Arduino/DIY-Arduino-variometer
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
Files
982dcb7ff9d2d4437d84f79f80cc66ff8679477c
DIY-Arduino-variometer/libraries/Adafruit_BMP085_U/Adafruit_BMP085_U.cpp
sinseman 84f8be374b Update librairies
2014-08-31 11:02:51 +02:00

437 lines
13 KiB
C++
Raw Blame History

/***************************************************************************
This is a library for the BMP085 pressure sensor
Designed specifically to work with the Adafruit BMP085 or BMP180 Breakout
----> http://www.adafruit.com/products/391
----> http://www.adafruit.com/products/1603
These displays use I2C to communicate, 2 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 Kevin Townsend for Adafruit Industries.
BSD license, all text above must be included in any redistribution
***************************************************************************/
#if ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#ifdef __AVR_ATtiny85__
#include "TinyWireM.h"
#define Wire TinyWireM
#else
#include <Wire.h>
#endif
#include <math.h>
#include <limits.h>
#include "Adafruit_BMP085_U.h"
static bmp085_calib_data _bmp085_coeffs; // Last read accelerometer data will be available here
static uint8_t _bmp085Mode;
#define BMP085_USE_DATASHEET_VALS (0) /* Set to 1 for sanity check */
/***************************************************************************
PRIVATE FUNCTIONS
***************************************************************************/
/**************************************************************************/
/*!
@brief Writes an 8 bit value over I2C
*/
/**************************************************************************/
static void writeCommand(byte reg, byte value)
{
Wire.beginTransmission((uint8_t)BMP085_ADDRESS);
#if ARDUINO >= 100
Wire.write((uint8_t)reg);
Wire.write((uint8_t)value);
#else
Wire.send(reg);
Wire.send(value);
#endif
Wire.endTransmission();
}
/**************************************************************************/
/*!
@brief Reads an 8 bit value over I2C
*/
/**************************************************************************/
static void read8(byte reg, uint8_t *value)
{
Wire.beginTransmission((uint8_t)BMP085_ADDRESS);
#if ARDUINO >= 100
Wire.write((uint8_t)reg);
#else
Wire.send(reg);
#endif
Wire.endTransmission();
Wire.requestFrom((uint8_t)BMP085_ADDRESS, (byte)1);
#if ARDUINO >= 100
*value = Wire.read();
#else
*value = Wire.receive();
#endif
Wire.endTransmission();
}
/**************************************************************************/
/*!
@brief Reads a 16 bit value over I2C
*/
/**************************************************************************/
static void read16(byte reg, uint16_t *value)
{
Wire.beginTransmission((uint8_t)BMP085_ADDRESS);
#if ARDUINO >= 100
Wire.write((uint8_t)reg);
#else
Wire.send(reg);
#endif
Wire.endTransmission();
Wire.requestFrom((uint8_t)BMP085_ADDRESS, (byte)2);
#if ARDUINO >= 100
*value = (Wire.read() << 8) | Wire.read();
#else
*value = (Wire.receive() << 8) | Wire.receive();
#endif
Wire.endTransmission();
}
/**************************************************************************/
/*!
@brief Reads a signed 16 bit value over I2C
*/
/**************************************************************************/
static void readS16(byte reg, int16_t *value)
{
uint16_t i;
read16(reg, &i);
*value = (int16_t)i;
}
/**************************************************************************/
/*!
@brief Reads the factory-set coefficients
*/
/**************************************************************************/
static void readCoefficients(void)
{
#if BMP085_USE_DATASHEET_VALS
_bmp085_coeffs.ac1 = 408;
_bmp085_coeffs.ac2 = -72;
_bmp085_coeffs.ac3 = -14383;
_bmp085_coeffs.ac4 = 32741;
_bmp085_coeffs.ac5 = 32757;
_bmp085_coeffs.ac6 = 23153;
_bmp085_coeffs.b1 = 6190;
_bmp085_coeffs.b2 = 4;
_bmp085_coeffs.mb = -32768;
_bmp085_coeffs.mc = -8711;
_bmp085_coeffs.md = 2868;
_bmp085Mode = 0;
#else
readS16(BMP085_REGISTER_CAL_AC1, &_bmp085_coeffs.ac1);
readS16(BMP085_REGISTER_CAL_AC2, &_bmp085_coeffs.ac2);
readS16(BMP085_REGISTER_CAL_AC3, &_bmp085_coeffs.ac3);
read16(BMP085_REGISTER_CAL_AC4, &_bmp085_coeffs.ac4);
read16(BMP085_REGISTER_CAL_AC5, &_bmp085_coeffs.ac5);
read16(BMP085_REGISTER_CAL_AC6, &_bmp085_coeffs.ac6);
readS16(BMP085_REGISTER_CAL_B1, &_bmp085_coeffs.b1);
readS16(BMP085_REGISTER_CAL_B2, &_bmp085_coeffs.b2);
readS16(BMP085_REGISTER_CAL_MB, &_bmp085_coeffs.mb);
readS16(BMP085_REGISTER_CAL_MC, &_bmp085_coeffs.mc);
readS16(BMP085_REGISTER_CAL_MD, &_bmp085_coeffs.md);
#endif
}
/**************************************************************************/
/*!
