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author | Evgeny Zinoviev <me@ch1p.io> | 2023-06-10 23:02:34 +0300 |
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committer | Evgeny Zinoviev <me@ch1p.io> | 2023-06-10 23:02:34 +0300 |
commit | b0bf43e6a272d42a55158e657bd937cb82fc3d8d (patch) | |
tree | f1bc13253bc028abcaed9c88882f5aee384a269c /py_include/homekit/temphum/i2c.py | |
parent | f3b9d50496257d87757802dfb472b5ffae11962c (diff) |
move files, rename home package to homekit
Diffstat (limited to 'py_include/homekit/temphum/i2c.py')
-rw-r--r-- | py_include/homekit/temphum/i2c.py | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/py_include/homekit/temphum/i2c.py b/py_include/homekit/temphum/i2c.py new file mode 100644 index 0000000..7d8e2e3 --- /dev/null +++ b/py_include/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') |