        mqtt.subscribe_module(DATA_TOPIC, self)
+
+    def tick(self):
+        if not self._sensor:
+            return
+
+        error = 0
+        temp = 0
+        rh = 0
+        try:
+            temp = self._sensor.temperature()
+            rh = self._sensor.humidity()
+        except:
+            error = 1
+        pld = MqttTemphumDataPayload(temp=temp, rh=rh, error=error)
+        self._mqtt_node_ref.publish(DATA_TOPIC, pld.pack())
+
+    def handle_payload(self,
+                       mqtt: MqttNode,
+                       topic: str,
+                       payload: bytes) -> Optional[MqttPayload]:
+        if topic == DATA_TOPIC:
+            message = MqttTemphumDataPayload.unpack(payload)
+            self._logger.debug(message)
+            return message
diff --git a/include/py/homekit/pio/__init__.py b/include/py/homekit/pio/__init__.py
new file mode 100644
index 0000000..7216bc4
--- /dev/null
+++ b/include/py/homekit/pio/__init__.py
@@ -0,0 +1 @@
+from .products import get_products, platformio_ini
\ No newline at end of file
diff --git a/include/py/homekit/pio/exceptions.py b/include/py/homekit/pio/exceptions.py
new file mode 100644
index 0000000..a6afd20
--- /dev/null
+++ b/include/py/homekit/pio/exceptions.py
@@ -0,0 +1,2 @@
+class ProductConfigNotFoundError(Exception):
+    pass
diff --git a/include/py/homekit/pio/products.py b/include/py/homekit/pio/products.py
new file mode 100644
index 0000000..388da03
--- /dev/null
+++ b/include/py/homekit/pio/products.py
@@ -0,0 +1,113 @@
+import os
+import logging
+
+from io import StringIO
+from collections import OrderedDict
+
+
+_logger = logging.getLogger(__name__)
+_products_dir = os.path.join(
+    os.path.dirname(__file__),
+    '..', '..', '..',
+    'platformio'
+)
+
+
+def get_products():
+    products = []
+    for f in os.listdir(_products_dir):
+        if f in ('common',):
+            continue
+
+        if os.path.isdir(os.path.join(_products_dir, f)):
+            products.append(f)
+
+    return products
+
+
+def platformio_ini(product_config: dict,
+                   target: str,
+                   # node_id: str,
+                   build_specific_defines: dict,
+                   build_specific_defines_enums: list[str],
+                   platform: str,
+                   framework: str = 'arduino',
+                   upload_port: str = '/dev/ttyUSB0',
+                   monitor_speed: int = 115200,
+                   debug=False,
+                   debug_network=False) -> str:
+    node_id = build_specific_defines['CONFIG_NODE_ID']
+
+    # defines
+    defines = {
+        **product_config['common_defines'],
+        'CONFIG_NODE_ID': node_id,
+        'CONFIG_WIFI_AP_SSID': ('HK_'+node_id)[:31]
+    }
+    try:
+        defines.update(product_config['target_defines'][target])
+    except KeyError:
+        pass
+    defines['CONFIG_NODE_SECRET_SIZE'] = len(defines['CONFIG_NODE_SECRET'])
+    defines['CONFIG_MQTT_CLIENT_ID'] = node_id
+
+    build_type = 'release'
+    if debug:
+        defines['DEBUG'] = True
+        build_type = 'debug'
+    if debug_network:
+        defines['DEBUG'] = True
+        defines['DEBUG_ESP_SSL'] = True
+        defines['DEBUG_ESP_PORT'] = 'Serial'
+        build_type = 'debug'
+    if build_specific_defines:
+        for k, v in build_specific_defines.items():
+            defines[k] = v
+    defines = OrderedDict(sorted(defines.items(), key=lambda t: t[0]))
+
+    # libs
+    libs = []
+    if 'common_libs' in product_config:
+        libs.extend(product_config['common_libs'])
+    if 'target_libs' in product_config and target in product_config['target_libs']:
+        libs.extend(product_config['target_libs'][target])
+    libs = list(set(libs))
+    libs.sort()
+
+    try:
+        target_real_name = product_config['target_board_names'][target]
+    except KeyError:
+        target_real_name = target
+
+    buf = StringIO()
+
+    buf.write('; Generated by pio_ini.py\n\n')
+    buf.write(f'[env:{target_real_name}]\n')
+    buf.write(f'platform = {platform}\n')
+    buf.write(f'board = {target_real_name}\n')
+    buf.write(f'framework = {framework}\n')
+    buf.write(f'upload_port = {upload_port}\n')
+    buf.write(f'monitor_speed = {monitor_speed}\n')
+    if libs:
+        buf.write(f'lib_deps =')
+        for lib in libs:
+            buf.write(f'    {lib}\n')
+    buf.write(f'build_flags =\n')
+    if defines:
+        for name, value in defines.items():
+            buf.write(f'    -D{name}')
+            is_enum = name in build_specific_defines_enums
+            if type(value) is not bool:
+                buf.write('=')
+                if type(value) is str:
+                    if not is_enum:
+                        buf.write('"\\"')
+                    value = value.replace('"', '\\"')
+                buf.write(f'{value}')
+                if type(value) is str and not is_enum:
+                    buf.write('"\\"')
+            buf.write('\n')
+        buf.write(f'    -I../common/include')
+    buf.write(f'\nbuild_type = {build_type}')
+
+    return buf.getvalue()
diff --git a/include/py/homekit/relay/__init__.py b/include/py/homekit/relay/__init__.py
new file mode 100644
index 0000000..406403d
--- /dev/null
+++ b/include/py/homekit/relay/__init__.py
@@ -0,0 +1,16 @@
+import importlib
+
+__all__ = ['RelayClient', 'RelayServer']
+
+
+def __getattr__(name):
+    _map = {
+        'RelayClient': '.sunxi_h3_client',
+        'RelayServer': '.sunxi_h3_server'
+    }
+
+    if name in __all__:
+        module = importlib.import_module(_map[name], __name__)
+        return getattr(module, name)
+
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
diff --git a/include/py/homekit/relay/__init__.pyi b/include/py/homekit/relay/__init__.pyi
new file mode 100644
index 0000000..7a4a2f4
--- /dev/null
+++ b/include/py/homekit/relay/__init__.pyi
@@ -0,0 +1,2 @@
+from .sunxi_h3_client import RelayClient as RelayClient
+from .sunxi_h3_server import RelayServer as RelayServer
diff --git a/include/py/homekit/relay/sunxi_h3_client.py b/include/py/homekit/relay/sunxi_h3_client.py
new file mode 100644
index 0000000..8c8d6c4
--- /dev/null
+++ b/include/py/homekit/relay/sunxi_h3_client.py
@@ -0,0 +1,39 @@
+import socket
+
+
+class RelayClient:
+    def __init__(self, port=8307, host='127.0.0.1'):
+        self._host = host
+        self._port = port
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+
+    def __del__(self):
+        self.sock.close()
+
+    def connect(self):
+        self.sock.connect((self._host, self._port))
+
+    def _write(self, line):
+        self.sock.sendall((line+'\r\n').encode())
+
+    def _read(self):
+        buf = bytearray()
+        while True:
+            buf.extend(self.sock.recv(256))
+            if b'\r\n' in buf:
+                break
+
+        response = buf.decode().strip()
+        return response
+
+    def on(self):
+        self._write('on')
+        return self._read()
+
+    def off(self):
+        self._write('off')
+        return self._read()
+
+    def status(self):
+        self._write('get')
+        return self._read()
diff --git a/include/py/homekit/relay/sunxi_h3_server.py b/include/py/homekit/relay/sunxi_h3_server.py
new file mode 100644
index 0000000..1f33969
--- /dev/null
+++ b/include/py/homekit/relay/sunxi_h3_server.py
@@ -0,0 +1,82 @@
+import asyncio
+import logging
+
+from pyA20.gpio import gpio
+from pyA20.gpio import port as gpioport
+from ..util import Addr
+
+logger = logging.getLogger(__name__)
+
+
+class RelayServer:
+    OFF = 1
+    ON = 0
+
+    def __init__(self,
+                 pinname: str,
+                 addr: Addr):
+        if not hasattr(gpioport, pinname):
+            raise ValueError(f'invalid pin {pinname}')
+
+        self.pin = getattr(gpioport, pinname)
+        self.addr = addr
+
+        gpio.init()
+        gpio.setcfg(self.pin, gpio.OUTPUT)
+
+        self.lock = asyncio.Lock()
+
+    def run(self):
+        asyncio.run(self.run_server())
+
+    async def relay_set(self, value):
+        async with self.lock:
+            gpio.output(self.pin, value)
+
+    async def relay_get(self):
+        async with self.lock:
+            return int(gpio.input(self.pin)) == RelayServer.ON
+
+    async def handle_client(self, reader, writer):
+        request = None
+        while request != 'quit':
+            try:
+                request = await reader.read(255)
+                if request == b'\x04':
+                    break
+                request = request.decode('utf-8').strip()
+            except Exception:
+                break
+
+            data = 'unknown'
+            if request == 'on':
+                await self.relay_set(RelayServer.ON)
+                logger.debug('set on')
+                data = 'ok'
+
+            elif request == 'off':
+                await self.relay_set(RelayServer.OFF)
+                logger.debug('set off')
+                data = 'ok'
+
+            elif request == 'get':
+                status = await self.relay_get()
+                data = 'on' if status is True else 'off'
+
+            writer.write((data + '\r\n').encode('utf-8'))
+            try:
+                await writer.drain()
+            except ConnectionError:
+                break
+
+        try:
+            writer.close()
+        except ConnectionError:
+            pass
+
+    async def run_server(self):
+        host, port = self.addr
+        server = await asyncio.start_server(self.handle_client, host, port)
+        async with server:
+            logger.info('Server started.')
+            await server.serve_forever()
diff --git a/include/py/homekit/soundsensor/__init__.py b/include/py/homekit/soundsensor/__init__.py
new file mode 100644
index 0000000..30052f8
--- /dev/null
+++ b/include/py/homekit/soundsensor/__init__.py
@@ -0,0 +1,22 @@
+import importlib
+
+__all__ = [
+    'SoundSensorNode',
+    'SoundSensorHitHandler',
+    'SoundSensorServer',
+    'SoundSensorServerGuardClient'
+]
+
+
+def __getattr__(name):
+    if name in __all__:
+        if name == 'SoundSensorNode':
+            file = 'node'
+        elif name == 'SoundSensorServerGuardClient':
+            file = 'server_client'
+        else:
+            file = 'server'
+        module = importlib.import_module(f'.{file}', __name__)
+        return getattr(module, name)
+
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
diff --git a/include/py/homekit/soundsensor/__init__.pyi b/include/py/homekit/soundsensor/__init__.pyi
new file mode 100644
index 0000000..cb34972
--- /dev/null
+++ b/include/py/homekit/soundsensor/__init__.pyi
@@ -0,0 +1,8 @@
+from .server import (
+    SoundSensorHitHandler as SoundSensorHitHandler,
+    SoundSensorServer as SoundSensorServer,
+)
+from .server_client import (
+    SoundSensorServerGuardClient as SoundSensorServerGuardClient
+)
+from .node import SoundSensorNode as SoundSensorNode
diff --git a/include/py/homekit/soundsensor/node.py b/include/py/homekit/soundsensor/node.py
new file mode 100644
index 0000000..292452f
--- /dev/null
+++ b/include/py/homekit/soundsensor/node.py
@@ -0,0 +1,75 @@
+import logging
+import threading
+
+from typing import Optional
+from time import sleep
+from ..util import stringify, send_datagram, Addr
+
+from pyA20.gpio import gpio
+from pyA20.gpio import port as gpioport
+
+logger = logging.getLogger(__name__)
+
+
+class SoundSensorNode:
+    def __init__(self,
+                 name: str,
+                 pinname: str,
+                 server_addr: Optional[Addr],
+                 threshold: int = 1,
+                 delay=0.005):
+
+        if not hasattr(gpioport, pinname):
+            raise ValueError(f'invalid pin {pinname}')
+
+        self.pin = getattr(gpioport, pinname)
+        self.name = name
+        self.delay = delay
+        self.threshold = threshold
+
+        self.server_addr = server_addr
+
+        self.hits = 0
+        self.hitlock = threading.Lock()
+
+        self.interrupted = False
+
+    def run(self):
+        try:
+            t = threading.Thread(target=self.sensor_reader)
+            t.daemon = True
+            t.start()
+
+            while True:
+                with self.hitlock:
+                    hits = self.hits
+                    self.hits = 0
+
+                if hits >= self.threshold:
+                    try:
+                        if self.server_addr is not None:
+                            send_datagram(stringify([self.name, hits]), self.server_addr)
+                        else:
+                            logger.debug(f'server reporting disabled, skipping reporting {hits} hits')
+                    except OSError as exc:
+                        logger.exception(exc)
+
+                sleep(1)
+
+        except (KeyboardInterrupt, SystemExit) as e:
+            self.interrupted = True
+            logger.info(str(e))
+
+    def sensor_reader(self):
+        gpio.init()
+        gpio.setcfg(self.pin, gpio.INPUT)
+        gpio.pullup(self.pin, gpio.PULLUP)
+
+        while not self.interrupted:
+            state = gpio.input(self.pin)
+            sleep(self.delay)
+
+            if not state:
+                with self.hitlock:
+                    logger.debug('got a hit')
+                    self.hits += 1
diff --git a/include/py/homekit/soundsensor/server.py b/include/py/homekit/soundsensor/server.py
new file mode 100644
index 0000000..a627390
--- /dev/null
+++ b/include/py/homekit/soundsensor/server.py
@@ -0,0 +1,128 @@
