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/****************************************************************************
* BMP085.h - BMP085/I2C (Digital Pressure Sensor) library for Arduino *
* Copyright 2010-2011 Filipe Vieira & various contributors *
* *
* This file is part of BMP085 Arduino library. *
* *
* This library is free software: you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as published *
* by the Free Software Foundation, either version 3 of the License, or *
* (at your option) any later version. *
* *
* This program 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 Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
****************************************************************************/
/****************************************************************************
* Tested on Arduino Mega with BMP085 Breakout *
* SDA -> pin 20 (no pull up resistors) *
* SCL -> pin 21 (no pull up resistors) *
* XCLR -> not connected *
* EOC -> not connected *
* GND -> pin GND *
* VCC -> pin 3.3V *
* NOTE: SCL and SDA needs pull-up resistors for each I2C bus. *
* 2.2kOhm..10kOhm, typ. 4.7kOhm *
*****************************************************************************/
#ifndef BMP085_h
#define BMP085_h
#include "WProgram.h"
#define BMP085_ADDR 0x77 //0x77 default I2C address
#define BUFFER_SIZE 3
#define AUTO_UPDATE_TEMPERATURE true //default is true
// when true, temperature is measured everytime pressure is measured (Auto).
// when false, user chooses when to measure temperature (just call calcTrueTemperature()).
// used for dynamic measurement to increase sample rate (see BMP085 modes below).
/* ---- Registers ---- */
#define CAL_AC1 0xAA // R Calibration data (16 bits)
#define CAL_AC2 0xAC // R Calibration data (16 bits)
#define CAL_AC3 0xAE // R Calibration data (16 bits)
#define CAL_AC4 0xB0 // R Calibration data (16 bits)
#define CAL_AC5 0xB2 // R Calibration data (16 bits)
#define CAL_AC6 0xB4 // R Calibration data (16 bits)
#define CAL_B1 0xB6 // R Calibration data (16 bits)
#define CAL_B2 0xB8 // R Calibration data (16 bits)
#define CAL_MB 0xBA // R Calibration data (16 bits)
#define CAL_MC 0xBC // R Calibration data (16 bits)
#define CAL_MD 0xBE // R Calibration data (16 bits)
#define CONTROL 0xF4 // W Control register
#define CONTROL_OUTPUT 0xF6 // R Output registers 0xF6=MSB, 0xF7=LSB, 0xF8=XLSB
// unused registers
#define SOFTRESET 0xE0
#define VERSION 0xD1 // ML_VERSION pos=0 len=4 msk=0F AL_VERSION pos=4 len=4 msk=f0
#define CHIPID 0xD0 // pos=0 mask=FF len=8
// BMP085_CHIP_ID=0x55
/************************************/
/* REGISTERS PARAMETERS */
/************************************/
// BMP085 Modes
#define MODE_ULTRA_LOW_POWER 0 //oversampling=0, internalsamples=1, maxconvtimepressure=4.5ms, avgcurrent=3uA, RMSnoise_hPA=0.06, RMSnoise_m=0.5
#define MODE_STANDARD 1 //oversampling=1, internalsamples=2, maxconvtimepressure=7.5ms, avgcurrent=5uA, RMSnoise_hPA=0.05, RMSnoise_m=0.4
#define MODE_HIGHRES 2 //oversampling=2, internalsamples=4, maxconvtimepressure=13.5ms, avgcurrent=7uA, RMSnoise_hPA=0.04, RMSnoise_m=0.3
#define MODE_ULTRA_HIGHRES 3 //oversampling=3, internalsamples=8, maxconvtimepressure=25.5ms, avgcurrent=12uA, RMSnoise_hPA=0.03, RMSnoise_m=0.25
// "Sampling rate can be increased to 128 samples per second (standard mode) for
// dynamic measurement.In this case it is sufficient to measure temperature only
// once per second and to use this value for all pressure measurements during period."
// (from BMP085 datasheet Rev1.2 page 10).
// To use dynamic measurement set AUTO_UPDATE_TEMPERATURE to false and
// call calcTrueTemperature() from your code.
// Control register
#define READ_TEMPERATURE 0x2E
#define READ_PRESSURE 0x34
//Other
#define MSLP 101325 // Mean Sea Level Pressure = 1013.25 hPA (1hPa = 100Pa = 1mbar)
class BMP085 {
public:
BMP085();
// BMP initialization
void init(); // sets current elevation above ground level to 0 meters
void init(byte _BMPMode, int32_t _initVal, bool _centimeters); // sets a reference datum
// if _centimeters=false _initVal is Pa
// Who Am I
byte getDevAddr();
// BMP mode
byte getMode();
void setMode(byte _BMPMode); // BMP085 mode
// initialization
void setLocalPressure(int32_t _Pa); // set known barometric pressure as reference Ex. QNH
void setLocalAbsAlt(int32_t _centimeters); // set known altitude as reference
void setAltOffset(int32_t _centimeters); // altitude offset
void sethPaOffset(int32_t _Pa); // pressure offset
void zeroCal(int32_t _Pa, int32_t _centimeters);// zero Calibrate output to a specific Pa/altitude
// BMP Sensors
void getPressure(int32_t *_Pa); // pressure in Pa + offset
void getAltitude(int32_t *_centimeters); // altitude in centimeters + offset
void getTemperature(int32_t *_Temperature); // temperature in Cº
void calcTrueTemperature(); // calc temperature data b5 (only needed if AUTO_UPDATE_TEMPERATURE is false)
void calcTruePressure(long *_TruePressure); // calc Pressure in Pa
// dummy stuff
void dumpCalData(); // debug only
void writemem(uint8_t _addr, uint8_t _val);
void readmem(uint8_t _addr, uint8_t _nbytes, uint8_t __buff[]);
private:
int ac1,ac2,ac3,b1,b2,mb,mc,md; // cal data
unsigned int ac4,ac5,ac6; // cal data
long b5, oldEMA; // temperature data
uint8_t _dev_address;
byte _buff[BUFFER_SIZE]; // buffer MSB LSB XLSB
int _oss; // OverSamplingSetting
int _pressure_waittime[4]; // Max. Conversion Time Pressure is ms for each mode
int32_t _cm_Offset, _Pa_Offset;
int32_t _param_datum, _param_centimeters;
void getCalData();
};
#endif