BMP280.h

/*
	BMP280.h
	Bosch BMP280 pressure sensor library for the Arduino microcontroller.
	This library uses I2C connection.

	Uses floating-point equations from BMP280 datasheet.

	modified by mhafuzul islam

	version 1.01		 16/9/2014 initial version
	
	Our example code uses the "pizza-eating" license. You can do anything
	you like with this code. No really, anything. If you find it useful,
	buy me italian pizza someday.
*/

#ifndef BMP280_h
#define BMP280_h

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

// #define _debugSerial
// #define _debugTestData

class BMP280
{
	public:
		BMP280(); // base type

		char begin();
		char begin(int sdaPin, int sclPin);
			// call pressure.begin() to initialize BMP280 before use
			// returns 1 if success, 0 if failure (i2C connection problem.)
				
		short getOversampling(void);
		char  setOversampling(short oss);
		
		char startMeasurment(void);
			// command BMP280 to start a pressure measurement
			// oversampling: 0 - 3 for oversampling value
			// returns (number of ms to wait) for success, 0 for fail
		
		char calcTemperature(double &T, double &uT);
			// calculation the true temperature from the given uncalibrated Temperature 
			
		char calcPressure(double &P, double uP);
			//calculation for measuring pressure.
			
		double sealevel(double P, double A);
			// convert absolute pressure to sea-level pressure 
			// P: absolute pressure (mbar)
			// A: current altitude (meters)
			// returns sealevel pressure in mbar

		double altitude(double P, double P0);
			// convert absolute pressure to altitude (given baseline pressure; sea-level, runway, etc.)
			// P: absolute pressure (mbar)
			// P0: fixed baseline pressure (mbar)
			// returns signed altitude in meters

		char getError(void);
			// If any library command fails, you can retrieve an extended
			// error code using this command. Errors are from the wire library: 
			// 0 = Success
			// 1 = Data too long to fit in transmit buffer
			// 2 = Received NACK on transmit of address
			// 3 = Received NACK on transmit of data
			// 4 = Other error
			
		char getTemperatureAndPressure(double& T,double& P);

	private:
	
		char readCalibration();
			// Retrieve calibration data from device:
			// The BMP280 includes factory calibration data stored on the device.
			// Each device has different numbers, these must be retrieved and
			// used in the calculations when taking measurements.

		char readInt(char address, double &value);
			// read an signed int (16 bits) from a BMP280 register
			// address: BMP280 register address
			// value: external signed int for returned value (16 bits)
			// returns 1 for success, 0 for fail, with result in value

		char readUInt(char address, double &value);
			// read an unsigned int (16 bits) from a BMP280 register
			// address: BMP280 register address
			// value: external unsigned int for returned value (16 bits)
			// returns 1 for success, 0 for fail, with result in value

		char readBytes(unsigned char *values, char length);
			// read a number of bytes from a BMP280 register
			// values: array of char with register address in first location [0]
			// length: number of bytes to read back
			// returns 1 for success, 0 for fail, with read bytes in values[] array
			
		char writeBytes(unsigned char *values, char length);
			// write a number of bytes to a BMP280 register (and consecutive subsequent registers)
			// values: array of char with register address in first location [0]
			// length: number of bytes to write
			// returns 1 for success, 0 for fail
		
		char getUnPT(double &uP, double &uT);	
			//get uncalibrated UP and UT value.
	
				
		//int dig_T2 , dig_T3 , dig_T4 , dig_P2 , dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9; 
		//unsigned int dig_P1 , dig_T1 ;
		double dig_T1, dig_T2 , dig_T3 , dig_T4 , dig_P1, dig_P2 , dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9; 
		short oversampling, oversampling_t;
		double t_fine;
		char error;
};

#define BMP280_ADDR 0x76 // 7-bit address

#define	BMP280_REG_CONTROL 0xF4
#define	BMP280_REG_RESULT_PRESSURE 0xF7			// 0xF7(msb) , 0xF8(lsb) , 0xF9(xlsb) : stores the pressure data.
#define BMP280_REG_RESULT_TEMPRERATURE 0xFA		// 0xFA(msb) , 0xFB(lsb) , 0xFC(xlsb) : stores the temperature data.

#define	BMP280_COMMAND_TEMPERATURE 0x2E
#define	BMP280_COMMAND_PRESSURE0 0x25  			 
#define	BMP280_COMMAND_PRESSURE1 0x29  			
#define	BMP280_COMMAND_PRESSURE2 0x2D    
#define	BMP280_COMMAND_PRESSURE3 0x31    
#define	BMP280_COMMAND_PRESSURE4 0x5D    

#endif