+import asyncio
+import json
+import logging
+import threading
+
+from ..database.sqlite import SQLiteBase
+from ..config import config
+from .. import http
+
+from typing import Type
+from ..util import Addr
+
+logger = logging.getLogger(__name__)
+
+
+class SoundSensorHitHandler(asyncio.DatagramProtocol):
+    def datagram_received(self, data, addr):
+        try:
+            data = json.loads(data)
+        except json.JSONDecodeError as e:
+            logger.error('failed to parse json datagram')
+            logger.exception(e)
+            return
+
+        try:
+            name, hits = data
+        except (ValueError, IndexError) as e:
+            logger.error('failed to unpack data')
+            logger.exception(e)
+            return
+
+        self.handler(name, hits)
+
+    def handler(self, name: str, hits: int):
+        pass
+
+
+class Database(SQLiteBase):
+    SCHEMA = 1
+
+    def __init__(self):
+        super().__init__(dbname='sound_sensor_server')
+
+    def schema_init(self, version: int) -> None:
+        cursor = self.cursor()
+
+        if version < 1:
+            cursor.execute("CREATE TABLE IF NOT EXISTS status (guard_enabled INTEGER NOT NULL)")
+            cursor.execute("INSERT INTO status (guard_enabled) VALUES (-1)")
+
+        self.commit()
+
+    def get_guard_enabled(self) -> int:
+        cur = self.cursor()
+        cur.execute("SELECT guard_enabled FROM status LIMIT 1")
+        return int(cur.fetchone()[0])
+
+    def set_guard_enabled(self, enabled: bool) -> None:
+        cur = self.cursor()
+        cur.execute("UPDATE status SET guard_enabled=?", (int(enabled),))
+        self.commit()
+
+
+class SoundSensorServer:
+    def __init__(self,
+                 addr: Addr,
+                 handler_impl: Type[SoundSensorHitHandler]):
+        self.addr = addr
+        self.impl = handler_impl
+        self.db = Database()
+
+        self._recording_lock = threading.Lock()
+        self._recording_enabled = True
+
+        if self.guard_control_enabled():
+            current_status = self.db.get_guard_enabled()
+            if current_status == -1:
+                self.set_recording(config['server']['guard_recording_default']
+                                   if 'guard_recording_default' in config['server']
+                                   else False,
+                                   update=False)
+            else:
+                self.set_recording(bool(current_status), update=False)
+
+    @staticmethod
+    def guard_control_enabled() -> bool:
+        return 'guard_control' in config['server'] and config['server']['guard_control'] is True
+
+    def set_recording(self, enabled: bool, update=True):
+        with self._recording_lock:
+            self._recording_enabled = enabled
+        if update:
+            self.db.set_guard_enabled(enabled)
+
+    def is_recording_enabled(self) -> bool:
+        with self._recording_lock:
+            return self._recording_enabled
+
+    def run(self):
+        if self.guard_control_enabled():
+            t = threading.Thread(target=self.run_guard_server)
+            t.daemon = True
+            t.start()
+
+        loop = asyncio.get_event_loop()
+        t = loop.create_datagram_endpoint(self.impl, local_addr=self.addr)
+        loop.run_until_complete(t)
+        loop.run_forever()
+
+    def run_guard_server(self):
+        routes = http.routes()
+
+        @routes.post('/guard/enable')
+        async def guard_enable(request):
+            self.set_recording(True)
+            return http.ok()
+
+        @routes.post('/guard/disable')
+        async def guard_disable(request):
+            self.set_recording(False)
+            return http.ok()
+
+        @routes.get('/guard/status')
+        async def guard_status(request):
+            return http.ok({'enabled': self.is_recording_enabled()})
+
+        asyncio.set_event_loop(asyncio.new_event_loop())  # need to create new event loop in new thread
+        http.serve(self.addr, routes, handle_signals=False)  # handle_signals=True doesn't work in separate thread
diff --git a/include/py/homekit/soundsensor/server_client.py b/include/py/homekit/soundsensor/server_client.py
new file mode 100644
index 0000000..7eef996
--- /dev/null
+++ b/include/py/homekit/soundsensor/server_client.py
@@ -0,0 +1,38 @@
+import requests
+import logging
+
+from ..util import Addr
+from ..api.errors import ApiResponseError
+
+
+class SoundSensorServerGuardClient:
+    def __init__(self, addr: Addr):
+        self.endpoint = f'http://{addr[0]}:{addr[1]}'
+        self.logger = logging.getLogger(self.__class__.__name__)
+
+    def guard_enable(self):
+        return self._call('guard/enable', is_post=True)
+
+    def guard_disable(self):
+        return self._call('guard/disable', is_post=True)
+
+    def guard_status(self):
+        return self._call('guard/status')
+
+    def _call(self,
+              method: str,
+              is_post=False):
+
+        url = f'{self.endpoint}/{method}'
+        self.logger.debug(f'calling {url}')
+
+        r = requests.get(url) if not is_post else requests.post(url)
+
+        if r.status_code != 200:
+            response = r.json()
+            raise ApiResponseError(status_code=r.status_code,
+                                   error_type=response['error'],
+                                   error_message=response['message'] or None,
+                                   error_stacktrace=response['stacktrace'] if 'stacktrace' in response else None)
+
+        return r.json()['response']
diff --git a/include/py/homekit/telegram/__init__.py b/include/py/homekit/telegram/__init__.py
new file mode 100644
index 0000000..a68dae1
--- /dev/null
+++ b/include/py/homekit/telegram/__init__.py
@@ -0,0 +1 @@
+from .telegram import send_message, send_photo
diff --git a/include/py/homekit/telegram/_botcontext.py b/include/py/homekit/telegram/_botcontext.py
new file mode 100644
index 0000000..a143bfe
--- /dev/null
+++ b/include/py/homekit/telegram/_botcontext.py
@@ -0,0 +1,86 @@
+from typing import Optional, List
+
+from telegram import Update, User, CallbackQuery
+from telegram.constants import ParseMode
+from telegram.ext import CallbackContext
+
+from ._botdb import BotDatabase
+from ._botlang import lang
+from ._botutil import IgnoreMarkup, exc2text
+
+
+class Context:
+    _update: Optional[Update]
+    _callback_context: Optional[CallbackContext]
+    _markup_getter: callable
+    db: Optional[BotDatabase]
+    _user_lang: Optional[str]
+
+    def __init__(self,
+                 update: Optional[Update],
+                 callback_context: Optional[CallbackContext],
+                 markup_getter: callable,
+                 store: Optional[BotDatabase]):
+        self._update = update
+        self._callback_context = callback_context
+        self._markup_getter = markup_getter
+        self._store = store
+        self._user_lang = None
+
+    async def reply(self, text, markup=None):
+        if markup is None:
+            markup = self._markup_getter(self)
+        kwargs = dict(parse_mode=ParseMode.HTML)
+        if not isinstance(markup, IgnoreMarkup):
+            kwargs['reply_markup'] = markup
+        return await self._update.message.reply_text(text, **kwargs)
+
+    async def reply_exc(self, e: Exception) -> None:
+        await self.reply(exc2text(e), markup=IgnoreMarkup())
+
+    async def answer(self, text: str = None):
+        await self.callback_query.answer(text)
+
+    async def edit(self, text, markup=None):
+        kwargs = dict(parse_mode=ParseMode.HTML)
+        if not isinstance(markup, IgnoreMarkup):
+            kwargs['reply_markup'] = markup
+        await self.callback_query.edit_message_text(text, **kwargs)
+
+    @property
+    def text(self) -> str:
+        return self._update.message.text
+
+    @property
+    def callback_query(self) -> CallbackQuery:
+        return self._update.callback_query
+
+    @property
+    def args(self) -> Optional[List[str]]:
+        return self._callback_context.args
+
+    @property
+    def user_id(self) -> int:
+        return self.user.id
+
+    @property
+    def user_data(self):
+        return self._callback_context.user_data
+
+    @property
+    def user(self) -> User:
+        return self._update.effective_user
+
+    @property
+    def user_lang(self) -> str:
+        if self._user_lang is None:
+            self._user_lang = self._store.get_user_lang(self.user_id)
+        return self._user_lang
+
+    def lang(self, key: str, *args) -> str:
+        return lang.get(key, self.user_lang, *args)
+
+    def is_callback_context(self) -> bool:
+        return self._update.callback_query \
+               and self._update.callback_query.data \
+               and self._update.callback_query.data != ''
diff --git a/include/py/homekit/telegram/_botdb.py b/include/py/homekit/telegram/_botdb.py
new file mode 100644
index 0000000..4e1aec0
--- /dev/null
+++ b/include/py/homekit/telegram/_botdb.py
@@ -0,0 +1,32 @@
+from homekit.database.sqlite import SQLiteBase
+
+
+class BotDatabase(SQLiteBase):
+    def __init__(self):
+        super().__init__()
+
+    def schema_init(self, version: int) -> None:
+        if version < 1:
+            cursor = self.cursor()
+            cursor.execute("""CREATE TABLE IF NOT EXISTS users (
+                id INTEGER PRIMARY KEY,
+                lang TEXT NOT NULL
+            )""")
+            self.commit()
+
+    def get_user_lang(self, user_id: int, default: str = 'en') -> str:
+        cursor = self.cursor()
+        cursor.execute('SELECT lang FROM users WHERE id=?', (user_id,))
+        row = cursor.fetchone()
+
+        if row is None:
+            cursor.execute('INSERT INTO users (id, lang) VALUES (?, ?)', (user_id, default))
+            self.commit()
+            return default
+        else:
+            return row[0]
+
+    def set_user_lang(self, user_id: int, lang: str) -> None:
+        cursor = self.cursor()
+        cursor.execute('UPDATE users SET lang=? WHERE id=?', (lang, user_id))
+        self.commit()
diff --git a/include/py/homekit/telegram/_botlang.py b/include/py/homekit/telegram/_botlang.py
new file mode 100644
index 0000000..f5f85bb
--- /dev/null
+++ b/include/py/homekit/telegram/_botlang.py
@@ -0,0 +1,120 @@
+import logging
+
+from typing import Optional, Dict, List, Union
+
+_logger = logging.getLogger(__name__)
+
+
+class LangStrings(dict):
+    _lang: Optional[str]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._lang = None
+
+    def setlang(self, lang: str):
+        self._lang = lang
+
+    def __missing__(self, key):
+        _logger.warning(f'key {key} is missing in language {self._lang}')
+        return '{%s}' % key
+
+    def __setitem__(self, key, value):
+        raise NotImplementedError(f'setting translation strings this way is prohibited (was trying to set {key}={value})')
+
+
+class LangPack:
+    strings: Dict[str, LangStrings[str, str]]
+    default_lang: str
+
+    def __init__(self):
+        self.strings = {}
+        self.default_lang = 'en'
+
+    def ru(self, **kwargs) -> None:
+        self.set(kwargs, 'ru')
+
+    def en(self, **kwargs) -> None:
+        self.set(kwargs, 'en')
+
+    def set(self,
+            strings: Union[LangStrings, dict],
+            lang: str) -> None:
+
+        if isinstance(strings, dict) and not isinstance(strings, LangStrings):
+            strings = LangStrings(**strings)
+            strings.setlang(lang)
+
+        if lang not in self.strings:
+            self.strings[lang] = strings
+        else:
+            self.strings[lang].update(strings)
+
+    def all(self, key):
+        result = []
+        for strings in self.strings.values():
+            result.append(strings[key])
+        return result
+
+    @property
+    def languages(self) -> List[str]:
+        return list(self.strings.keys())
+
+    def get(self, key: str, lang: str, *args) -> str:
+        if args:
+            return self.strings[lang][key] % args
+        else:
+            return self.strings[lang][key]
+
+    def get_langpack(self, _lang: str) -> dict:
+        return self.strings[_lang]
+
+    def __call__(self, *args, **kwargs):
+        return self.strings[self.default_lang][args[0]]
+
+    def __getitem__(self, key):
+        return self.strings[self.default_lang][key]
+
+    def __setitem__(self, key, value):
+        raise NotImplementedError('setting translation strings this way is prohibited')
+
+    def __contains__(self, key):
+        return key in self.strings[self.default_lang]
+
+    @staticmethod
+    def pfx(prefix: str, l: list) -> list:
+        return list(map(lambda s: f'{prefix}{s}', l))
+
+
+
+languages = {
+    'en': 'English',
+    'ru': 'Русский'
+}
+
+
+lang = LangPack()
+lang.en(
+    en='English',
+    ru='Russian',
+    start_message="Select command on the keyboard.",
+    unknown_message="Unknown message",
+    cancel="🚫 Cancel",
+    back='🔙 Back',
+    select_language="Select language on the keyboard.",
+    invalid_language="Invalid language. Please try again.",
+    saved='Saved.',
+    please_wait="⏳ Please wait..."
+)
+lang.ru(
+    en='Английский',
+    ru='Русский',
+    start_message="Выберите команду на клавиатуре.",
+    unknown_message="Неизвестная команда",
+    cancel="🚫 Отмена",
+    back='🔙 Назад',
+    select_language="Выберите язык на клавиатуре.",
+    invalid_language="Неверный язык. Пожалуйста, попробуйте снова",
+    saved="Настройки сохранены.",
+    please_wait="⏳ Ожидайте..."
