/***************************************************************************
  This is a library for the BME280 humidity, temperature & pressure sensor

  Designed specifically to work with the Adafruit BME280 Breakout
  ----> http://www.adafruit.com/products/2650

  These sensors use I2C or SPI to communicate, 2 or 4 pins are required
  to interface.

  Adafruit invests time and resources providing this open source code,
  please support Adafruit andopen-source hardware by purchasing products
  from Adafruit!

  Written by Limor Fried & Kevin Townsend for Adafruit Industries.
  BSD license, all text above must be included in any redistribution


 ***************************************************************************/
#ifndef __BME280_H__
#define __BME280_H__

#if (ARDUINO >= 100)
 #include "Arduino.h"
#else
 #include "WProgram.h"
#endif

#include <Wire.h>

/*=========================================================================
    I2C ADDRESS/BITS
    -----------------------------------------------------------------------*/
    #define BME280_ADDRESS                (0x77)
/*=========================================================================*/

/*=========================================================================
    REGISTERS
    -----------------------------------------------------------------------*/
    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_CONTROL            = 0xF4,
      BME280_REGISTER_CONFIG             = 0xF5,
      BME280_REGISTER_PRESSUREDATA       = 0xF7,
      BME280_REGISTER_TEMPDATA           = 0xFA,
      BME280_REGISTER_HUMIDDATA          = 0xFD,
    };

/*=========================================================================*/

/*=========================================================================
    CALIBRATION DATA
    -----------------------------------------------------------------------*/
    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 BME280
{
  public:

    bool  begin(uint8_t addr = BME280_ADDRESS);
    float temperature(void);
    float pressure(void);
    float humidity(void);
    float altitude(float seaLevel);

  private:

    void readCoefficients(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;

    bme280_calib_data _bme280_calib;

};

extern BME280 bme280;

#endif