matter_sensors.tc

Matter environmental sensors — Temperature + Humidity + Pressure (pure TinyC).

Source on GitHub

// Matter environmental sensors — Temperature + Humidity + Pressure (pure TinyC).
//
// Declares three Matter sensor endpoints on the matter_c engine:
//   Endpoint 1: Temperature Sensor (0x0302) -> TemperatureMeasurement (0x0402)
//   Endpoint 2: Humidity Sensor    (0x0307) -> RelativeHumidityMeasurement (0x0405)
//   Endpoint 3: Pressure Sensor    (0x0305) -> PressureMeasurement (0x0403)
//
// Matter MeasuredValue units (Matter 1.4 spec):
//   Temperature : int16,  0.01 °C   (e.g. 2137 = 21.37 °C, -512 = -5.12 °C)
//   Humidity    : uint16, 0.01 %    (e.g. 5500 = 55.00 %RH)
//   Pressure    : int16,  1 hPa     (MeasuredValue = 10 x kPa; 1013 = 1013 hPa)
//
// Temperature & pressure are SIGNED (MTR_S16) so sub-zero readings show
// correctly. Humidity is unsigned (MTR_U16).
//
// Publishing uses matterSetFloat(ep, cluster, attr, value, scale): pass the
// real float reading and an integer scale, and it stores round(value*scale) in
// the Matter wire units. e.g. 21.37 °C with scale 100 -> 2137 (0.01 °C).
//
// Open pairing from the web /mt page (Bind), then add in Apple/Google/Alexa.
//
// NOTE: values below are SIMULATED so the example runs on any board. For a real
// BME280/SHT3x etc., replace the readings in EverySecond() with sensorGet(),
// e.g.  t = sensorGet("BME280#Temperature");   // already a float in °C

int ep_temp;     // temperature endpoint id
int ep_hum;      // humidity endpoint id
int ep_press;    // pressure endpoint id
int tick;        // seconds counter for the simulated waveform

// Push fresh readings into the Matter attributes. Controllers pick them up on
// their subscription's report interval (or when the accessory view is opened).
void EverySecond() {
    float t; float h; float p;
    tick = tick + 1;
    // Simulated float readings that drift so you can watch them change in Home.
    t = 11.0 + 20.0 * sin((float)tick / 60.0);    // ~ -9 .. +31 °C  (signed!)
    h = 55.0 + 15.0 * sin((float)tick / 45.0);    // ~40 .. 70 %RH
    p = 1013.0 + 12.0 * sin((float)tick / 90.0);  // ~1001 .. 1025 hPa
    matterSetFloat(ep_temp,  CLUSTER_TEMP,  0, t, 100);   // °C  -> 0.01 °C
    matterSetFloat(ep_hum,   CLUSTER_HUM,   0, h, 100);   // %   -> 0.01 %
    matterSetFloat(ep_press, CLUSTER_PRESS, 0, p, 1);     // hPa -> hPa
}

int main() {
    tick = 0;
    matterReset();                     // clean data model (root node only)

    // Endpoint 1 — Temperature Sensor
    ep_temp = matterAdd(MATTER_TEMP_SENSOR);
    matterName(ep_temp, "Temperature");              // accessory title in the controller
    matterCluster(ep_temp, CLUSTER_TEMP);
    matterAttr(ep_temp, CLUSTER_TEMP, 0, MTR_S16);   // MeasuredValue (int16, 0.01 °C)
    matterSet(ep_temp, CLUSTER_TEMP, 0, 2100);       // seed 21.00 °C

    // Endpoint 2 — Relative Humidity Sensor
    ep_hum = matterAdd(MATTER_HUM_SENSOR);
    matterName(ep_hum, "Humidity");                  // accessory title in the controller
    matterCluster(ep_hum, CLUSTER_HUM);
    matterAttr(ep_hum, CLUSTER_HUM, 0, MTR_U16);     // MeasuredValue (uint16, 0.01 %)
    matterSet(ep_hum, CLUSTER_HUM, 0, 5000);         // seed 50.00 %

    // Endpoint 3 — Pressure Sensor
    ep_press = matterAdd(MATTER_PRESS_SENSOR);
    matterName(ep_press, "Pressure");                // accessory title in the controller
    matterCluster(ep_press, CLUSTER_PRESS);
    matterAttr(ep_press, CLUSTER_PRESS, 0, MTR_S16); // MeasuredValue (int16, hPa)
    matterSet(ep_press, CLUSTER_PRESS, 0, 1013);     // seed 1013 hPa

    matterStart();                     // Matter on; press Bind on /mt to pair
    return 0;
}