+)
\ No newline at end of file
diff --git a/include/py/homekit/telegram/_botutil.py b/include/py/homekit/telegram/_botutil.py
new file mode 100644
index 0000000..111a704
--- /dev/null
+++ b/include/py/homekit/telegram/_botutil.py
@@ -0,0 +1,47 @@
+import logging
+import traceback
+
+from html import escape
+from telegram import User
+from homekit.api import WebApiClient as APIClient
+from homekit.api.types import BotType
+from homekit.api.errors import ApiResponseError
+
+_logger = logging.getLogger(__name__)
+
+
+def user_any_name(user: User) -> str:
+    name = [user.first_name, user.last_name]
+    name = list(filter(lambda s: s is not None, name))
+    name = ' '.join(name).strip()
+
+    if not name:
+        name = user.username
+
+    if not name:
+        name = str(user.id)
+
+    return name
+
+
+class ReportingHelper:
+    def __init__(self, client: APIClient, bot_type: BotType):
+        self.client = client
+        self.bot_type = bot_type
+
+    def report(self, message, text: str = None) -> None:
+        if text is None:
+            text = message.text
+        try:
+            self.client.log_bot_request(self.bot_type, message.chat_id, text)
+        except ApiResponseError as error:
+            _logger.exception(error)
+
+
+def exc2text(e: Exception) -> str:
+    tb = ''.join(traceback.format_tb(e.__traceback__))
+    return f'{e.__class__.__name__}: ' + escape(str(e)) + "\n\n" + escape(tb)
+
+
+class IgnoreMarkup:
+    pass
diff --git a/include/py/homekit/telegram/aio.py b/include/py/homekit/telegram/aio.py
new file mode 100644
index 0000000..fc87c1c
--- /dev/null
+++ b/include/py/homekit/telegram/aio.py
@@ -0,0 +1,18 @@
+import functools
+import asyncio
+
+from .telegram import (
+    send_message as _send_message_sync,
+    send_photo as _send_photo_sync
+)
+
+
+async def send_message(*args, **kwargs):
+    loop = asyncio.get_event_loop()
+    return await loop.run_in_executor(None, functools.partial(_send_message_sync, *args, **kwargs))
+
+
+async def send_photo(*args, **kwargs):
+    loop = asyncio.get_event_loop()
+    return await loop.run_in_executor(None, functools.partial(_send_photo_sync, *args, **kwargs))
+
diff --git a/include/py/homekit/telegram/bot.py b/include/py/homekit/telegram/bot.py
new file mode 100644
index 0000000..2e33bea
--- /dev/null
+++ b/include/py/homekit/telegram/bot.py
@@ -0,0 +1,583 @@
+from __future__ import annotations
+
+import logging
+import itertools
+
+from enum import Enum, auto
+from functools import wraps
+from typing import Optional, Union, Tuple, Coroutine
+
+from telegram import Update, ReplyKeyboardMarkup
+from telegram.ext import (
+    Application,
+    filters,
+    CommandHandler,
+    MessageHandler,
+    CallbackQueryHandler,
+    CallbackContext,
+    ConversationHandler
+)
+from telegram.ext.filters import BaseFilter
+from telegram.error import TimedOut
+
+from homekit.config import config
+from homekit.api import WebApiClient
+from homekit.api.types import BotType
+
+from ._botlang import lang, languages
+from ._botdb import BotDatabase
+from ._botutil import ReportingHelper, exc2text, IgnoreMarkup, user_any_name
+from ._botcontext import Context
+
+
+db: Optional[BotDatabase] = None
+
+_user_filter: Optional[BaseFilter] = None
+_cancel_filter = filters.Text(lang.all('cancel'))
+_back_filter = filters.Text(lang.all('back'))
+_cancel_and_back_filter = filters.Text(lang.all('back') + lang.all('cancel'))
+
+_logger = logging.getLogger(__name__)
+_application: Optional[Application] = None
+_reporting: Optional[ReportingHelper] = None
+_exception_handler: Optional[Coroutine] = None
+_dispatcher = None
+_markup_getter: Optional[callable] = None
+_start_handler_ref: Optional[Coroutine] = None
+
+
+def text_filter(*args):
+    if not _user_filter:
+        raise RuntimeError('user_filter is not initialized')
+    return filters.Text(args[0] if isinstance(args[0], list) else [*args]) & _user_filter
+
+
+async def _handler_of_handler(*args, **kwargs):
+    self = None
+    context = None
+    update = None
+
+    _args = list(args)
+    while len(_args):
+        v = _args[0]
+        if isinstance(v, conversation):
+            self = v
+            _args.pop(0)
+        elif isinstance(v, Update):
+            update = v
+            _args.pop(0)
+        elif isinstance(v, CallbackContext):
+            context = v
+            _args.pop(0)
+            break
+
+    ctx = Context(update,
+                  callback_context=context,
+                  markup_getter=lambda _ctx: None if not _markup_getter else _markup_getter(_ctx),
+                  store=db)
+    try:
+        _args.insert(0, ctx)
+
+        f = kwargs['f']
+        del kwargs['f']
+
+        if 'return_with_context' in kwargs:
+            return_with_context = True
+            del kwargs['return_with_context']
+        else:
+            return_with_context = False
+
+        if 'argument' in kwargs and kwargs['argument'] == 'message_key':
+            del kwargs['argument']
+            mkey = None
+            for k, v in lang.get_langpack(ctx.user_lang).items():
+                if ctx.text == v:
+                    mkey = k
+                    break
+            _args.insert(0, mkey)
+
+        if self:
+            _args.insert(0, self)
+
+        result = await f(*_args, **kwargs)
+        return result if not return_with_context else (result, ctx)
+
+    except Exception as e:
+        if _exception_handler:
+            if not _exception_handler(e, ctx) and not isinstance(e, TimedOut):
+                _logger.exception(e)
+                if not ctx.is_callback_context():
+                    await ctx.reply_exc(e)
+                else:
+                    notify_user(ctx.user_id, exc2text(e))
+        else:
+            _logger.exception(e)
+
+
+def handler(**kwargs):
+    def inner(f):
+        @wraps(f)
+        async def _handler(*args, **inner_kwargs):
+            if 'argument' in kwargs and kwargs['argument'] == 'message_key':
+                inner_kwargs['argument'] = 'message_key'
+            return await _handler_of_handler(f=f, *args, **inner_kwargs)
+
+        messages = []
+        texts = []
+
+        if 'messages' in kwargs:
+            messages += kwargs['messages']
+        if 'message' in kwargs:
+            messages.append(kwargs['message'])
+
+        if 'text' in kwargs:
+            texts.append(kwargs['text'])
+        if 'texts' in kwargs:
+            texts += kwargs['texts']
+
+        if messages or texts:
+            new_messages = list(itertools.chain.from_iterable([lang.all(m) for m in messages]))
+            texts += new_messages
+            texts = list(set(texts))
+            _application.add_handler(
+                MessageHandler(text_filter(*texts), _handler),
+                group=0
+            )
+
+        if 'command' in kwargs:
+            _application.add_handler(CommandHandler(kwargs['command'], _handler), group=0)
+
+        if 'callback' in kwargs:
+            _application.add_handler(CallbackQueryHandler(_handler, pattern=kwargs['callback']), group=0)
+
+        return _handler
+
+    return inner
+
+
+def simplehandler(f: Coroutine):
+    @wraps(f)
+    async def _handler(*args, **kwargs):
+        return await _handler_of_handler(f=f, *args, **kwargs)
+    return _handler
+
+
+def callbackhandler(*args, **kwargs):
+    def inner(f):
+        @wraps(f)
+        async def _handler(*args, **kwargs):
+            return await _handler_of_handler(f=f, *args, **kwargs)
+        pattern_kwargs = {}
+        if kwargs['callback'] != '*':
+            pattern_kwargs['pattern'] = kwargs['callback']
+        _application.add_handler(CallbackQueryHandler(_handler, **pattern_kwargs), group=0)
+        return _handler
+    return inner
+
+
+async def exceptionhandler(f: callable):
+    global _exception_handler
+    if _exception_handler:
+        _logger.warning('exception handler already set, we will overwrite it')
+    _exception_handler = f
+
+
+def defaultreplymarkup(f: callable):
+    global _markup_getter
+    _markup_getter = f
+
+
+def convinput(state, is_enter=False, **kwargs):
+    def inner(f):
+        f.__dict__['_conv_data'] = dict(
+            orig_f=f,
+            enter=is_enter,
+            type=ConversationMethodType.ENTRY if is_enter and state == 0 else ConversationMethodType.STATE_HANDLER,
+            state=state,
+            **kwargs
+        )
+
+        @wraps(f)
+        async def _impl(*args, **kwargs):
+            result, ctx = await _handler_of_handler(f=f, *args, **kwargs, return_with_context=True)
+            if result == conversation.END:
+                await start(ctx)
+            return result
+
+        return _impl
+
+    return inner
+
+
+def conventer(state, **kwargs):
+    return convinput(state, is_enter=True, **kwargs)
+
+
+class ConversationMethodType(Enum):
+    ENTRY = auto()
+    STATE_HANDLER = auto()
+
+
+class conversation:
+    END = ConversationHandler.END
+    STATE_SEQS = []
+
+    def __init__(self, enable_back=False):
+        self._logger = logging.getLogger(self.__class__.__name__)
+        self._user_state_cache = {}
+        self._back_enabled = enable_back
+
+    def make_handlers(self, f: callable, **kwargs) -> list:
+        messages = {}
+        handlers = []
+
+        if 'messages' in kwargs:
+            if isinstance(kwargs['messages'], dict):
+                messages = kwargs['messages']
+            else:
+                for m in kwargs['messages']:
+                    messages[m] = None
+
+        if 'message' in kwargs:
+            if isinstance(kwargs['message'], str):
+                messages[kwargs['message']] = None
+            else:
+                AttributeError('invalid message type: ' + type(kwargs['message']))
+
+        if messages:
+            for message, target_state in messages.items():
+                if not target_state:
+                    handlers.append(MessageHandler(text_filter(lang.all(message) if 'messages_lang_completed' not in kwargs else message), f))
+                else:
+                    handlers.append(MessageHandler(text_filter(lang.all(message) if 'messages_lang_completed' not in kwargs else message), self.make_invoker(target_state)))
+
+        if 'regex' in kwargs:
+            handlers.append(MessageHandler(filters.Regex(kwargs['regex']) & _user_filter, f))
+
+        if 'command' in kwargs:
+            handlers.append(CommandHandler(kwargs['command'], f, _user_filter))
+
+        return handlers
+
+    def make_invoker(self, state):
+        def _invoke(update: Update, context: CallbackContext):
+            ctx = Context(update,
+                          callback_context=context,
+                          markup_getter=lambda _ctx: None if not _markup_getter else _markup_getter(_ctx),
+                          store=db)
+            return self.invoke(state, ctx)
+        return _invoke
+
+    def invoke(self, state, ctx: Context):
+        self._logger.debug(f'invoke, state={state}')
+        for item in dir(self):
+            f = getattr(self, item)
+            if not callable(f) or item.startswith('_') or '_conv_data' not in f.__dict__:
+                continue
+            cd = f.__dict__['_conv_data']
+            if cd['enter'] and cd['state'] == state:
+                return cd['orig_f'](self, ctx)
+
+        raise RuntimeError(f'invoke: failed to find method for state {state}')
+
+    def get_handler(self) -> ConversationHandler:
+        entry_points = []
+        states = {}
+
+        l_cancel_filter = _cancel_filter if not self._back_enabled else _cancel_and_back_filter
+
+        for item in dir(self):
+            f = getattr(self, item)
+            if not callable(f) or item.startswith('_') or '_conv_data' not in f.__dict__:
+                continue
+
+            cd = f.__dict__['_conv_data']
+
+            if cd['type'] == ConversationMethodType.ENTRY:
+                entry_points = self.make_handlers(f, **cd)
+            elif cd['type'] == ConversationMethodType.STATE_HANDLER:
+                states[cd['state']] = self.make_handlers(f, **cd)
+                states[cd['state']].append(
+                    MessageHandler(_user_filter & ~l_cancel_filter, conversation.invalid)
+                )
+
+        fallbacks = [MessageHandler(_user_filter & _cancel_filter, self.cancel)]
+        if self._back_enabled:
+            fallbacks.append(MessageHandler(_user_filter & _back_filter, self.back))
+
+        return ConversationHandler(
+            entry_points=entry_points,
+            states=states,
+            fallbacks=fallbacks
+        )
+
+    def get_user_state(self, user_id: int) -> Optional[int]:
+        if user_id not in self._user_state_cache:
+            return None
+        return self._user_state_cache[user_id]
+
+    # TODO store in ctx.user_state
+    def set_user_state(self, user_id: int, state: Union[int, None]):
+        if not self._back_enabled:
+            return
+        if state is not None:
+            self._user_state_cache[user_id] = state
+        else:
+            del self._user_state_cache[user_id]
+
+    @staticmethod
+    @simplehandler
+    async def invalid(ctx: Context):
+        await ctx.reply(ctx.lang('invalid_input'), markup=IgnoreMarkup())
+        # return 0  # FIXME is this needed
+
+    @simplehandler
+    async def cancel(self, ctx: Context):
+        await start(ctx)
+        self.set_user_state(ctx.user_id, None)
+        return conversation.END
+
+    @simplehandler
+    async def back(self, ctx: Context):
+        cur_state = self.get_user_state(ctx.user_id)
+        if cur_state is None:
+            await start(ctx)
+            self.set_user_state(ctx.user_id, None)
+            return conversation.END
+
+        new_state = None
+        for seq in self.STATE_SEQS:
+            if cur_state in seq:
+                idx = seq.index(cur_state)
+                if idx > 0:
+                    return self.invoke(seq[idx-1], ctx)
+
+        if new_state is None:
+            raise RuntimeError('failed to determine state to go back to')
+
+    @classmethod
+    def add_cancel_button(cls, ctx: Context, buttons):
+        buttons.append([ctx.lang('cancel')])
+
+    @classmethod
+    def add_back_button(cls, ctx: Context, buttons):
+        # buttons.insert(0, [ctx.lang('back')])
+        buttons.append([ctx.lang('back')])
+
+    def reply(self,
+              ctx: Context,
+              state: Union[int, Enum],
+              text: str,
+              buttons: Optional[list],
+              with_cancel=False,
+              with_back=False,
+              buttons_lang_completed=False):
+
+        if buttons:
+            new_buttons = []
+            if not buttons_lang_completed:
+                for item in buttons:
+                    if isinstance(item, list):
+                        item = map(lambda s: ctx.lang(s), item)
+                        new_buttons.append(list(item))
+                    elif isinstance(item, str):
+                        new_buttons.append([ctx.lang(item)])
+                    else:
+                        raise ValueError('invalid type: ' + type(item))
