Samir Bouaziz / Mbed 2 deprecated test_bmp085

test capteurs BMP085 météo

Dependencies:   mbed

BMP085_sam.cpp@0:ad2afb285975, 2011-10-14 (annotated)

Committer:
bouaziz
Date:
Fri Oct 14 18:44:39 2011 +0000
Revision:
0:ad2afb285975
v1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bouaziz 0:ad2afb285975 1 /*
bouaziz 0:ad2afb285975 2 * mbed library to use a Bosch Sensortec BMP085 sensor
bouaziz 0:ad2afb285975 3 * Copyright (c) 2010 Hiroshi Suga
bouaziz 0:ad2afb285975 4 * Released under the MIT License: http://mbed.org/license/mit
bouaziz 0:ad2afb285975 5 */
bouaziz 0:ad2afb285975 6
bouaziz 0:ad2afb285975 7 /** @file BMP085.cpp
bouaziz 0:ad2afb285975 8 * @brief mbed library to use a Bosch Sensortec BMP085 sensor
bouaziz 0:ad2afb285975 9 * barometric pressure sensor BMP085 (Bosch Sensortec)
bouaziz 0:ad2afb285975 10 * interface: I2C digital
bouaziz 0:ad2afb285975 11 */
bouaziz 0:ad2afb285975 12
bouaziz 0:ad2afb285975 13 #include "mbed.h"
bouaziz 0:ad2afb285975 14 #include "BMP085.h"
bouaziz 0:ad2afb285975 15
bouaziz 0:ad2afb285975 16 #define WEATHER_BMP085 0xee
bouaziz 0:ad2afb285975 17 #define xpow(x, y) ((long)1 << y)
bouaziz 0:ad2afb285975 18
bouaziz 0:ad2afb285975 19 /**
bouaziz 0:ad2afb285975 20 * @brief Initializes interface (private I2C)
bouaziz 0:ad2afb285975 21 * @param p_sda port of I2C SDA
bouaziz 0:ad2afb285975 22 * @param p_scl port of I2C SCL
bouaziz 0:ad2afb285975 23 * @param p_oss parameter of OSS
bouaziz 0:ad2afb285975 24 */
bouaziz 0:ad2afb285975 25 BMP085::BMP085 (PinName p_sda, PinName p_scl, BMP085_oss p_oss) : i2c(p_sda, p_scl) {
bouaziz 0:ad2afb285975 26 init(p_oss);
bouaziz 0:ad2afb285975 27 }
bouaziz 0:ad2afb285975 28
bouaziz 0:ad2afb285975 29 /**
bouaziz 0:ad2afb285975 30 * @brief Initializes interface (public I2C)
bouaziz 0:ad2afb285975 31 * @param p_i2c instance of I2C class
bouaziz 0:ad2afb285975 32 * @param p_oss parameter of OSS
bouaziz 0:ad2afb285975 33 */
bouaziz 0:ad2afb285975 34 BMP085::BMP085 (I2C& p_i2c, BMP085_oss p_oss) : i2c(p_i2c) {
bouaziz 0:ad2afb285975 35 init(p_oss);
bouaziz 0:ad2afb285975 36 }
bouaziz 0:ad2afb285975 37
bouaziz 0:ad2afb285975 38 /**
bouaziz 0:ad2afb285975 39 * @brief Get temperature
bouaziz 0:ad2afb285975 40 * @return temperature (`C)
bouaziz 0:ad2afb285975 41 */
bouaziz 0:ad2afb285975 42 float BMP085::get_temperature() {
bouaziz 0:ad2afb285975 43 return temperature;
bouaziz 0:ad2afb285975 44 }
bouaziz 0:ad2afb285975 45
bouaziz 0:ad2afb285975 46 /**
bouaziz 0:ad2afb285975 47 * @brief Get pressure
bouaziz 0:ad2afb285975 48 * @return pressure (hPa)
