Adafruit_BME280.h

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#ifndef __BME280_H__
#define __BME280_H__

#include "Arduino.h"

#include <Adafruit_I2CDevice.h>
#include <Adafruit_SPIDevice.h>
#include <Adafruit_Sensor.h>

#define BME280_ADDRESS (0x77)           // Primary I2C Address

#define BME280_ADDRESS_ALTERNATE (0x76) // Alternate Address

enum {
  BME280_REGISTER_DIG_T1 = 0x88,
  BME280_REGISTER_DIG_T2 = 0x8A,
  BME280_REGISTER_DIG_T3 = 0x8C,

  BME280_REGISTER_DIG_P1 = 0x8E,
  BME280_REGISTER_DIG_P2 = 0x90,
  BME280_REGISTER_DIG_P3 = 0x92,
  BME280_REGISTER_DIG_P4 = 0x94,
  BME280_REGISTER_DIG_P5 = 0x96,
  BME280_REGISTER_DIG_P6 = 0x98,
  BME280_REGISTER_DIG_P7 = 0x9A,
  BME280_REGISTER_DIG_P8 = 0x9C,
  BME280_REGISTER_DIG_P9 = 0x9E,

  BME280_REGISTER_DIG_H1 = 0xA1,
  BME280_REGISTER_DIG_H2 = 0xE1,
  BME280_REGISTER_DIG_H3 = 0xE3,
  BME280_REGISTER_DIG_H4 = 0xE4,
  BME280_REGISTER_DIG_H5 = 0xE5,
  BME280_REGISTER_DIG_H6 = 0xE7,

  BME280_REGISTER_CHIPID = 0xD0,
  BME280_REGISTER_VERSION = 0xD1,
  BME280_REGISTER_SOFTRESET = 0xE0,

  BME280_REGISTER_CAL26 = 0xE1, // R calibration stored in 0xE1-0xF0

  BME280_REGISTER_CONTROLHUMID = 0xF2,
  BME280_REGISTER_STATUS = 0XF3,
  BME280_REGISTER_CONTROL = 0xF4,
  BME280_REGISTER_CONFIG = 0xF5,
  BME280_REGISTER_PRESSUREDATA = 0xF7,
  BME280_REGISTER_TEMPDATA = 0xFA,
  BME280_REGISTER_HUMIDDATA = 0xFD
};

/**************************************************************************/
/**************************************************************************/
typedef struct {
  uint16_t dig_T1; 
  int16_t dig_T2;  
  int16_t dig_T3;  

  uint16_t dig_P1; 
  int16_t dig_P2;  
  int16_t dig_P3;  
  int16_t dig_P4;  
  int16_t dig_P5;  
  int16_t dig_P6;  
  int16_t dig_P7;  
  int16_t dig_P8;  
  int16_t dig_P9;  

  uint8_t dig_H1; 
  int16_t dig_H2; 
  uint8_t dig_H3; 
  int16_t dig_H4; 
  int16_t dig_H5; 
  int8_t dig_H6;  
} bme280_calib_data;
/*=========================================================================*/

class Adafruit_BME280;

class Adafruit_BME280_Temp : public Adafruit_Sensor {
public:
  Adafruit_BME280_Temp(Adafruit_BME280 *parent) { _theBME280 = parent; }
  bool getEvent(sensors_event_t *);
  void getSensor(sensor_t *);

private:
  int _sensorID = 280;
  Adafruit_BME280 *_theBME280 = NULL;
};

class Adafruit_BME280_Pressure : public Adafruit_Sensor {
public:
  Adafruit_BME280_Pressure(Adafruit_BME280 *parent) { _theBME280 = parent; }
  bool getEvent(sensors_event_t *);
  void getSensor(sensor_t *);

private:
  int _sensorID = 280;
  Adafruit_BME280 *_theBME280 = NULL;
};

class Adafruit_BME280_Humidity : public Adafruit_Sensor {
public:
  Adafruit_BME280_Humidity(Adafruit_BME280 *parent) { _theBME280 = parent; }
  bool getEvent(sensors_event_t *);
  void getSensor(sensor_t *);

private:
  int _sensorID = 280;
  Adafruit_BME280 *_theBME280 = NULL;
};

/**************************************************************************/
/**************************************************************************/
class Adafruit_BME280 {
public:
  /**************************************************************************/
  /**************************************************************************/
  enum sensor_sampling {
    SAMPLING_NONE = 0b000,
    SAMPLING_X1 = 0b001,
    SAMPLING_X2 = 0b010,
    SAMPLING_X4 = 0b011,
    SAMPLING_X8 = 0b100,
    SAMPLING_X16 = 0b101
  };

  /**************************************************************************/
  /**************************************************************************/
  enum sensor_mode {
    MODE_SLEEP = 0b00,
    MODE_FORCED = 0b01,
    MODE_NORMAL = 0b11
  };