+            else:
+                new_buttons = list(buttons)
+
+            buttons = None
+        else:
+            if with_cancel or with_back:
+                new_buttons = []
+            else:
+                new_buttons = None
+
+        if with_cancel:
+            self.add_cancel_button(ctx, new_buttons)
+        if with_back:
+            if not self._back_enabled:
+                raise AttributeError(f'back is not enabled for this conversation ({self.__class__.__name__})')
+            self.add_back_button(ctx, new_buttons)
+
+        markup = ReplyKeyboardMarkup(new_buttons, one_time_keyboard=True) if new_buttons else IgnoreMarkup()
+        ctx.reply(text, markup=markup)
+        self.set_user_state(ctx.user_id, state)
+        return state
+
+
+class LangConversation(conversation):
+    START, = range(1)
+
+    @conventer(START, command='lang')
+    async def entry(self, ctx: Context):
+        self._logger.debug(f'current language: {ctx.user_lang}')
+
+        buttons = []
+        for name in languages.values():
+            buttons.append(name)
+        markup = ReplyKeyboardMarkup([buttons, [ctx.lang('cancel')]], one_time_keyboard=False)
+
+        await ctx.reply(ctx.lang('select_language'), markup=markup)
+        return self.START
+
+    @convinput(START, messages=lang.languages)
+    async def input(self, ctx: Context):
+        selected_lang = None
+        for key, value in languages.items():
+            if value == ctx.text:
+                selected_lang = key
+                break
+
+        if selected_lang is None:
+            raise ValueError('could not find the language')
+
+        db.set_user_lang(ctx.user_id, selected_lang)
+        await ctx.reply(ctx.lang('saved'), markup=IgnoreMarkup())
+
+        return self.END
+
+
+def initialize():
+    global _user_filter
+    global _application
+    # global _updater
+    global _dispatcher
+
+    # init user_filter
+    _user_ids = config.app_config.get_user_ids()
+    if len(_user_ids) > 0:
+        _logger.info('allowed users: ' + str(_user_ids))
+        _user_filter = filters.User(_user_ids)
+    else:
+        _user_filter = filters.ALL  # not sure if this is correct
+
+    _application = Application.builder()\
+        .token(config.app_config.get('bot.token'))\
+        .connect_timeout(7)\
+        .read_timeout(6)\
+        .build()
+
+    # transparently log all messages
+    # _application.dispatcher.add_handler(MessageHandler(filters.ALL & _user_filter, _logging_message_handler), group=10)
+    # _application.dispatcher.add_handler(CallbackQueryHandler(_logging_callback_handler), group=10)
+
+
+def run(start_handler=None, any_handler=None):
+    global db
+    global _start_handler_ref
+
+    if not start_handler:
+        start_handler = _default_start_handler
+    if not any_handler:
+        any_handler = _default_any_handler
+    if not db:
+        db = BotDatabase()
+
+    _start_handler_ref = start_handler
+
+    _application.add_handler(LangConversation().get_handler(), group=0)
+    _application.add_handler(CommandHandler('start',
+                                            callback=simplehandler(start_handler),
+                                            filters=_user_filter))
+    _application.add_handler(MessageHandler(filters.ALL & _user_filter, any_handler))
+
+    _application.run_polling()
+
+
+def add_conversation(conv: conversation) -> None:
+    _application.add_handler(conv.get_handler(), group=0)
+
+
+def add_handler(h):
+    _application.add_handler(h, group=0)
+
+
+async def start(ctx: Context):
+    return await _start_handler_ref(ctx)
+
+
+async def _default_start_handler(ctx: Context):
+    if 'start_message' not in lang:
+        return await ctx.reply('Please define start_message or override start()')
+    await ctx.reply(ctx.lang('start_message'))
+
+
+@simplehandler
+async def _default_any_handler(ctx: Context):
+    if 'invalid_command' not in lang:
+        return await ctx.reply('Please define invalid_command or override any()')
+    await ctx.reply(ctx.lang('invalid_command'))
+
+
+def _logging_message_handler(update: Update, context: CallbackContext):
+    if _reporting:
+        _reporting.report(update.message)
+
+
+def _logging_callback_handler(update: Update, context: CallbackContext):
+    if _reporting:
+        _reporting.report(update.callback_query.message, text=update.callback_query.data)
+
+
+def enable_logging(bot_type: BotType):
+    api = WebApiClient(timeout=3)
+    api.enable_async()
+
+    global _reporting
+    _reporting = ReportingHelper(api, bot_type)
+
+
+def notify_all(text_getter: callable,
+               exclude: Tuple[int] = ()) -> None:
+    if 'notify_users' not in config['bot']:
+        _logger.error('notify_all() called but no notify_users directive found in the config')
+        return
+
+    for user_id in config['bot']['notify_users']:
+        if user_id in exclude:
+            continue
+
+        text = text_getter(db.get_user_lang(user_id))
+        _application.bot.send_message(chat_id=user_id,
+                                  text=text,
+                                  parse_mode='HTML')
+
+
+def notify_user(user_id: int, text: Union[str, Exception], **kwargs) -> None:
+    if isinstance(text, Exception):
+        text = exc2text(text)
+    _application.bot.send_message(chat_id=user_id,
+                              text=text,
+                              parse_mode='HTML',
+                              **kwargs)
+
+
+def send_photo(user_id, **kwargs):
+    _application.bot.send_photo(chat_id=user_id, **kwargs)
+
+
+def send_audio(user_id, **kwargs):
+    _application.bot.send_audio(chat_id=user_id, **kwargs)
+
+
+def send_file(user_id, **kwargs):
+    _application.bot.send_document(chat_id=user_id, **kwargs)
+
+
+def edit_message_text(user_id, message_id, *args, **kwargs):
+    _application.bot.edit_message_text(chat_id=user_id,
+                                   message_id=message_id,
+                                   parse_mode='HTML',
+                                   *args, **kwargs)
+
+
+def delete_message(user_id, message_id):
+    _application.bot.delete_message(chat_id=user_id, message_id=message_id)
+
+
+def set_database(_db: BotDatabase):
+    global db
+    db = _db
+
diff --git a/include/py/homekit/telegram/config.py b/include/py/homekit/telegram/config.py
new file mode 100644
index 0000000..4c7d74b
--- /dev/null
+++ b/include/py/homekit/telegram/config.py
@@ -0,0 +1,75 @@
+from ..config import ConfigUnit
+from typing import Optional, Union
+from abc import ABC
+from enum import Enum
+
+
+class TelegramUserListType(Enum):
+    USERS = 'users'
+    NOTIFY = 'notify_users'
+
+
+class TelegramUserIdsConfig(ConfigUnit):
+    NAME = 'telegram_user_ids'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'roottype': 'dict',
+            'type': 'integer'
+        }
+
+
+_user_ids_config = TelegramUserIdsConfig()
+
+
+def _user_id_mapper(user: Union[str, int]) -> int:
+    if isinstance(user, int):
+        return user
+    return _user_ids_config[user]
+
+
+class TelegramChatsConfig(ConfigUnit):
+    NAME = 'telegram_chats'
+
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'type': 'dict',
+            'schema': {
+                'id': {'type': 'string', 'required': True},
+                'token': {'type': 'string', 'required': True},
+            }
+        }
+
+
+class TelegramBotConfig(ConfigUnit, ABC):
+    @classmethod
+    def schema(cls) -> Optional[dict]:
+        return {
+            'bot': {
+                'type': 'dict',
+                'schema': {
+                    'token': {'type': 'string', 'required': True},
+                    TelegramUserListType.USERS: {**TelegramBotConfig._userlist_schema(), 'required': True},
+                    TelegramUserListType.NOTIFY: TelegramBotConfig._userlist_schema(),
+                }
+            }
+        }
+
+    @staticmethod
+    def _userlist_schema() -> dict:
+        return {'type': 'list', 'schema': {'type': ['string', 'int']}}
+
+    @staticmethod
+    def custom_validator(data):
+        for ult in TelegramUserListType:
+            users = data['bot'][ult.value]
+            for user in users:
+                if isinstance(user, str):
+                    if user not in _user_ids_config:
+                        raise ValueError(f'user {user} not found in {TelegramUserIdsConfig.NAME}')
+
+    def get_user_ids(self,
+                     ult: TelegramUserListType = TelegramUserListType.USERS) -> list[int]:
+        return list(map(_user_id_mapper, self['bot'][ult.value]))
\ No newline at end of file
diff --git a/include/py/homekit/telegram/telegram.py b/include/py/homekit/telegram/telegram.py
new file mode 100644
index 0000000..f42363e
--- /dev/null
+++ b/include/py/homekit/telegram/telegram.py
@@ -0,0 +1,49 @@
+import requests
+import logging
+
+from typing import Tuple
+from .config import TelegramChatsConfig
+
+_chats = TelegramChatsConfig()
+_logger = logging.getLogger(__name__)
+
+
+def send_message(text: str,
+                 chat: str,
+                 parse_mode: str = 'HTML',
+                 disable_web_page_preview: bool = False,):
+    data, token = _send_telegram_data(text, chat, parse_mode, disable_web_page_preview)
+    req = requests.post('https://api.telegram.org/bot%s/sendMessage' % token, data=data)
+    return req.json()
+
+
+def send_photo(filename: str, chat: str):
+    chat_data = _chats[chat]
+    data = {
+        'chat_id': chat_data['id'],
+    }
+    token = chat_data['token']
+
+    url = f'https://api.telegram.org/bot{token}/sendPhoto'
+    with open(filename, "rb") as fd:
+        req = requests.post(url, data=data, files={"photo": fd})
+    return req.json()
+
+
+def _send_telegram_data(text: str,
+                        chat: str,
+                        parse_mode: str = None,
+                        disable_web_page_preview: bool = False) -> Tuple[dict, str]:
+    chat_data = _chats[chat]
+    data = {
+        'chat_id': chat_data['id'],
+        'text': text
+    }
+
+    if parse_mode is not None:
+        data['parse_mode'] = parse_mode
+
+    if disable_web_page_preview:
+        data['disable_web_page_preview'] = 1
+
+    return data, chat_data['token']
diff --git a/include/py/homekit/temphum/__init__.py b/include/py/homekit/temphum/__init__.py
new file mode 100644
index 0000000..46d14e6
--- /dev/null
+++ b/include/py/homekit/temphum/__init__.py
@@ -0,0 +1 @@
+from .base import SensorType, BaseSensor
diff --git a/include/py/homekit/temphum/base.py b/include/py/homekit/temphum/base.py
new file mode 100644
index 0000000..602cab7
--- /dev/null
+++ b/include/py/homekit/temphum/base.py
@@ -0,0 +1,19 @@
+from abc import ABC
+from enum import Enum
+
+
+class BaseSensor(ABC):
+    def __init__(self, bus: int):
+        super().__init__()
+        self.bus = smbus.SMBus(bus)
+
+    def humidity(self) -> float:
+        pass
+
+    def temperature(self) -> float:
+        pass
+
+
+class SensorType(Enum):
+    Si7021 = 'si7021'
+    DHT12 = 'dht12'
\ No newline at end of file
diff --git a/include/py/homekit/temphum/i2c.py b/include/py/homekit/temphum/i2c.py
new file mode 100644
index 0000000..7d8e2e3
--- /dev/null
+++ b/include/py/homekit/temphum/i2c.py
@@ -0,0 +1,52 @@
+import abc
+import smbus
+
+from .base import BaseSensor, SensorType
+
+
+class I2CSensor(BaseSensor, abc.ABC):
+    def __init__(self, bus: int):
+        super().__init__()
+        self.bus = smbus.SMBus(bus)
+
+
+class DHT12(I2CSensor):
+    i2c_addr = 0x5C
+
+    def _measure(self):
+        raw = self.bus.read_i2c_block_data(self.i2c_addr, 0, 5)
+        if (raw[0] + raw[1] + raw[2] + raw[3]) & 0xff != raw[4]:
+            raise ValueError("checksum error")
+        return raw
+
+    def temperature(self) -> float:
+        raw = self._measure()
+        temp = raw[2] + (raw[3] & 0x7f) * 0.1
+        if raw[3] & 0x80:
+            temp *= -1
+        return temp
+
+    def humidity(self) -> float:
+        raw = self._measure()
+        return raw[0] + raw[1] * 0.1
+
+
+class Si7021(I2CSensor):
+    i2c_addr = 0x40
+
+    def temperature(self) -> float:
+        raw = self.bus.read_i2c_block_data(self.i2c_addr, 0xE3, 2)
+        return 175.72 * (raw[0] << 8 | raw[1]) / 65536.0 - 46.85
+
+    def humidity(self) -> float:
+        raw = self.bus.read_i2c_block_data(self.i2c_addr, 0xE5, 2)
+        return 125.0 * (raw[0] << 8 | raw[1]) / 65536.0 - 6.0
+
+
+def create_sensor(type: SensorType, bus: int) -> BaseSensor:
+    if type == SensorType.Si7021:
+        return Si7021(bus)
+    elif type == SensorType.DHT12:
+        return DHT12(bus)
+    else:
+        raise ValueError('unexpected sensor type')
diff --git a/include/py/homekit/util.py b/include/py/homekit/util.py
new file mode 100644
index 0000000..11e7116
--- /dev/null
+++ b/include/py/homekit/util.py
@@ -0,0 +1,255 @@
+from __future__ import annotations
+
+import json
+import socket
+import time
+import subprocess
+import traceback
+import logging
+import string
+import random
+import re
+
+from enum import Enum
+from datetime import datetime
+from typing import Optional, List
+from zlib import adler32
+
+logger = logging.getLogger(__name__)
+
+
+def validate_ipv4_or_hostname(address: str, raise_exception: bool = False) -> bool:
+    if re.match(r'^(\d{1,3}\.){3}\d{1,3}$', address):
+        parts = address.split('.')
+        if all(0 <= int(part) < 256 for part in parts):
+            return True
+        else:
+            if raise_exception:
+                raise ValueError(f"invalid IPv4 address: {address}")
+            return False
+
+    if re.match(r'^[a-zA-Z0-9.-]+$', address):
+        return True
+    else:
+        if raise_exception:
+            raise ValueError(f"invalid hostname: {address}")
+        return False
+
+
+def validate_mac_address(mac_address: str) -> bool:
+    mac_pattern = r'^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$'
+    if re.match(mac_pattern, mac_address):
+        return True
+    else:
+        return False
+
+
+class Addr:
+    host: str
+    port: Optional[int]
+
+    def __init__(self, host: str, port: Optional[int] = None):
+        self.host = host
+        self.port = port
+
+    @staticmethod
+    def fromstring(addr: str) -> Addr:
+        colons = addr.count(':')
+        if colons != 1:
+            raise ValueError('invalid host:port format')
+
+        if not colons:
+            host = addr
+            port= None
+        else:
+            host, port = addr.split(':')
+
+        validate_ipv4_or_hostname(host, raise_exception=True)
+
+        if port is not None:
+            port = int(port)
+            if not 0 <= port <= 65535:
+                raise ValueError(f'invalid port {port}')
+
+        return Addr(host, port)
+
+    def __str__(self):
+        buf = self.host
+        if self.port is not None:
+            buf += ':'+str(self.port)
+        return buf
+
+    def __iter__(self):
+        yield self.host
+        yield self.port
+
+
+# https://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks
+def chunks(lst, n):
+    """Yield successive n-sized chunks from lst."""