*/
/**************************************************************************/
static void readRawTemperature(int32_t *temperature)
{
#if BMP085_USE_DATASHEET_VALS
*temperature = 27898;
#else
uint16_t t;
writeCommand(BMP085_REGISTER_CONTROL, BMP085_REGISTER_READTEMPCMD);
delay(5);
read16(BMP085_REGISTER_TEMPDATA, &t);
*temperature = t;
#endif
}
/**************************************************************************/
/*!
*/
/**************************************************************************/
static void readRawPressure(int32_t *pressure)
{
#if BMP085_USE_DATASHEET_VALS
*pressure = 23843;
#else
uint8_t p8;
uint16_t p16;
int32_t p32;
writeCommand(BMP085_REGISTER_CONTROL, BMP085_REGISTER_READPRESSURECMD + (_bmp085Mode << 6));
switch(_bmp085Mode)
{
case BMP085_MODE_ULTRALOWPOWER:
delay(5);
break;
case BMP085_MODE_STANDARD:
delay(8);
break;
case BMP085_MODE_HIGHRES:
delay(14);
break;
case BMP085_MODE_ULTRAHIGHRES:
default:
delay(26);
break;
}
read16(BMP085_REGISTER_PRESSUREDATA, &p16);
p32 = (uint32_t)p16 << 8;
read8(BMP085_REGISTER_PRESSUREDATA+2, &p8);
p32 += p8;
p32 >>= (8 - _bmp085Mode);
*pressure = p32;
#endif
}
/**************************************************************************/
/*!
@brief Compute B5 coefficient used in temperature & pressure calcs.
*/
/**************************************************************************/
int32_t Adafruit_BMP085_Unified::computeB5(int32_t ut) {
int32_t X1 = (ut - (int32_t)_bmp085_coeffs.ac6) * ((int32_t)_bmp085_coeffs.ac5) >> 15;
int32_t X2 = ((int32_t)_bmp085_coeffs.mc << 11) / (X1+(int32_t)_bmp085_coeffs.md);
return X1 + X2;
}
/***************************************************************************
CONSTRUCTOR
***************************************************************************/
/**************************************************************************/
/*!
@brief Instantiates a new Adafruit_BMP085_Unified class
*/
/**************************************************************************/
Adafruit_BMP085_Unified::Adafruit_BMP085_Unified(int32_t sensorID) {
_sensorID = sensorID;
}
/***************************************************************************
PUBLIC FUNCTIONS
***************************************************************************/
/**************************************************************************/
/*!
@brief Setups the HW
*/
/**************************************************************************/
bool Adafruit_BMP085_Unified::begin(bmp085_mode_t mode)
{
// Enable I2C
Wire.begin();
/* Mode boundary check */
if ((mode > BMP085_MODE_ULTRAHIGHRES) || (mode < 0))
{
mode = BMP085_MODE_ULTRAHIGHRES;
}
/* Make sure we have the right device */
uint8_t id;
read8(BMP085_REGISTER_CHIPID, &id);
if(id != 0x55)
{
return false;
}
/* Set the mode indicator */
_bmp085Mode = mode;
/* Coefficients need to be read once */
readCoefficients();
return true;
}
/**************************************************************************/
/*!
