/*
 *  spreadspace avr utils
 *
 *
 *  Copyright (C) 2016 Bernhard Tittelbach <bernhard@tittelbach.org>
 *  Thanks to Adafruit for writing a great example. Go buy their stuff!
 *
 *  This file is part of spreadspace avr utils.
 *
 *  spreadspace avr utils is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  spreadspace avr utils is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef SPREADAVR_bmp280_h_INCLUDED
#define SPREADAVR_bmp280_h_INCLUDED

#ifdef __cplusplus
extern "C" {
#endif

#define BMP280_AVERAGE_SEA_LEVEL_PRESSURE 1013.25
#define BMP280_LUFA_SPIO_OPTIONS SPI_SPEED_FCPU_DIV_32  | SPI_MODE_MASTER | SPI_ORDER_MSB_FIRST | SPI_SCK_LEAD_RISING | SPI_SAMPLE_LEADING

/*=========================================================================
REGISTERS
-----------------------------------------------------------------------*/
enum
{
  BMP280_REGISTER_DIG_T1              = 0x88,
  BMP280_REGISTER_DIG_T2              = 0x8A,
  BMP280_REGISTER_DIG_T3              = 0x8C,

  BMP280_REGISTER_DIG_P1              = 0x8E,
  BMP280_REGISTER_DIG_P2              = 0x90,
  BMP280_REGISTER_DIG_P3              = 0x92,
  BMP280_REGISTER_DIG_P4              = 0x94,
  BMP280_REGISTER_DIG_P5              = 0x96,
  BMP280_REGISTER_DIG_P6              = 0x98,
  BMP280_REGISTER_DIG_P7              = 0x9A,
  BMP280_REGISTER_DIG_P8              = 0x9C,
  BMP280_REGISTER_DIG_P9              = 0x9E,

  BMP280_REGISTER_CHIPID             = 0xD0,
  BMP280_REGISTER_VERSION            = 0xD1,
  BMP280_REGISTER_SOFTRESET          = 0xE0,

  BMP280_REGISTER_CAL26              = 0xE1,  // R calibration stored in 0xE1-0xF0

  BMP280_REGISTER_CONTROL            = 0xF4,
  BMP280_REGISTER_CONFIG             = 0xF5,
  BMP280_REGISTER_PRESSUREDATA       = 0xF7,
  BMP280_REGISTER_TEMPDATA           = 0xFA,
};

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


/*=========================================================================
CALIBRATION DATA
-----------------------------------------------------------------------*/
typedef struct
{
  volatile uint8_t *cs_port;
  uint8_t  cs_pin;

  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;
} bmp280_sensor;
/*=========================================================================*/

typedef struct
{
  float temperature;
  float pressure;
} bmp280_result;


//make sure to configure the cs_pin as OUTPUT beforehand
//make sure to configure SPI beforehand
uint8_t bmp280_init(bmp280_sensor *sensor, volatile uint8_t *cs_port, uint8_t cs_pin);
//check if we deal with am bmp280 chip
uint8_t bmp280_check_chipid(bmp280_sensor *sensor);
//returns temperature in degress celsius
float bmp280_readTemp(bmp280_sensor *sensor);
//returns ambient pressure in pascal
float bmp280_readPressure(bmp280_sensor *sensor);
//read Temperature and Pressure in one fell swoop
bmp280_result bmp280_readTempAndPressure(bmp280_sensor *sensor);
//calculate altitude from measured pressure and given sealevel-pressure
float bmp280_calcAltitude(float pressure, float sealevelp);
//readPressure and calculate altitude
float bmp280_readAltitude(bmp280_sensor *sensor, float sealevelp);

#ifdef __cplusplus
}
#endif

#endif