+    for i in range(0, len(lst), n):
+        yield lst[i:i + n]
+
+
+def json_serial(obj):
+    """JSON serializer for datetime objects"""
+    if isinstance(obj, datetime):
+        return obj.timestamp()
+    if isinstance(obj, Enum):
+        return obj.value
+    raise TypeError("Type %s not serializable" % type(obj))
+
+
+def stringify(v) -> str:
+    return json.dumps(v, separators=(',', ':'), default=json_serial)
+
+
+def ipv4_valid(ip: str) -> bool:
+    try:
+        socket.inet_aton(ip)
+        return True
+    except socket.error:
+        return False
+
+
+def strgen(n: int):
+    return ''.join(random.choices(string.ascii_letters + string.digits, k=n))
+
+
+class MySimpleSocketClient:
+    host: str
+    port: int
+
+    def __init__(self, host: str, port: int):
+        self.host = host
+        self.port = port
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.sock.connect((self.host, self.port))
+        self.sock.settimeout(5)
+
+    def __del__(self):
+        self.sock.close()
+
+    def write(self, line: str) -> None:
+        self.sock.sendall((line + '\r\n').encode())
+
+    def read(self) -> str:
+        buf = bytearray()
+        while True:
+            buf.extend(self.sock.recv(256))
+            if b'\r\n' in buf:
+                break
+
+        response = buf.decode().strip()
+        return response
+
+
+def send_datagram(message: str, addr: Addr) -> None:
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.sendto(message.encode(), addr)
+
+
+def format_tb(exc) -> Optional[List[str]]:
+    tb = traceback.format_tb(exc.__traceback__)
+    if not tb:
+        return None
+
+    tb = list(map(lambda s: s.strip(), tb))
+    tb.reverse()
+    if tb[0][-1:] == ':':
+        tb[0] = tb[0][:-1]
+
+    return tb
+
+
+class ChildProcessInfo:
+    pid: int
+    cmd: str
+
+    def __init__(self,
+                 pid: int,
+                 cmd: str):
+        self.pid = pid
+        self.cmd = cmd
+
+
+def find_child_processes(ppid: int) -> List[ChildProcessInfo]:
+    p = subprocess.run(['pgrep', '-P', str(ppid), '--list-full'], capture_output=True)
+    if p.returncode != 0:
+        raise OSError(f'pgrep returned {p.returncode}')
+
+    children = []
+
+    lines = p.stdout.decode().strip().split('\n')
+    for line in lines:
+        try:
+            space_idx = line.index(' ')
+        except ValueError as exc:
+            logger.exception(exc)
+            continue
+
+        pid = int(line[0:space_idx])
+        cmd = line[space_idx+1:]
+
+        children.append(ChildProcessInfo(pid, cmd))
+
+    return children
+
+
+class Stopwatch:
+    elapsed: float
+    time_started: Optional[float]
+
+    def __init__(self):
+        self.elapsed = 0
+        self.time_started = None
+
+    def go(self):
+        if self.time_started is not None:
+            raise StopwatchError('stopwatch was already started')
+
+        self.time_started = time.time()
+
+    def pause(self):
+        if self.time_started is None:
+            raise StopwatchError('stopwatch was paused')
+
+        self.elapsed += time.time() - self.time_started
+        self.time_started = None
+
+    def get_elapsed_time(self):
+        elapsed = self.elapsed
+        if self.time_started is not None:
+            elapsed += time.time() - self.time_started
+        return elapsed
+
+    def reset(self):
+        self.time_started = None
+        self.elapsed = 0
+
+    def is_paused(self):
+        return self.time_started is None
+
+
+class StopwatchError(RuntimeError):
+    pass
+
+
+def filesize_fmt(num, suffix="B") -> str:
+    for unit in ["", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi"]:
+        if abs(num) < 1024.0:
+            return f"{num:3.1f} {unit}{suffix}"
+        num /= 1024.0
+    return f"{num:.1f} Yi{suffix}"
+
+
+class HashableEnum(Enum):
+    def hash(self) -> int:
+        return adler32(self.name.encode())
+
+
+def next_tick_gen(freq):
+    t = time.time()
+    while True:
+        t += freq
+        yield max(t - time.time(), 0)
\ No newline at end of file
diff --git a/include/py/pyA20/__init__.pyi b/include/py/pyA20/__init__.pyi
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/include/py/pyA20/__init__.pyi
diff --git a/include/py/pyA20/gpio/connector.pyi b/include/py/pyA20/gpio/connector.pyi
new file mode 100644
index 0000000..12b2b6e
--- /dev/null
+++ b/include/py/pyA20/gpio/connector.pyi
@@ -0,0 +1,2 @@
+gpio1 = 0
+LED = 0
\ No newline at end of file
diff --git a/include/py/pyA20/gpio/gpio.pyi b/include/py/pyA20/gpio/gpio.pyi
new file mode 100644
index 0000000..225fcbe
--- /dev/null
+++ b/include/py/pyA20/gpio/gpio.pyi
@@ -0,0 +1,24 @@
+HIGH = 1
+LOW = 0
+INPUT = 0
+OUTPUT = 0
+PULLUP = 0
+PULLDOWN = 0
+
+def init():
+    pass
+
+def setcfg(gpio: int, cfg: int):
+    pass
+
+def getcfg(gpio: int):
+    pass
+
+def output(gpio: int, value: int):
+    pass
+
+def pullup(gpio: int, pull: int):
+    pass
+
+def input(gpio: int):
+    pass
\ No newline at end of file
diff --git a/include/py/pyA20/gpio/port.pyi b/include/py/pyA20/gpio/port.pyi
new file mode 100644
index 0000000..17f69fe
--- /dev/null
+++ b/include/py/pyA20/gpio/port.pyi
@@ -0,0 +1,36 @@
+# these are not real values, just placeholders
+
+PA12 = 0
+PA11 = 0
+PA6 = 0
+
+PA1 = 0
+PA0 = 0
+
+PA3 = 0
+PC0 = 0
+PC1 = 0
+PC2 = 0
+PA19 = 0
+PA7 = 0
+PA8 = 0
+PA9 = 0
+PA10 = 0
+PA20 = 0
+
+PA13 = 0
+PA14 = 0
+PD14 = 0
+PC4 = 0
+PC7 = 0
+PA2 = 0
+PC3 = 0
+PA21 = 0
+PA18 = 0
+PG8 = 0
+PG9 = 0
+PG6 = 0
+PG7 = 0
+
+POWER_LED = 0
+STATUS_LED = 0
\ No newline at end of file
diff --git a/include/py/pyA20/port.pyi b/include/py/pyA20/port.pyi
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/include/py/pyA20/port.pyi
diff --git a/include/py/syncleo/__init__.py b/include/py/syncleo/__init__.py
new file mode 100644
index 0000000..32563a5
--- /dev/null
+++ b/include/py/syncleo/__init__.py
@@ -0,0 +1,12 @@
+# Polaris PWK 1725CGLD "smart" kettle python library
+# --------------------------------------------------
+# Copyright (C) Evgeny Zinoviev, 2022
+# License: BSD-3c
+
+from .kettle import Kettle, DeviceListener
+from .protocol import (
+    PowerType,
+    IncomingMessageListener,
+    ConnectionStatusListener,
+    ConnectionStatus
+)
diff --git a/include/py/syncleo/kettle.py b/include/py/syncleo/kettle.py
new file mode 100644
index 0000000..d6e0dd6
--- /dev/null
+++ b/include/py/syncleo/kettle.py
@@ -0,0 +1,243 @@
+# Polaris PWK 1725CGLD smart kettle python library
+# ------------------------------------------------
+# Copyright (C) Evgeny Zinoviev, 2022
+# License: BSD-3c
+
+from __future__ import annotations
+
+import threading
+import logging
+import zeroconf
+
+from abc import abstractmethod
+from ipaddress import ip_address, IPv4Address, IPv6Address
+from typing import Optional, List, Union
+
+from .protocol import (
+    UDPConnection,
+    ModeMessage,
+    TargetTemperatureMessage,
+    PowerType,
+    ConnectionStatus,
+    ConnectionStatusListener,
+    WrappedMessage
+)
+
+
+class DeviceDiscover(threading.Thread, zeroconf.ServiceListener):
+    si: Optional[zeroconf.ServiceInfo]
+    _mac: str
+    _sb: Optional[zeroconf.ServiceBrowser]
+    _zc: Optional[zeroconf.Zeroconf]
+    _listeners: List[DeviceListener]
+    _valid_addresses: List[Union[IPv4Address, IPv6Address]]
+    _only_ipv4: bool
+
+    def __init__(self, mac: str,
+                 listener: Optional[DeviceListener] = None,
+                 only_ipv4=True):
+        super().__init__()
+        self.si = None
+        self._mac = mac
+        self._zc = None
+        self._sb = None
+        self._only_ipv4 = only_ipv4
+        self._valid_addresses = []
+        self._listeners = []
+        if isinstance(listener, DeviceListener):
+            self._listeners.append(listener)
+        self._logger = logging.getLogger(f'{__name__}.{self.__class__.__name__}')
+
+    def add_listener(self, listener: DeviceListener):
+        if listener not in self._listeners:
+            self._listeners.append(listener)
+        else:
+            self._logger.warning(f'add_listener: listener {listener} already in the listeners list')
+
+    def set_info(self, info: zeroconf.ServiceInfo):
+        valid_addresses = self._get_valid_addresses(info)
+        if not valid_addresses:
+            raise ValueError('no valid addresses')
+        self._valid_addresses = valid_addresses
+        self.si = info
+        for f in self._listeners:
+            try:
+                f.device_updated()
+            except Exception as exc:
+                self._logger.error(f'set_info: error while calling device_updated on {f}')
+                self._logger.exception(exc)
+
+    def add_service(self, zc: zeroconf.Zeroconf, type_: str, name: str) -> None:
+        self._add_update_service('add_service', zc, type_, name)
+
+    def update_service(self, zc: zeroconf.Zeroconf, type_: str, name: str) -> None:
+        self._add_update_service('update_service', zc, type_, name)
+
+    def _add_update_service(self, method: str, zc: zeroconf.Zeroconf, type_: str, name: str) -> None:
+        info = zc.get_service_info(type_, name)
+        if name.startswith(f'{self._mac}.'):
+            self._logger.info(f'{method}: type={type_} name={name}')
+            try:
+                self.set_info(info)
+            except ValueError as exc:
+                self._logger.error(f'{method}: rejected: {str(exc)}')
+        else:
+            self._logger.debug(f'{method}: mac not matched: {info}')
+
+    def remove_service(self, zc: zeroconf.Zeroconf, type_: str, name: str) -> None:
+        if name.startswith(f'{self._mac}.'):
+            self._logger.info(f'remove_service: type={type_} name={name}')
+            # TODO what to do here?!
+
+    def run(self):
+        self._logger.debug('starting zeroconf service browser')
+        ip_version = zeroconf.IPVersion.V4Only if self._only_ipv4 else zeroconf.IPVersion.All
+        self._zc = zeroconf.Zeroconf(ip_version=ip_version)
+        self._sb = zeroconf.ServiceBrowser(self._zc, "_syncleo._udp.local.", self)
+        self._sb.join()
+
+    def stop(self):
+        if self._sb:
+            try:
+                self._sb.cancel()
+            except RuntimeError:
+                pass
+            self._sb = None
+        self._zc.close()
+        self._zc = None
+
+    def _get_valid_addresses(self, si: zeroconf.ServiceInfo) -> List[Union[IPv4Address, IPv6Address]]:
+        valid = []
+        for addr in map(ip_address, si.addresses):
+            if self._only_ipv4 and not isinstance(addr, IPv4Address):
+                continue
+            if isinstance(addr, IPv4Address) and str(addr).startswith('169.254.'):
+                continue
+            valid.append(addr)
+        return valid
+
+    @property
+    def pubkey(self) -> bytes:
+        return bytes.fromhex(self.si.properties[b'public'].decode())
+
+    @property
+    def curve(self) -> int:
+        return int(self.si.properties[b'curve'].decode())
+
+    @property
+    def addr(self) -> Union[IPv4Address, IPv6Address]:
+        return self._valid_addresses[0]
+
+    @property
+    def port(self) -> int:
+        return int(self.si.port)
+
+    @property
+    def protocol(self) -> int:
+        return int(self.si.properties[b'protocol'].decode())
+
+
+class DeviceListener:
+    @abstractmethod
+    def device_updated(self):
+        pass
+
+
+class Kettle(DeviceListener, ConnectionStatusListener):
+    mac: str
+    device: Optional[DeviceDiscover]
+    device_token: str
+    conn: Optional[UDPConnection]
+    conn_status: Optional[ConnectionStatus]
+    _read_timeout: Optional[int]
+    _logger: logging.Logger
+    _find_evt: threading.Event
+
+    def __init__(self, mac: str, device_token: str, read_timeout: Optional[int] = None):
+        super().__init__()
+        self.mac = mac
+        self.device = None
+        self.device_token = device_token
+        self.conn = None
+        self.conn_status = None
+        self._read_timeout = read_timeout
+        self._find_evt = threading.Event()
+        self._logger = logging.getLogger(f'{__name__}.{self.__class__.__name__}')
+
+    def device_updated(self):
+        self._find_evt.set()
+        self._logger.info(f'device updated, service info: {self.device.si}')
+
+    def connection_status_updated(self, status: ConnectionStatus):
+        self.conn_status = status
+
+    def discover(self, wait=True, timeout=None, listener=None) -> Optional[zeroconf.ServiceInfo]:
+        do_start = False
+        if not self.device:
+            self.device = DeviceDiscover(self.mac, listener=self, only_ipv4=True)
+            do_start = True
+            self._logger.debug('discover: started device discovery')
+        else:
+            self._logger.warning('discover: already started')
+
+        if listener is not None:
+            self.device.add_listener(listener)
+
+        if do_start:
+            self.device.start()
+
+        if wait:
+            self._find_evt.clear()
+            try:
+                self._find_evt.wait(timeout=timeout)
+            except KeyboardInterrupt:
+                self.device.stop()
+                return None
+            return self.device.si
+
+    def start_server_if_needed(self,
+                               incoming_message_listener=None,
+                               connection_status_listener=None):
+        if self.conn:
+            self._logger.warning('start_server_if_needed: server is already started!')
