2 files changed, 125 insertions, 0 deletions
diff --git a/platformio/common/libs/temphum/homekit/temphum.cpp b/platformio/common/libs/temphum/homekit/temphum.cpp
new file mode 100644
index 0000000..ac4d371
--- /dev/null
+++ b/platformio/common/libs/temphum/homekit/temphum.cpp
@@ -0,0 +1,87 @@
+#ifndef CONFIG_TARGET_ESP01
+#include <Arduino.h>
+#endif
+#include <homekit/logging.h>
+#include "temphum.h"
+
+namespace homekit::temphum {
+
+void Sensor::setup() const {
+#ifndef CONFIG_TARGET_ESP01
+    pinMode(CONFIG_SDA_GPIO, OUTPUT);
+    pinMode(CONFIG_SCL_GPIO, OUTPUT);
+
+    Wire.begin(CONFIG_SDA_GPIO, CONFIG_SCL_GPIO);
+#else
+    Wire.begin();
+#endif
+}
+
+void Sensor::writeCommand(int reg) const {
+    Wire.beginTransmission(dev_addr);
+    Wire.write(reg);
+    Wire.endTransmission();
+    delay(500); // wait for the measurement to be ready
+}
+
+SensorData Si7021::read() {
+    uint8_t error = 0;
+    writeCommand(0xf3); // command to measure temperature
+    Wire.requestFrom(dev_addr, 2);
+    if (Wire.available() < 2) {
+        PRINTLN("Si7021: 0xf3: could not read 2 bytes");
+    }
+    uint16_t temp_raw = Wire.read() << 8 | Wire.read();
+    double temperature = ((175.72 * temp_raw) / 65536.0) - 46.85;
+
+    writeCommand(0xf5); // command to measure humidity
+    Wire.requestFrom(dev_addr, 2);
+    if (Wire.available() < 2) {
+        PRINTLN("Si7021: 0xf5: could not read 2 bytes");
+    }
+    uint16_t hum_raw = Wire.read() << 8 | Wire.read();
+    double humidity = ((125.0 * hum_raw) / 65536.0) - 6.0;
+
+    return {
+        .error = error,
+        .temp = temperature,
+        .rh = humidity
+    };
+}
+
+SensorData DHT12::read() {
+    SensorData sd;
+    byte raw[5];
+    sd.error = 1;
+
+    writeCommand(0);
+    Wire.requestFrom(dev_addr, 5);
+
+    if (Wire.available() < 5) {
+        PRINTLN("DHT12: could not read 5 bytes");
+        goto end;
+    }
+
+    // Parse the received data
+    for (uint8_t i = 0; i < 5; i++)
+        raw[i] = Wire.read();
+
+    if (((raw[0] + raw[1] + raw[2] + raw[3]) & 0xff) != raw[4]) {
+        PRINTLN("DHT12: checksum error");
+        goto end;
+    }
+
+    // Calculate temperature and humidity values
+    sd.temp = raw[2] + (raw[3] & 0x7f) * 0.1;
+    if (raw[3] & 0x80)
+        sd.temp *= -1;
+
+    sd.rh = raw[0] + raw[1] * 0.1;
+
+    sd.error = 0;
+
+end:
+    return sd;
+}
+
+}
+\ No newline at end of file
diff --git a/platformio/common/libs/temphum/homekit/temphum.h b/platformio/common/libs/temphum/homekit/temphum.h
new file mode 100644
index 0000000..1952ce0
--- /dev/null
+++ b/platformio/common/libs/temphum/homekit/temphum.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <Wire.h>
+
+namespace homekit::temphum {
+
+struct SensorData {
+    uint8_t error = 0;
+    double temp = 0; // celsius
+    double rh = 0; // relative humidity percentage
+};
+
+
+class Sensor {
+protected:
+    int dev_addr;
+public:
+    explicit Sensor(int dev) : dev_addr(dev) {}
+    void setup() const;
+    void writeCommand(int reg) const;
+    virtual SensorData read() = 0;
+};
+
+
+class Si7021 : public Sensor {
+public:
+    SensorData read() override;
+    Si7021() : Sensor(0x40) {}
+};
+
+
+class DHT12 : public Sensor {
+public:
+    SensorData read() override;
+    DHT12() : Sensor(0x5c) {}
+};
+
+}
+\ No newline at end of file