WipperSnapper_I2C_Driver_SCD4X.h

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#ifndef WipperSnapper_I2C_Driver_SCD4X_H
#define WipperSnapper_I2C_Driver_SCD4X_H

#include "WipperSnapper_I2C_Driver.h"
#include <SensirionI2cScd4x.h>
#include <Wire.h>

/**************************************************************************/
/**************************************************************************/
class WipperSnapper_I2C_Driver_SCD4X : public WipperSnapper_I2C_Driver {

public:
  /*******************************************************************************/
  /*******************************************************************************/
  WipperSnapper_I2C_Driver_SCD4X(TwoWire *i2c, uint16_t sensorAddress)
      : WipperSnapper_I2C_Driver(i2c, sensorAddress) {
    _i2c = i2c;
    _sensorAddress = sensorAddress;
  }

  /*******************************************************************************/
  /*******************************************************************************/
  bool begin() {
    _scd = new SensirionI2cScd4x();
    _scd->begin(*_i2c, _sensorAddress);

    // stop previously started measurement
    if (_scd->stopPeriodicMeasurement() != 0) {
      return false;
    }

    // start measurements
    if (_scd->startPeriodicMeasurement() != 0) {
      return false;
    }

    return true;
  }

  /*******************************************************************************/
  /*******************************************************************************/
  bool HasBeenReadInLastSecond() {
    return _lastRead != 0 && millis() - _lastRead < ONE_SECOND_IN_MILLIS;
  }

  /*******************************************************************************/
  /*******************************************************************************/
  bool IsSensorReady() {
    bool isDataReady = false;
    for (int i = 0; i < 2; i++) {
      uint16_t error = _scd->getDataReadyStatus(isDataReady);
      if (error == 0 && isDataReady) {
        return true;
      }
      delay(100);
    }
    return false;
  }

  /*******************************************************************************/
  /*******************************************************************************/
  bool ReadSensorData() {
    // dont read sensor more than once per second
    if (HasBeenReadInLastSecond()) {
      return true;
    }

    if (!IsSensorReady()) {
      return false;
    }

    // Read SCD4x measurement
    uint16_t co2 = 0;
    float temperature = 0;
    float humidity = 0;
    int16_t error = _scd->readMeasurement(co2, temperature, humidity);
    if (error != 0 || co2 == 0) {
      return false;
    }
    _CO2.CO2 = co2;
    _temperature.temperature = temperature;
    _humidity.relative_humidity = humidity;
    _lastRead = millis();
    return true;
  }

  /*******************************************************************************/
  /*******************************************************************************/
  bool getEventAmbientTemp(sensors_event_t *tempEvent) {
    // read all sensor measurements
    if (!ReadSensorData()) {
      return false;
    }

    *tempEvent = _temperature;
    return true;
  }

  /*******************************************************************************/
  /*******************************************************************************/
  bool getEventRelativeHumidity(sensors_event_t *humidEvent) {
    // read all sensor measurements
    if (!ReadSensorData()) {
      return false;
    }

    *humidEvent = _humidity;
    return true;
  }

  /*******************************************************************************/
  /*******************************************************************************/
  bool getEventCO2(sensors_event_t *co2Event) {
    // read all sensor measurements
    if (!ReadSensorData()) {
      return false;
    }

    *co2Event = _CO2;
    return true;
  }

protected:
  SensirionI2cScd4x *_scd = nullptr;  
  sensors_event_t _temperature = {0}; 
  sensors_event_t _humidity = {0};    
  sensors_event_t _CO2 = {0};         
  ulong _lastRead = 0uL;              
};

#endif // WipperSnapper_I2C_Driver_SCD4X_H