+            self.conn.set_address(self.device.addr, self.device.port)
+            self.conn.set_device_pubkey(self.device.pubkey)
+            return
+
+        assert self.device.curve == 29, f'curve type {self.device.curve} is not implemented'
+        assert self.device.protocol == 2, f'protocol {self.device.protocol} is not supported'
+
+        kw = {}
+        if self._read_timeout is not None:
+            kw['read_timeout'] = self._read_timeout
+        self.conn = UDPConnection(addr=self.device.addr,
+                                  port=self.device.port,
+                                  device_pubkey=self.device.pubkey,
+                                  device_token=bytes.fromhex(self.device_token), **kw)
+        if incoming_message_listener:
+            self.conn.add_incoming_message_listener(incoming_message_listener)
+
+        self.conn.add_connection_status_listener(self)
+        if connection_status_listener:
+            self.conn.add_connection_status_listener(connection_status_listener)
+
+        self.conn.start()
+
+    def stop_all(self):
+        # when we stop server, we should also stop device discovering service
+        if self.conn:
+            self.conn.interrupted = True
+            self.conn = None
+        self.device.stop()
+        self.device = None
+
+    def is_connected(self) -> bool:
+        return self.conn is not None and self.conn_status == ConnectionStatus.CONNECTED
+
+    def set_power(self, power_type: PowerType, callback: callable):
+        message = ModeMessage(power_type)
+        self.conn.enqueue_message(WrappedMessage(message, handler=callback, ack=True))
+
+    def set_target_temperature(self, temp: int, callback: callable):
+        message = TargetTemperatureMessage(temp)
+        self.conn.enqueue_message(WrappedMessage(message, handler=callback, ack=True))
diff --git a/include/py/syncleo/protocol.py b/include/py/syncleo/protocol.py
new file mode 100644
index 0000000..36a1a8f
--- /dev/null
+++ b/include/py/syncleo/protocol.py
@@ -0,0 +1,1169 @@
+# Polaris PWK 1725CGLD "smart" kettle python library
+# --------------------------------------------------
+# Copyright (C) Evgeny Zinoviev, 2022
+# License: BSD-3c
+
+from __future__ import annotations
+
+import logging
+import socket
+import random
+import struct
+import threading
+import time
+
+from abc import abstractmethod, ABC
+from enum import Enum, auto
+from typing import Union, Optional, Dict, Tuple, List
+from ipaddress import IPv4Address, IPv6Address
+
+import cryptography.hazmat.primitives._serialization as srlz
+
+from cryptography.hazmat.primitives.asymmetric.x25519 import X25519PrivateKey, X25519PublicKey
+from cryptography.hazmat.primitives import ciphers, padding, hashes
+from cryptography.hazmat.primitives.ciphers import algorithms, modes
+
+ReprDict = Dict[str, Union[str, int, float, bool]]
+_logger = logging.getLogger(__name__)
+
+PING_FREQUENCY = 3
+RESEND_ATTEMPTS = 5
+ERROR_TIMEOUT = 15
+MESSAGE_QUEUE_REMOVE_DELAY = 13  # after what time to delete (and pass False to handlers, if needed) messages with phase=DONE from queue
+DISCONNECT_TIMEOUT = 15
+
+
+def safe_callback_call(f: callable,
+                       *args,
+                       logger: logging.Logger = None,
+                       error_message: str = None):
+    try:
+        return f(*args)
+    except Exception as exc:
+        logger.error(f'{error_message}, see exception below:')
+        logger.exception(exc)
+    return None
+
+
+# drop-in replacement for java.lang.System.arraycopy
+# TODO: rewrite
+def arraycopy(src, src_pos, dest, dest_pos, length):
+    for i in range(length):
+        dest[i + dest_pos] = src[i + src_pos]
+
+
+# "convert" unsigned byte to signed
+def u8_to_s8(b: int) -> int:
+    return struct.unpack('b', bytes([b]))[0]
+
+
+class PowerType(Enum):
+    OFF = 0  # turn off
+    ON = 1  # turn on, set target temperature to 100
+    CUSTOM = 3  # turn on, allows custom target temperature
+    # MYSTERY_MODE = 2  # don't know what 2 means, needs testing
+    # update: if I set it to '2', it just resets to '0'
+
+
+# low-level protocol structures
+# -----------------------------
+
+class FrameType(Enum):
+    ACK = 0
+    CMD = 1
+    AUX = 2
+    NAK = 3
+
+
+class FrameHead:
+    seq: Optional[int]  # u8
+    type: FrameType  # u8
+    length: int  # u16. This is the length of FrameItem's payload
+
+    @staticmethod
+    def from_bytes(buf: bytes) -> FrameHead:
+        seq, ft, length = struct.unpack('<BBH', buf)
+        return FrameHead(seq, FrameType(ft), length)
+
+    def __init__(self,
+                 seq: Optional[int],
+                 frame_type: FrameType,
+                 length: Optional[int] = None):
+        self.seq = seq
+        self.type = frame_type
+        self.length = length or 0
+
+    def pack(self) -> bytes:
+        assert self.length != 0, "FrameHead.length has not been set"
+        assert self.seq is not None, "FrameHead.seq has not been set"
+        return struct.pack('<BBH', self.seq, self.type.value, self.length)
+
+
+class FrameItem:
+    head: FrameHead
+    payload: bytes
+
+    def __init__(self, head: FrameHead, payload: Optional[bytes] = None):
+        self.head = head
+        self.payload = payload
+
+    def setpayload(self, payload: Union[bytes, bytearray]):
+        if isinstance(payload, bytearray):
+            payload = bytes(payload)
+        self.payload = payload
+        self.head.length = len(payload)
+
+    def pack(self) -> bytes:
+        ba = bytearray(self.head.pack())
+        ba.extend(self.payload)
+        return bytes(ba)
+
+
+# high-level wrappers around FrameItem
+# ------------------------------------
+
+class MessagePhase(Enum):
+    WAITING = 0
+    SENT = 1
+    DONE = 2
+
+
+class Message:
+    frame: Optional[FrameItem]
+    id: int
+
+    _global_id = 0
+
+    def __init__(self):
+        self.frame = None
+
+        # global internal message id, only useful for debugging purposes
+        self.id = self.next_id()
+
+    def __repr__(self):
+        return f'<{self.__class__.__name__} id={self.id} seq={self.frame.head.seq}>'
+
+    @staticmethod
+    def next_id():
+        _id = Message._global_id
+        Message._global_id = (Message._global_id + 1) % 100000
+        return _id
+
+    @staticmethod
+    def from_encrypted(buf: bytes, inkey: bytes, outkey: bytes) -> Message:
+        _logger.debug(f'Message:from_encrypted: buf={buf.hex()}')
+
+        assert len(buf) >= 4, 'invalid size'
+        head = FrameHead.from_bytes(buf[:4])
+
+        assert len(buf) == head.length + 4, f'invalid buf size ({len(buf)} != {head.length})'
+        payload = buf[4:]
+        b = head.seq
+
+        j = b & 0xF
+        k = b >> 4 & 0xF
+
+        key = bytearray(len(inkey))
+        arraycopy(inkey, j, key, 0, len(inkey) - j)
+        arraycopy(inkey, 0, key, len(inkey) - j, j)
+
+        iv = bytearray(len(outkey))
+        arraycopy(outkey, k, iv, 0, len(outkey) - k)
+        arraycopy(outkey, 0, iv, len(outkey) - k, k)
+
+        cipher = ciphers.Cipher(algorithms.AES(key), modes.CBC(iv))
+        decryptor = cipher.decryptor()
+        decrypted_data = decryptor.update(payload) + decryptor.finalize()
+
+        unpadder = padding.PKCS7(algorithms.AES.block_size).unpadder()
+        decrypted_data = unpadder.update(decrypted_data)
+        decrypted_data += unpadder.finalize()
+
+        assert len(decrypted_data) != 0, 'decrypted data is null'
+        assert head.seq == decrypted_data[0], f'decrypted seq mismatch {head.seq} != {decrypted_data[0]}'
+
+        # _logger.debug('Message.from_encrypted: plaintext: '+decrypted_data.hex())
+
+        if head.type == FrameType.ACK:
+            return AckMessage(head.seq)
+
+        elif head.type == FrameType.NAK:
+            return NakMessage(head.seq)
+
+        elif head.type == FrameType.AUX:
+            # TODO implement AUX
+            raise NotImplementedError('FrameType AUX is not yet implemented')
+
+        elif head.type == FrameType.CMD:
+            type = decrypted_data[1]
+            data = decrypted_data[2:]
+
+            cl = UnknownMessage
+
+            subclasses = [cl for cl in CmdIncomingMessage.__subclasses__() if cl is not SimpleBooleanMessage]
+            subclasses.extend(SimpleBooleanMessage.__subclasses__())
+
+            for _cl in subclasses:
+                # `UnknownMessage` is a special class that holds a packed command that we don't recognize.
+                # It will be used anyway if we don't find a match, so skip it here
+                if _cl == UnknownMessage:
+                    continue
+
+                if _cl.TYPE == type:
+                    cl = _cl
+                    break
+
+            m = cl.from_packed_data(data, seq=head.seq)
+            if isinstance(m, UnknownMessage):
+                m.set_type(type)
+            return m
+
+        else:
+            raise NotImplementedError(f'Unexpected frame type: {head.type}')
+
+    def pack_data(self) -> bytes:
+        return b''
+
+    @property
+    def seq(self) -> Union[int, None]:
+        try:
+            return self.frame.head.seq
+        except:
+            return None
+
+    @seq.setter
+    def seq(self, seq: int):
+        self.frame.head.seq = seq
+
+    def encrypt(self, outkey: bytes, inkey: bytes, token: bytes, pubkey: bytes):
+        assert self.frame is not None
+
+        data = self._get_data_to_encrypt()
+        assert data is not None
+
+        b = self.frame.head.seq
+        i = b & 0xf
+        j = b >> 4 & 0xf
+
+        outkey = bytearray(outkey)
+
+        l = len(outkey)
+        key = bytearray(l)
+
+        arraycopy(outkey, i, key, 0, l-i)
+        arraycopy(outkey, 0, key, l-i, i)
+
+        inkey = bytearray(inkey)
+
+        l = len(inkey)
+        iv = bytearray(l)
+
+        arraycopy(inkey, j, iv, 0, l-j)
+        arraycopy(inkey, 0, iv, l-j, j)
+
+        cipher = ciphers.Cipher(algorithms.AES(key), modes.CBC(iv))
+        encryptor = cipher.encryptor()
+
+        newdata = bytearray(len(data)+1)
+        newdata[0] = b
+
+        arraycopy(data, 0, newdata, 1, len(data))
+
+        newdata = bytes(newdata)
+        _logger.debug('frame payload to be encrypted: ' + newdata.hex())
+
+        padder = padding.PKCS7(algorithms.AES.block_size).padder()
+        ciphertext = bytearray()
+        ciphertext.extend(encryptor.update(padder.update(newdata) + padder.finalize()))
+        ciphertext.extend(encryptor.finalize())
+
+        self.frame.setpayload(ciphertext)
+
+    def _get_data_to_encrypt(self) -> bytes:
+        return self.pack_data()
+
+
+class AckMessage(Message, ABC):
+    def __init__(self, seq: Optional[int] = None):
+        super().__init__()
+        self.frame = FrameItem(FrameHead(seq, FrameType.ACK, None))
+
+
+class NakMessage(Message, ABC):
+    def __init__(self, seq: Optional[int] = None):
+        super().__init__()
+        self.frame = FrameItem(FrameHead(seq, FrameType.NAK, None))
+
+
+class CmdMessage(Message):
+    type: Optional[int]
+    data: bytes
+
+    TYPE = None
+
+    def _get_data_to_encrypt(self) -> bytes:
+        buf = bytearray()
+        buf.append(self.get_type())
+        buf.extend(self.pack_data())
+        return bytes(buf)
+
+    def __init__(self, seq: Optional[int] = None):
+        super().__init__()
+        self.frame = FrameItem(FrameHead(seq, FrameType.CMD))
+        self.data = b''
+
+    def _repr_fields(self) -> ReprDict:
+        return {
+            'cmd': self.get_type()
+        }
+
+    def __repr__(self):
+        params = [
+            __name__+'.'+self.__class__.__name__,
+            f'id={self.id}',
+            f'seq={self.seq}'
+        ]
+        fields = self._repr_fields()
+        if fields:
+            for k, v in fields.items():
+                params.append(f'{k}={v}')
+        elif self.data:
+            params.append(f'data={self.data.hex()}')
+        return '<'+' '.join(params)+'>'
+
+    def get_type(self) -> int:
+        return self.__class__.TYPE
+
+
+class CmdIncomingMessage(CmdMessage):
+    @staticmethod
+    @abstractmethod
+    def from_packed_data(cls, data: bytes, seq: Optional[int] = None):
+        pass
+
+    @abstractmethod
+    def _repr_fields(self) -> ReprDict:
+        pass
+
+
+class CmdOutgoingMessage(CmdMessage):
+    @abstractmethod
+    def pack_data(self) -> bytes:
+        return b''
+
+
+class ModeMessage(CmdOutgoingMessage, CmdIncomingMessage):
+    TYPE = 1
+
+    pt: PowerType
+
+    def __init__(self, power_type: PowerType, seq: Optional[int] = None):
+        super().__init__(seq)
+        self.pt = power_type
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> ModeMessage:
+        assert len(data) == 1, 'data size expected to be 1'
+        mode, = struct.unpack('B', data)
+        return ModeMessage(PowerType(mode), seq=seq)
+
+    def pack_data(self) -> bytes:
+        return self.pt.value.to_bytes(1, byteorder='little')
+
+    def _repr_fields(self) -> ReprDict:
+        return {'mode': self.pt.name}
+
+
+class TargetTemperatureMessage(CmdOutgoingMessage, CmdIncomingMessage):
+    temperature: int
+
+    TYPE = 2
+
+    def __init__(self, temp: int, seq: Optional[int] = None):
+        super().__init__(seq)
+        self.temperature = temp
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> TargetTemperatureMessage:
+        assert len(data) == 2, 'data size expected to be 2'
+        nat, frac = struct.unpack('BB', data)
+        temp = int(nat + (frac / 100))
+        return TargetTemperatureMessage(temp, seq=seq)
+
+    def pack_data(self) -> bytes:
+        return bytes([self.temperature, 0])
+
+    def _repr_fields(self) -> ReprDict:
+        return {'temperature': self.temperature}
+
+
+class PingMessage(CmdIncomingMessage, CmdOutgoingMessage):
+    TYPE = 255
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> PingMessage:
+        assert len(data) == 0, 'no data expected'
+        return PingMessage(seq=seq)
+
+    def pack_data(self) -> bytes:
+        return b''
+
+    def _repr_fields(self) -> ReprDict:
+        return {}
+
+
+# This is the first protocol message. Sent by a client.