bouaziz 0:ad2afb285975 49 */
bouaziz 0:ad2afb285975 50 float BMP085::get_pressure() {
bouaziz 0:ad2afb285975 51 return pressure;
bouaziz 0:ad2afb285975 52 }
bouaziz 0:ad2afb285975 53
bouaziz 0:ad2afb285975 54 /**
bouaziz 0:ad2afb285975 55 * @brief Update results
bouaziz 0:ad2afb285975 56 */
bouaziz 0:ad2afb285975 57 void BMP085::update () {
bouaziz 0:ad2afb285975 58 long t, p, ut, up, x1, x2, x3, b3, b5, b6;
bouaziz 0:ad2afb285975 59 unsigned long b4, b7;
bouaziz 0:ad2afb285975 60
bouaziz 0:ad2afb285975 61 twi_writechar(WEATHER_BMP085, 0xf4, 0x2e);
bouaziz 0:ad2afb285975 62 wait(0.01);
bouaziz 0:ad2afb285975 63 ut = twi_readshort(WEATHER_BMP085, 0xf6);
bouaziz 0:ad2afb285975 64
bouaziz 0:ad2afb285975 65 twi_writechar(WEATHER_BMP085, 0xf4, 0x34 | (oss << 6));
bouaziz 0:ad2afb285975 66 wait(0.05);
bouaziz 0:ad2afb285975 67 up = twi_readlong(WEATHER_BMP085, 0xf6) >> (8 - oss);
bouaziz 0:ad2afb285975 68
bouaziz 0:ad2afb285975 69 x1 = ((ut - ac6) * ac5) / xpow(2, 15);
bouaziz 0:ad2afb285975 70 x2 = ((long)mc * xpow(2, 11)) / (x1 + md);
bouaziz 0:ad2afb285975 71 b5 = x1 + x2;
bouaziz 0:ad2afb285975 72 t = (b5 + 8) / xpow(2, 4);
bouaziz 0:ad2afb285975 73 temperature = (float)t / 10.0;
bouaziz 0:ad2afb285975 74
bouaziz 0:ad2afb285975 75 b6 = b5 - 4000;
bouaziz 0:ad2afb285975 76 x1 = (b2 * (b6 * b6 / xpow(2, 12))) / xpow(2, 11);
bouaziz 0:ad2afb285975 77 x2 = (ac2 * b6) / xpow(2, 11);
bouaziz 0:ad2afb285975 78 x3 = x1 + x2;
bouaziz 0:ad2afb285975 79 b3 = ((((unsigned long)ac1 * 4 + x3) << oss) + 2) / 4;
bouaziz 0:ad2afb285975 80 x1 = ac3 * b6 / xpow(2, 13);
bouaziz 0:ad2afb285975 81 x2 = (b1 * (b6 * b6 / xpow(2, 12))) / xpow(2, 16);
bouaziz 0:ad2afb285975 82 x3 = ((x1 + x2) + 2) / xpow(2, 2);
bouaziz 0:ad2afb285975 83 b4 = (ac4 * (unsigned long)(x3 + 32768)) / xpow(2, 15);
bouaziz 0:ad2afb285975 84 b7 = ((unsigned long)up - b3) * (50000 >> oss);
bouaziz 0:ad2afb285975 85 if (b7 < (unsigned long)0x80000000) {
bouaziz 0:ad2afb285975 86 p = (b7 * 2) / b4;
bouaziz 0:ad2afb285975 87 } else {
bouaziz 0:ad2afb285975 88 p = (b7 / b4) * 2;
bouaziz 0:ad2afb285975 89 }
bouaziz 0:ad2afb285975 90 x1 = (p / xpow(2, 8)) * (p / xpow(2, 8));
bouaziz 0:ad2afb285975 91 x1 = (x1 * 3038) / xpow(2, 16);
bouaziz 0:ad2afb285975 92 x2 = (-7357 * p) / xpow(2, 16);
bouaziz 0:ad2afb285975 93 p = p + (x1 + x2 + 3791) / xpow(2, 4);
bouaziz 0:ad2afb285975 94 pressure = (float)p / 100.0;
bouaziz 0:ad2afb285975 95 }
bouaziz 0:ad2afb285975 96
bouaziz 0:ad2afb285975 97 void BMP085::init (BMP085_oss p_oss) {