@brief Gets the compensated pressure level in kPa
*/
/**************************************************************************/
void Adafruit_BMP085_Unified::getPressure(float *pressure)
{
int32_t ut = 0, up = 0, compp = 0;
int32_t x1, x2, b5, b6, x3, b3, p;
uint32_t b4, b7;
/* Get the raw pressure and temperature values */
readRawTemperature(&ut);
readRawPressure(&up);
/* Temperature compensation */
b5 = computeB5(ut);
/* Pressure compensation */
b6 = b5 - 4000;
x1 = (_bmp085_coeffs.b2 * ((b6 * b6) >> 12)) >> 11;
x2 = (_bmp085_coeffs.ac2 * b6) >> 11;
x3 = x1 + x2;
b3 = (((((int32_t) _bmp085_coeffs.ac1) * 4 + x3) << _bmp085Mode) + 2) >> 2;
x1 = (_bmp085_coeffs.ac3 * b6) >> 13;
x2 = (_bmp085_coeffs.b1 * ((b6 * b6) >> 12)) >> 16;
x3 = ((x1 + x2) + 2) >> 2;
b4 = (_bmp085_coeffs.ac4 * (uint32_t) (x3 + 32768)) >> 15;
b7 = ((uint32_t) (up - b3) * (50000 >> _bmp085Mode));
if (b7 < 0x80000000)
{
p = (b7 << 1) / b4;
}
else
{
p = (b7 / b4) << 1;
}
x1 = (p >> 8) * (p >> 8);
x1 = (x1 * 3038) >> 16;
x2 = (-7357 * p) >> 16;
compp = p + ((x1 + x2 + 3791) >> 4);
/* Assign compensated pressure value */
*pressure = compp;
}
/**************************************************************************/
/*!
@brief Reads the temperatures in degrees Celsius
*/
/**************************************************************************/
void Adafruit_BMP085_Unified::getTemperature(float *temp)
{
int32_t UT, X1, X2, B5; // following ds convention
float t;
readRawTemperature(&UT);
#if BMP085_USE_DATASHEET_VALS
// use datasheet numbers!
UT = 27898;
_bmp085_coeffs.ac6 = 23153;
_bmp085_coeffs.ac5 = 32757;
_bmp085_coeffs.mc = -8711;
_bmp085_coeffs.md = 2868;
#endif
B5 = computeB5(UT);
t = (B5+8) >> 4;
t /= 10;
*temp = t;
}
/**************************************************************************/
/*!
Calculates the altitude (in meters) from the specified atmospheric
pressure (in hPa), sea-level pressure (in hPa), and temperature (in <20>C)
@param seaLevel Sea-level pressure in hPa
@param atmospheric Atmospheric pressure in hPa
@param temp Temperature in degrees Celsius
*/
/**************************************************************************/
float Adafruit_BMP085_Unified::pressureToAltitude(float seaLevel, float atmospheric, float temp)
{
/* Hyposometric formula: */
/* */
/* ((P0/P)^(1/5.257) - 1) * (T + 273.15) */
/* h = ------------------------------------- */
/* 0.0065 */
/* */
/* where: h = height (in meters) */
/* P0 = sea-level pressure (in hPa) */
/* P = atmospheric pressure (in hPa) */
/* T = temperature (in <20>C) */
return (((float)pow((seaLevel/atmospheric), 0.190223F) - 1.0F)
* (temp + 273.15F)) / 0.0065F;
}
float Adafruit_BMP085_Unified::seaLevelForAltitude(float altitude, float atmospheric, float temp)
{
/* Hyposometric formula: */
/* */
/* P0=((((h*0.0065)/(temp + 273.15F))+1)^(^/0.190223F))*P */
/* */
/* where: h = height (in meters) */
/* P0 = sea-level pressure (in hPa) */
/* P = atmospheric pressure (in hPa) */
/* T = temperature (in <20>C) */
return (float)pow((((altitude*0.0065)/(temp + 273.15F))+1), (1.0/0.190223F))*atmospheric;
}
/**************************************************************************/
/*!
@brief Provides the sensor_t data for this sensor
*/
/**************************************************************************/
void Adafruit_BMP085_Unified::getSensor(sensor_t *sensor)
{
/* Clear the sensor_t object */
memset(sensor, 0, sizeof(sensor_t));
/* Insert the sensor name in the fixed length char array */
strncpy (sensor->name, "BMP085", sizeof(sensor->name) - 1);
sensor->name[sizeof(sensor->name)- 1] = 0;
sensor->version = 1;
sensor->sensor_id = _sensorID;
sensor->type = SENSOR_TYPE_PRESSURE;
sensor->min_delay = 0;
sensor->max_value = 300.0F; // 300..1100 hPa
sensor->min_value = 1100.0F;
sensor->resolution = 0.01F; // Datasheet states 0.01 hPa resolution
}
/**************************************************************************/
/*!
@brief Reads the sensor and returns the data as a sensors_event_t
*/
/**************************************************************************/
void Adafruit_BMP085_Unified::getEvent(sensors_event_t *event)
{
float pressure_kPa;
/* Clear the event */
memset(event, 0, sizeof(sensors_event_t));
event->version = sizeof(sensors_event_t);
event->sensor_id = _sensorID;
event->type = SENSOR_TYPE_PRESSURE;
event->timestamp = 0;
getPressure(&pressure_kPa);
event->pressure = pressure_kPa / 100.0F;
}
Reference in New Issue View Git Blame Copy Permalink