+# Kettle usually ACKs this, but sometimes i don't get any ACK and the very next message is HandshakeResponseMessage.
+class HandshakeMessage(CmdMessage):
+    TYPE = 0
+
+    def encrypt(self,
+                outkey: bytes,
+                inkey: bytes,
+                token: bytes,
+                pubkey: bytes):
+        cipher = ciphers.Cipher(algorithms.AES(outkey), modes.CBC(inkey))
+        encryptor = cipher.encryptor()
+
+        ciphertext = bytearray()
+        ciphertext.extend(encryptor.update(token))
+        ciphertext.extend(encryptor.finalize())
+
+        pld = bytearray()
+        pld.append(0)
+        pld.extend(pubkey)
+        pld.extend(ciphertext)
+
+        self.frame.setpayload(pld)
+
+
+# Kettle either sends this right after the handshake, of first it ACKs the handshake then sends this.
+class HandshakeResponseMessage(CmdIncomingMessage):
+    TYPE = 0
+
+    protocol: int
+    fw_major: int
+    fw_minor: int
+    mode: int
+    token: bytes
+
+    def __init__(self,
+                 protocol: int,
+                 fw_major: int,
+                 fw_minor: int,
+                 mode: int,
+                 token: bytes,
+                 seq: Optional[int] = None):
+        super().__init__(seq)
+        self.protocol = protocol
+        self.fw_major = fw_major
+        self.fw_minor = fw_minor
+        self.mode = mode
+        self.token = token
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> HandshakeResponseMessage:
+        protocol, fw_major, fw_minor, mode = struct.unpack('<HBBB', data[:5])
+        return HandshakeResponseMessage(protocol, fw_major, fw_minor, mode, token=data[5:], seq=seq)
+
+    def _repr_fields(self) -> ReprDict:
+        return {
+            'protocol': self.protocol,
+            'fw': f'{self.fw_major}.{self.fw_minor}',
+            'mode': self.mode,
+            'token': self.token.hex()
+        }
+
+
+# Apparently, some hardware info.
+# On the other hand, if you look at com.syncleiot.iottransport.commands.CmdHardware, its mqtt topic says "mcu_firmware".
+# My device returns 1.1.1. The kettle uses on ESP8266 ESP-12F MCU under the hood (or, more precisely, under a piece of
+# cheap plastic), so maybe 1.1.1 is some MCU ROM version.
+class DeviceHardwareMessage(CmdIncomingMessage):
+    TYPE = 143  # -113
+
+    hw: List[int]
+
+    def __init__(self, hw: List[int], seq: Optional[int] = None):
+        super().__init__(seq)
+        self.hw = hw
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> DeviceHardwareMessage:
+        assert len(data) == 3, 'invalid data size, expected 3'
+        hw = list(struct.unpack('<BBB', data))
+        return DeviceHardwareMessage(hw, seq=seq)
+
+    def _repr_fields(self) -> ReprDict:
+        return {'device_hardware': '.'.join(map(str, self.hw))}
+
+
+# This message is sent by kettle right after the HandshakeMessageResponse.
+# The diagnostic data is supposed to be sent to vendor, which we, obviously, not going to do.
+# So just ACK and skip it.
+class DeviceDiagnosticMessage(CmdIncomingMessage):
+    TYPE = 145  # -111
+
+    diag_data: bytes
+
+    def __init__(self, diag_data: bytes, seq: Optional[int] = None):
+        super().__init__(seq)
+        self.diag_data = diag_data
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> DeviceDiagnosticMessage:
+        return DeviceDiagnosticMessage(diag_data=data, seq=seq)
+
+    def _repr_fields(self) -> ReprDict:
+        return {'diag_data': self.diag_data.hex()}
+
+
+class SimpleBooleanMessage(ABC, CmdIncomingMessage):
+    value: bool
+
+    def __init__(self, value: bool, seq: Optional[int] = None):
+        super().__init__(seq)
+        self.value = value
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq: Optional[int] = None):
+        assert len(data) == 1, 'invalid data size, expected 1'
+        enabled, = struct.unpack('<B', data)
+        return cls(value=enabled == 1, seq=seq)
+
+    @abstractmethod
+    def _repr_fields(self) -> ReprDict:
+        pass
+
+
+class AccessControlMessage(SimpleBooleanMessage):
+    TYPE = 133  # -123
+
+    def _repr_fields(self) -> ReprDict:
+        return {'acl_enabled': self.value}
+
+
+class ErrorMessage(SimpleBooleanMessage):
+    TYPE = 7
+
+    def _repr_fields(self) -> ReprDict:
+        return {'error': self.value}
+
+
+class ChildLockMessage(SimpleBooleanMessage):
+    TYPE = 30
+
+    def _repr_fields(self) -> ReprDict:
+        return {'child_lock': self.value}
+
+
+class VolumeMessage(SimpleBooleanMessage):
+    TYPE = 9
+
+    def _repr_fields(self) -> ReprDict:
+        return {'volume': self.value}
+
+
+class BacklightMessage(SimpleBooleanMessage):
+    TYPE = 28
+
+    def _repr_fields(self) -> ReprDict:
+        return {'backlight': self.value}
+
+
+class CurrentTemperatureMessage(CmdIncomingMessage):
+    TYPE = 20
+
+    current_temperature: int
+
+    def __init__(self, temp: int, seq: Optional[int] = None):
+        super().__init__(seq)
+        self.current_temperature = temp
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> CurrentTemperatureMessage:
+        assert len(data) == 2, 'data size expected to be 2'
+        nat, frac = struct.unpack('BB', data)
+        temp = int(nat + (frac / 100))
+        return CurrentTemperatureMessage(temp, seq=seq)
+
+    def pack_data(self) -> bytes:
+        return bytes([self.current_temperature, 0])
+
+    def _repr_fields(self) -> ReprDict:
+        return {'current_temperature': self.current_temperature}
+
+
+class UnknownMessage(CmdIncomingMessage):
+    type: Optional[int]
+    data: bytes
+
+    def __init__(self, data: bytes, **kwargs):
+        super().__init__(**kwargs)
+        self.type = None
+        self.data = data
+
+    @classmethod
+    def from_packed_data(cls, data: bytes, seq=0) -> UnknownMessage:
+        return UnknownMessage(data, seq=seq)
+
+    def set_type(self, type: int):
+        self.type = type
+
+    def get_type(self) -> int:
+        return self.type
+
+    def _repr_fields(self) -> ReprDict:
+        return {
+            'type': self.type,
+            'data': self.data.hex()
+        }
+
+
+class WrappedMessage:
+    _message: Message
+    _handler: Optional[callable]
+    _validator: Optional[callable]
+    _logger: Optional[logging.Logger]
+    _phase: MessagePhase
+    _phase_update_time: float
+
+    def __init__(self,
+                 message: Message,
+                 handler: Optional[callable] = None,
+                 validator: Optional[callable] = None,
+                 ack=False):
+        self._message = message
+        self._handler = handler
+        self._validator = validator
+        self._logger = None
+        self._phase = MessagePhase.WAITING
+        self._phase_update_time = 0
+        if not validator and ack:
+            self._validator = lambda m: isinstance(m, AckMessage)
+
+    def setlogger(self, logger: logging.Logger):
+        self._logger = logger
+
+    def validate(self, message: Message):
+        if not self._validator:
+            return True
+        return self._validator(message)
+
+    def call(self, *args, error_message: str = None) -> None:
+        if not self._handler:
+            return
+        try:
+            self._handler(*args)
+        except Exception as exc:
+            logger = self._logger or logging.getLogger(self.__class__.__name__)
+            logger.error(f'{error_message}, see exception below:')
+            logger.exception(exc)
+
+    @property
+    def phase(self) -> MessagePhase:
+        return self._phase
+
+    @phase.setter
+    def phase(self, phase: MessagePhase):
+        self._phase = phase
+        self._phase_update_time = 0 if phase == MessagePhase.WAITING else time.time()
+
+    @property
+    def phase_update_time(self) -> float:
+        return self._phase_update_time
+
+    @property
+    def message(self) -> Message:
+        return self._message
+
+    @property
+    def id(self) -> int:
+        return self._message.id
+
+    @property
+    def seq(self) -> int:
+        return self._message.seq
+
+    @seq.setter
+    def seq(self, seq: int):
+        self._message.seq = seq
+
+    def __repr__(self):
+        return f'<{__name__}.{self.__class__.__name__} message={self._message.__repr__()}>'
+
+
+# Connection stuff
+# Well, strictly speaking, as it's UDP, there's no connection, but who cares.
+# ---------------------------------------------------------------------------
+
+class IncomingMessageListener:
+    @abstractmethod
+    def incoming_message(self, message: Message) -> Optional[Message]:
+        pass
+
+
+class ConnectionStatus(Enum):
+    NOT_CONNECTED = auto()
+    CONNECTING = auto()
+    CONNECTED = auto()
+    RECONNECTING = auto()
+    DISCONNECTED = auto()
+
+
+class ConnectionStatusListener:
+    @abstractmethod
+    def connection_status_updated(self, status: ConnectionStatus):
+        pass
+
+
+class UDPConnection(threading.Thread, ConnectionStatusListener):
+    inseq: int
+    outseq: int
+    source_port: int
+    device_addr: str
+    device_port: int
+    device_token: bytes
+    device_pubkey: bytes
+    interrupted: bool
+    response_handlers: Dict[int, WrappedMessage]
+    outgoing_queue: List[WrappedMessage]
+    pubkey: Optional[bytes]
+    encinkey: Optional[bytes]
+    encoutkey: Optional[bytes]
+    inc_listeners: List[IncomingMessageListener]
+    conn_listeners: List[ConnectionStatusListener]
+    outgoing_time: float
+    outgoing_time_1st: float
+    incoming_time: float
+    status: ConnectionStatus
+    reconnect_tries: int
+    read_timeout: int
+
+    _addr_lock: threading.Lock
+    _iml_lock: threading.Lock
+    _csl_lock: threading.Lock
+    _st_lock: threading.Lock
+
+    def __init__(self,
+                 addr: Union[IPv4Address, IPv6Address],
+                 port: int,
+                 device_pubkey: bytes,
+                 device_token: bytes,
+                 read_timeout: int = 1):
+        super().__init__()
+        self._logger = logging.getLogger(f'{__name__}.{self.__class__.__name__} <{hex(id(self))}>')
+        self.setName(self.__class__.__name__)
+
+        self.inseq = 0
+        self.outseq = 0
+        self.source_port = random.randint(1024, 65535)
+        self.device_addr = str(addr)
+        self.device_port = port
+        self.device_token = device_token
+        self.device_pubkey = device_pubkey
+        self.outgoing_queue = []
+        self.response_handlers = {}
+        self.interrupted = False
+        self.outgoing_time = 0
+        self.outgoing_time_1st = 0
+        self.incoming_time = 0
+        self.inc_listeners = []
+        self.conn_listeners = [self]
+        self.status = ConnectionStatus.NOT_CONNECTED
+        self.reconnect_tries = 0
+        self.read_timeout = read_timeout
+
+        self._iml_lock = threading.Lock()
+        self._csl_lock = threading.Lock()
+        self._addr_lock = threading.Lock()
+        self._st_lock = threading.Lock()
+
+        self.pubkey = None
+        self.encinkey = None
+        self.encoutkey = None
+
+    def connection_status_updated(self, status: ConnectionStatus):
+        # self._logger.info(f'connection_status_updated: status = {status}')
+        with self._st_lock:
+            # self._logger.debug(f'connection_status_updated: lock acquired')
+            self.status = status
+            if status == ConnectionStatus.RECONNECTING:
+                self.reconnect_tries += 1
+            if status in (ConnectionStatus.CONNECTED, ConnectionStatus.NOT_CONNECTED, ConnectionStatus.DISCONNECTED):
+                self.reconnect_tries = 0
+
+    def _cleanup(self):
+        # erase outgoing queue
+        for wm in self.outgoing_queue:
+            wm.call(False,
+                    error_message=f'_cleanup: exception while calling cb(False) on message {wm.message}')
+        self.outgoing_queue = []
+        self.response_handlers = {}
+
+        # reset timestamps
+        self.incoming_time = 0
+        self.outgoing_time = 0
+        self.outgoing_time_1st = 0
+
+        self._logger.debug('_cleanup: done')
+
+    def set_address(self, addr: Union[IPv4Address, IPv6Address], port: int):
+        with self._addr_lock:
+            if self.device_addr != str(addr) or self.device_port != port:
+                self.device_addr = str(addr)
+                self.device_port = port
+                self._logger.info(f'updated device network address: {self.device_addr}:{self.device_port}')
+
+    def set_device_pubkey(self, pubkey: bytes):
+        if self.device_pubkey.hex() != pubkey.hex():
+            self._logger.info(f'device pubkey has changed (old={self.device_pubkey.hex()}, new={pubkey.hex()})')
+            self.device_pubkey = pubkey
+            self._notify_cs(ConnectionStatus.RECONNECTING)
+
+    def get_address(self) -> Tuple[str, int]:
+        with self._addr_lock:
+            return self.device_addr, self.device_port
+
+    def add_incoming_message_listener(self, listener: IncomingMessageListener):
+        with self._iml_lock:
+            if listener not in self.inc_listeners:
+                self.inc_listeners.append(listener)
+
+    def add_connection_status_listener(self, listener: ConnectionStatusListener):
+        with self._csl_lock:
+            if listener not in self.conn_listeners:
+                self.conn_listeners.append(listener)
+
+    def _notify_cs(self, status: ConnectionStatus):
+        # self._logger.debug(f'_notify_cs: status={status}')
+        with self._csl_lock:
+            for obj in self.conn_listeners:
+                # self._logger.debug(f'_notify_cs: notifying {obj}')
+                obj.connection_status_updated(status)
+
+    def _prepare_keys(self):
+        # generate key pair
+        privkey = X25519PrivateKey.generate()
+
+        self.pubkey = bytes(reversed(privkey.public_key().public_bytes(encoding=srlz.Encoding.Raw,
+                                                                       format=srlz.PublicFormat.Raw)))
+
+        # generate shared key
+        device_pubkey = X25519PublicKey.from_public_bytes(
+            bytes(reversed(self.device_pubkey))
+        )
+        shared_key = bytes(reversed(
+            privkey.exchange(device_pubkey)
+        ))
+
+        # in/out encryption keys
+        digest = hashes.Hash(hashes.SHA256())