  /**************************************************************************/
  /**************************************************************************/
  enum sensor_filter {
    FILTER_OFF = 0b000,
    FILTER_X2 = 0b001,
    FILTER_X4 = 0b010,
    FILTER_X8 = 0b011,
    FILTER_X16 = 0b100
  };

  /**************************************************************************/
  /**************************************************************************/
  enum standby_duration {
    STANDBY_MS_0_5 = 0b000,
    STANDBY_MS_10 = 0b110,
    STANDBY_MS_20 = 0b111,
    STANDBY_MS_62_5 = 0b001,
    STANDBY_MS_125 = 0b010,
    STANDBY_MS_250 = 0b011,
    STANDBY_MS_500 = 0b100,
    STANDBY_MS_1000 = 0b101
  };

  // constructors
  Adafruit_BME280();
  Adafruit_BME280(int8_t cspin, SPIClass *theSPI = &SPI);
  Adafruit_BME280(int8_t cspin, int8_t mosipin, int8_t misopin, int8_t sckpin);
  ~Adafruit_BME280(void);
  bool begin(uint8_t addr = BME280_ADDRESS, TwoWire *theWire = &Wire);
  bool init();

  void setSampling(sensor_mode mode = MODE_NORMAL,
                   sensor_sampling tempSampling = SAMPLING_X16,
                   sensor_sampling pressSampling = SAMPLING_X16,
                   sensor_sampling humSampling = SAMPLING_X16,
                   sensor_filter filter = FILTER_OFF,
                   standby_duration duration = STANDBY_MS_0_5);

  bool takeForcedMeasurement(void);
  float readTemperature(void);
  float readPressure(void);
  float readHumidity(void);

  float readAltitude(float seaLevel);
  float seaLevelForAltitude(float altitude, float pressure);
  uint32_t sensorID(void);

  float getTemperatureCompensation(void);
  void setTemperatureCompensation(float);

  Adafruit_Sensor *getTemperatureSensor(void);
  Adafruit_Sensor *getPressureSensor(void);
  Adafruit_Sensor *getHumiditySensor(void);

protected:
  Adafruit_I2CDevice *i2c_dev = NULL; 
  Adafruit_SPIDevice *spi_dev = NULL; 

  Adafruit_BME280_Temp *temp_sensor = NULL;

  Adafruit_BME280_Pressure *pressure_sensor = NULL;

  Adafruit_BME280_Humidity *humidity_sensor = NULL;

  void readCoefficients(void);
  bool isReadingCalibration(void);

  void write8(byte reg, byte value);
  uint8_t read8(byte reg);
  uint16_t read16(byte reg);
  uint32_t read24(byte reg);
  int16_t readS16(byte reg);
  uint16_t read16_LE(byte reg); // little endian
  int16_t readS16_LE(byte reg); // little endian

  uint8_t _i2caddr;  
  int32_t _sensorID; 
  int32_t t_fine; 

  int32_t t_fine_adjust = 0; 

  bme280_calib_data _bme280_calib; 

  /**************************************************************************/
  /**************************************************************************/
  struct config {
    // inactive duration (standby time) in normal mode
    // 000 = 0.5 ms
    // 001 = 62.5 ms
    // 010 = 125 ms
    // 011 = 250 ms
    // 100 = 500 ms
    // 101 = 1000 ms
    // 110 = 10 ms
    // 111 = 20 ms
    unsigned int t_sb : 3; 

    // filter settings
    // 000 = filter off
    // 001 = 2x filter
    // 010 = 4x filter
    // 011 = 8x filter
    // 100 and above = 16x filter
    unsigned int filter : 3; 

    // unused - don't set
    unsigned int none : 1;     
    unsigned int spi3w_en : 1; 

    unsigned int get() { return (t_sb << 5) | (filter << 2) | spi3w_en; }
  };
  config _configReg; 

  /**************************************************************************/
  /**************************************************************************/
  struct ctrl_meas {
    // temperature oversampling
    // 000 = skipped
    // 001 = x1
    // 010 = x2
    // 011 = x4
    // 100 = x8
    // 101 and above = x16
    unsigned int osrs_t : 3; 

    // pressure oversampling
    // 000 = skipped
    // 001 = x1
    // 010 = x2
    // 011 = x4
    // 100 = x8
    // 101 and above = x16
    unsigned int osrs_p : 3; 

    // device mode
    // 00       = sleep
    // 01 or 10 = forced
    // 11       = normal
    unsigned int mode : 2; 

    unsigned int get() { return (osrs_t << 5) | (osrs_p << 2) | mode; }
  };
  ctrl_meas _measReg; 

  /**************************************************************************/
  /**************************************************************************/
  struct ctrl_hum {
    unsigned int none : 5;

    // humidity oversampling
    // 000 = skipped
    // 001 = x1
    // 010 = x2
    // 011 = x4
    // 100 = x8
    // 101 and above = x16
    unsigned int osrs_h : 3; 

    unsigned int get() { return (osrs_h); }
  };
  ctrl_hum _humReg; 
};

#endif