bouaziz 0:ad2afb285975 98 ac1 = twi_readshort(WEATHER_BMP085, 0xaa);
bouaziz 0:ad2afb285975 99 ac2 = twi_readshort(WEATHER_BMP085, 0xac);
bouaziz 0:ad2afb285975 100 ac3 = twi_readshort(WEATHER_BMP085, 0xae);
bouaziz 0:ad2afb285975 101 ac4 = twi_readshort(WEATHER_BMP085, 0xb0);
bouaziz 0:ad2afb285975 102 ac5 = twi_readshort(WEATHER_BMP085, 0xb2);
bouaziz 0:ad2afb285975 103 ac6 = twi_readshort(WEATHER_BMP085, 0xb4);
bouaziz 0:ad2afb285975 104 b1 = twi_readshort(WEATHER_BMP085, 0xb6);
bouaziz 0:ad2afb285975 105 b2 = twi_readshort(WEATHER_BMP085, 0xb8);
bouaziz 0:ad2afb285975 106 mb = twi_readshort(WEATHER_BMP085, 0xba);
bouaziz 0:ad2afb285975 107 mc = twi_readshort(WEATHER_BMP085, 0xbc);
bouaziz 0:ad2afb285975 108 md = twi_readshort(WEATHER_BMP085, 0xbe);
bouaziz 0:ad2afb285975 109 oss = p_oss;
bouaziz 0:ad2afb285975 110 }
bouaziz 0:ad2afb285975 111
bouaziz 0:ad2afb285975 112 unsigned short BMP085::twi_readshort (int id, int addr) {
bouaziz 0:ad2afb285975 113 unsigned short i;
bouaziz 0:ad2afb285975 114
bouaziz 0:ad2afb285975 115 i2c.start();
bouaziz 0:ad2afb285975 116 i2c.write(id);
bouaziz 0:ad2afb285975 117 i2c.write(addr);
bouaziz 0:ad2afb285975 118
bouaziz 0:ad2afb285975 119 i2c.start();
bouaziz 0:ad2afb285975 120 i2c.write(id | 1);
bouaziz 0:ad2afb285975 121 i = i2c.read(1) << 8;
bouaziz 0:ad2afb285975 122 i |= i2c.read(0);
bouaziz 0:ad2afb285975 123 i2c.stop();
bouaziz 0:ad2afb285975 124
bouaziz 0:ad2afb285975 125 return i;
bouaziz 0:ad2afb285975 126 }
bouaziz 0:ad2afb285975 127
bouaziz 0:ad2afb285975 128 unsigned long BMP085::twi_readlong (int id, int addr) {
bouaziz 0:ad2afb285975 129 unsigned long i;
bouaziz 0:ad2afb285975 130
bouaziz 0:ad2afb285975 131 i2c.start();
bouaziz 0:ad2afb285975 132 i2c.write(id);
bouaziz 0:ad2afb285975 133 i2c.write(addr);
bouaziz 0:ad2afb285975 134
bouaziz 0:ad2afb285975 135 i2c.start();
bouaziz 0:ad2afb285975 136 i2c.write(id | 1);
bouaziz 0:ad2afb285975 137 i = i2c.read(1) << 16;
bouaziz 0:ad2afb285975 138 i |= i2c.read(1) << 8;
bouaziz 0:ad2afb285975 139 i |= i2c.read(0);
bouaziz 0:ad2afb285975 140 i2c.stop();
bouaziz 0:ad2afb285975 141
bouaziz 0:ad2afb285975 142 return i;
bouaziz 0:ad2afb285975 143 }
bouaziz 0:ad2afb285975 144
bouaziz 0:ad2afb285975 145 void BMP085::twi_writechar (int id, int addr, int dat) {
bouaziz 0:ad2afb285975 146
bouaziz 0:ad2afb285975 147 i2c.start();
bouaziz 0:ad2afb285975 148 i2c.write(id);
bouaziz 0:ad2afb285975 149 i2c.write(addr);
bouaziz 0:ad2afb285975 150 i2c.write(dat);
bouaziz 0:ad2afb285975 151 i2c.stop();
bouaziz 0:ad2afb285975 152 }