+        digest.update(shared_key)
+
+        shared_sha256 = digest.finalize()
+
+        self.encinkey = shared_sha256[:16]
+        self.encoutkey = shared_sha256[16:]
+
+        self._logger.info('encryption keys have been created')
+
+    def _handshake_callback(self, r: MessageResponse):
+        # if got error for our HandshakeMessage, reset everything and try again
+        if r is False:
+            # self._logger.debug('_handshake_callback: set status=RECONNETING')
+            self._notify_cs(ConnectionStatus.RECONNECTING)
+        else:
+            # self._logger.debug('_handshake_callback: set status=CONNECTED')
+            self._notify_cs(ConnectionStatus.CONNECTED)
+
+    def run(self):
+        self._logger.info('starting server loop')
+
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        sock.bind(('0.0.0.0', self.source_port))
+        sock.settimeout(self.read_timeout)
+
+        while not self.interrupted:
+            with self._st_lock:
+                status = self.status
+
+            if status in (ConnectionStatus.DISCONNECTED, ConnectionStatus.RECONNECTING):
+                self._cleanup()
+                if status == ConnectionStatus.DISCONNECTED:
+                    break
+
+            # no activity for some time means connection is broken
+            fail = False
+            fail_path = 0
+            if self.incoming_time > 0 and time.time() - self.incoming_time >= DISCONNECT_TIMEOUT:
+                fail = True
+                fail_path = 1
+            elif self.outgoing_time_1st > 0 and self.incoming_time == 0 and time.time() - self.outgoing_time_1st >= DISCONNECT_TIMEOUT:
+                fail = True
+                fail_path = 2
+
+            if fail:
+                self._logger.debug(f'run: setting status=RECONNECTING because of long inactivity, fail_path={fail_path}')
+                self._notify_cs(ConnectionStatus.RECONNECTING)
+
+            # establishing a connection
+            if status in (ConnectionStatus.RECONNECTING, ConnectionStatus.NOT_CONNECTED):
+                if status == ConnectionStatus.RECONNECTING and self.reconnect_tries >= 3:
+                    self._notify_cs(ConnectionStatus.DISCONNECTED)
+                    continue
+
+                self._reset_outseq()
+                self._prepare_keys()
+
+                # shake the imaginary kettle's hand
+                wrapped = WrappedMessage(HandshakeMessage(),
+                                         handler=self._handshake_callback,
+                                         validator=lambda m: isinstance(m, (AckMessage, HandshakeResponseMessage)))
+                self.enqueue_message(wrapped, prepend=True)
+                self._notify_cs(ConnectionStatus.CONNECTING)
+
+            # pick next (wrapped) message to send
+            wm = self._get_next_message()  # wm means "wrapped message"
+            if wm:
+                one_shot = isinstance(wm.message, (AckMessage, NakMessage))
+
+                if not isinstance(wm.message, (AckMessage, NakMessage)):
+                    old_seq = wm.seq
+                    wm.seq = self.outseq
+                    self._set_response_handler(wm, old_seq=old_seq)
+                elif wm.seq is None:
+                    # ack/nak is a response to some incoming message (and it must have the same seqno that incoming
+                    # message had)
+                    raise RuntimeError(f'run: seq must be set for {wm.__class__.__name__}')
+
+                self._logger.debug(f'run: sending message: {wm.message}, one_shot={one_shot}, phase={wm.phase}')
+                encrypted = False
+                try:
+                    wm.message.encrypt(outkey=self.encoutkey, inkey=self.encinkey,
+                                       token=self.device_token, pubkey=self.pubkey)
+                    encrypted = True
+                except ValueError as exc:
+                    # handle "ValueError: Invalid padding bytes."
+                    self._logger.error('run: failed to encrypt the message.')
+                    self._logger.exception(exc)
+
+                if encrypted:
+                    buf = wm.message.frame.pack()
+                    # self._logger.debug(f'run: raw data to be sent: {buf.hex()}')
+
+                    # sending the first time
+                    if wm.phase == MessagePhase.WAITING:
+                        sock.sendto(buf, self.get_address())
+                    # resending
+                    elif wm.phase == MessagePhase.SENT:
+                        left = RESEND_ATTEMPTS
+                        while left > 0:
+                            sock.sendto(buf, self.get_address())
+                            left -= 1
+                            if left > 0:
+                                time.sleep(0.05)
+
+                    if one_shot or wm.phase == MessagePhase.SENT:
+                        wm.phase = MessagePhase.DONE
+                    else:
+                        wm.phase = MessagePhase.SENT
+
+                    now = time.time()
+                    self.outgoing_time = now
+                    if not self.outgoing_time_1st:
+                        self.outgoing_time_1st = now
+
+            # receiving data
+            try:
+                data = sock.recv(4096)
+                self._handle_incoming(data)
+            except (TimeoutError, socket.timeout):
+                pass
+
+        self._logger.info('bye...')
+
+    def _get_next_message(self) -> Optional[WrappedMessage]:
+        message = None
+        lpfx = '_get_next_message:'
+        remove_list = []
+        for wm in self.outgoing_queue:
+            if wm.phase == MessagePhase.DONE:
+                if isinstance(wm.message, (AckMessage, NakMessage, PingMessage)) or time.time() - wm.phase_update_time >= MESSAGE_QUEUE_REMOVE_DELAY:
+                    remove_list.append(wm)
+                continue
+            message = wm
+            break
+
+        for wm in remove_list:
+            self._logger.debug(f'{lpfx} rm path: removing id={wm.id} seq={wm.seq}')
+
+            # clear message handler
+            if wm.seq in self.response_handlers:
+                self.response_handlers[wm.seq].call(
+                    False, error_message=f'{lpfx} rm path: error while calling callback for seq={wm.seq}')
+                del self.response_handlers[wm.seq]
+
+            # remove from queue
+            try:
+                self.outgoing_queue.remove(wm)
+            except ValueError as exc:
+                self._logger.error(f'{lpfx} rm path: removing from outgoing_queue raised an exception: {str(exc)}')
+
+        # ping pong
+        if not message and self.outgoing_time_1st != 0 and self.status == ConnectionStatus.CONNECTED:
+            now = time.time()
+            out_delta = now - self.outgoing_time
+            in_delta = now - self.incoming_time
+            if max(out_delta, in_delta) > PING_FREQUENCY:
+                self._logger.debug(f'{lpfx} no activity: in for {in_delta:.2f}s, out for {out_delta:.2f}s, time to ping the damn thing')
+                message = WrappedMessage(PingMessage(), ack=True)
+                # add it to outgoing_queue in order to be aggressively resent in future (if needed)
+                self.outgoing_queue.insert(0, message)
+
+        return message
+
+    def _handle_incoming(self, buf: bytes):
+        try:
+            incoming_message = Message.from_encrypted(buf, inkey=self.encinkey, outkey=self.encoutkey)
+        except ValueError as exc:
+            # handle "ValueError: Invalid padding bytes."
+            self._logger.error('_handle_incoming: failed to decrypt incoming frame:')
+            self._logger.exception(exc)
+            return
+
+        self.incoming_time = time.time()
+        seq = incoming_message.seq
+
+        lpfx = f'handle_incoming({incoming_message.id}):'
+        self._logger.debug(f'{lpfx} received: {incoming_message}')
+
+        if isinstance(incoming_message, (AckMessage, NakMessage)):
+            seq_max = self.outseq
+            seq_name = 'outseq'
+        else:
+            seq_max = self.inseq
+            seq_name = 'inseq'
+            self.inseq = seq
+
+        if seq < seq_max < 0xfd:
+            self._logger.debug(f'{lpfx} dropping: seq={seq}, {seq_name}={seq_max}')
+            return
+
+        if seq not in self.response_handlers:
+            self._handle_incoming_cmd(incoming_message)
+            return
+
+        callback_value = None  # None means don't call a callback
+        handler = self.response_handlers[seq]
+
+        if handler.validate(incoming_message):
+            self._logger.debug(f'{lpfx} response OK')
+            handler.phase = MessagePhase.DONE
+            callback_value = incoming_message
+            self._incr_outseq()
+        else:
+            self._logger.warning(f'{lpfx} response is INVALID')
+
+            # It seems that we've received an incoming CmdMessage or PingMessage with the same seqno that our outgoing
+            # message had. Bad, but what can I say, this is quick-and-dirty made UDP based protocol and this sort of
+            # shit just happens.
+
+            # (To be fair, maybe my implementation is not perfect either. But hey, what did you expect from a
+            # reverse-engineered re-implementation of custom UDP-based protocol that some noname vendor uses for their
+            # cheap IoT devices? I think _that_ is _the_ definition of shit. At least my implementation is FOSS, which
+            # is more than you'll ever be able to say about them.)
+
+            # All this crapload of code below might not be needed at all, 'cause the protocol uses separate frame seq
+            # numbers for IN and OUT frames and this situation is not highly likely, as Theresa May could argue.
+            # After a handshake, a kettle sends us 10 or so CmdMessages, and then either we continuously ping it every
+            # 3 seconds, or kettle pings us. This in any case widens the gap between inseq and outseq.
+
+            # But! the seqno is only 1 byte in size and once it reaches 0xff, it circles back to zero. And that (plus,
+            # perhaps, some bad luck) gives a chance for a collision.
+
+            if handler.phase == MessagePhase.DONE or isinstance(handler.message, HandshakeMessage):
+                # no more attempts left, returning error back to user
+                # as to handshake, it cannot fail.
+                callback_value = False
+
+            # else:
+            #     # try resending the message
+            #     handler.phase_reset()
+            #     max_seq = self.outseq
+            #     wait_remap = {}
+            #     for m in self.outgoing_queue:
+            #         if m.seq in self.waiting_for_response:
+            #             wait_remap[m.seq] = (m.seq+1) % 256
+            #         m.set_seq((m.seq+1) % 256)
+            #         if m.seq > max_seq:
+            #             max_seq = m.seq
+            #     if max_seq > self.outseq:
+            #         self.outseq = max_seq % 256
+            #     if wait_remap:
+            #         waiting_new = {}
+            #         for old_seq, new_seq in wait_remap.items():
+            #             waiting_new[new_seq] = self.waiting_for_response[old_seq]
+            #         self.waiting_for_response = waiting_new
+
+            if isinstance(incoming_message, (PingMessage, CmdIncomingMessage)):
+                # handle incoming message as usual, as we need to ack/nak it anyway
+                self._handle_incoming_cmd(incoming_message)
+
+        if callback_value is not None:
+            handler.call(callback_value,
+                         error_message=f'{lpfx} error while calling callback for msg id={handler.message.id} seq={seq}')
+            del self.response_handlers[seq]
+
+    def _handle_incoming_cmd(self, incoming_message: Message):
+        if isinstance(incoming_message, (AckMessage, NakMessage)):
+            self._logger.debug(f'_handle_incoming_cmd({incoming_message.id}, seq={incoming_message.seq}): it\'s {incoming_message.__class__.__name__}, ignoring')
+            return
+
+        replied = False
+        with self._iml_lock:
+            for f in self.inc_listeners:
+                retval = safe_callback_call(f.incoming_message, incoming_message,
+                                            logger=self._logger,
+                                            error_message=f'_handle_incoming_cmd({incoming_message.id}, seq={incoming_message.seq}): error while calling message listener')
+                if isinstance(retval, Message):
+                    if isinstance(retval, (AckMessage, NakMessage)):
+                        retval.seq = incoming_message.seq
+                        self.enqueue_message(WrappedMessage(retval), prepend=True)
+                        replied = True
+                        break
+                    else:
+                        raise RuntimeError('are you sure your response is correct? only ack/nak are allowed')
+
+        if not replied:
+            self.enqueue_message(WrappedMessage(AckMessage(incoming_message.seq)), prepend=True)
+
+    def enqueue_message(self, wrapped: WrappedMessage, prepend=False):
+        self._logger.debug(f'enqueue_message: {wrapped.message}')
+        if not prepend:
+            self.outgoing_queue.append(wrapped)
+        else:
+            self.outgoing_queue.insert(0, wrapped)
+
+    def _set_response_handler(self, wm: WrappedMessage, old_seq=None):
+        if old_seq in self.response_handlers:
+            del self.response_handlers[old_seq]
+
+        seq = wm.seq
+        assert seq is not None, 'seq is not set'
+
+        if seq in self.response_handlers:
+            self._logger.debug(f'_set_response_handler(seq={seq}): handler is already set, cancelling it')
+            self.response_handlers[seq].call(False,
+                                             error_message=f'_set_response_handler({seq}): error while calling old callback')
+        self.response_handlers[seq] = wm
+
+    def _incr_outseq(self) -> None:
+        self.outseq = (self.outseq + 1) % 256
+
+    def _reset_outseq(self):
+        self.outseq = 0
+        self._logger.debug(f'_reset_outseq: set 0')
+
+
+MessageResponse = Union[Message, bool]