Hilton Tnunay / MS5611

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MS5611.cpp@1:8ebf0430f788, 2014-01-17 (annotated)

Committer:
hiltontnunay
Date:
Fri Jan 17 13:45:43 2014 +0000
Revision:
1:8ebf0430f788
Parent:
0:669dfadf96c5 
ms5611

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gmatjuara 0:669dfadf96c5 1 /*
gmatjuara 0:669dfadf96c5 2 * mbed library to use a Bosch Sensortec MS5611 sensor
gmatjuara 0:669dfadf96c5 3 * Copyright (c) 2010 Hiroshi Suga
gmatjuara 0:669dfadf96c5 4 * Released under the MIT License: http://mbed.org/license/mit
gmatjuara 0:669dfadf96c5 5 */
gmatjuara 0:669dfadf96c5 6
gmatjuara 0:669dfadf96c5 7 /** @file MS5611.cpp
gmatjuara 0:669dfadf96c5 8 * @brief mbed library to use a Bosch Sensortec MS5611 sensor
gmatjuara 0:669dfadf96c5 9 * barometric pressure sensor MS5611 (Bosch Sensortec)
gmatjuara 0:669dfadf96c5 10 * interface: I2C digital
gmatjuara 0:669dfadf96c5 11 */
gmatjuara 0:669dfadf96c5 12
gmatjuara 0:669dfadf96c5 13 #include "mbed.h"
gmatjuara 0:669dfadf96c5 14 #include "MS5611.h"
gmatjuara 0:669dfadf96c5 15
gmatjuara 0:669dfadf96c5 16 #define WEATHER_MS5611 0xee
gmatjuara 0:669dfadf96c5 17 #define xpow(x, y) ((long)1 << y)
gmatjuara 0:669dfadf96c5 18
gmatjuara 0:669dfadf96c5 19 /**
gmatjuara 0:669dfadf96c5 20 * @brief Initializes interface (private I2C)
gmatjuara 0:669dfadf96c5 21 * @param p_sda port of I2C SDA
gmatjuara 0:669dfadf96c5 22 * @param p_scl port of I2C SCL
gmatjuara 0:669dfadf96c5 23 * @param p_oss parameter of OSS
gmatjuara 0:669dfadf96c5 24 */
gmatjuara 0:669dfadf96c5 25 MS5611::MS5611 (PinName p_sda, PinName p_scl, MS5611_oss p_oss) : i2c(p_sda, p_scl) {
gmatjuara 0:669dfadf96c5 26 init(p_oss);
gmatjuara 0:669dfadf96c5 27 }
gmatjuara 0:669dfadf96c5 28
gmatjuara 0:669dfadf96c5 29 /**
gmatjuara 0:669dfadf96c5 30 * @brief Initializes interface (public I2C)
gmatjuara 0:669dfadf96c5 31 * @param p_i2c instance of I2C class
gmatjuara 0:669dfadf96c5 32 * @param p_oss parameter of OSS
gmatjuara 0:669dfadf96c5 33 */
gmatjuara 0:669dfadf96c5 34 MS5611::MS5611 (I2C& p_i2c, MS5611_oss p_oss) : i2c(p_i2c) {
gmatjuara 0:669dfadf96c5 35 init(p_oss);
gmatjuara 0:669dfadf96c5 36 }
gmatjuara 0:669dfadf96c5 37
gmatjuara 0:669dfadf96c5 38 /**
gmatjuara 0:669dfadf96c5 39 * @brief Get temperature
gmatjuara 0:669dfadf96c5 40 * @return temperature (`C)
gmatjuara 0:669dfadf96c5 41 */
hiltontnunay 1:8ebf0430f788 42 float MS5611::getTemperature() {
gmatjuara 0:669dfadf96c5 43 return temperature;
gmatjuara 0:669dfadf96c5 44 }
gmatjuara 0:669dfadf96c5 45
gmatjuara 0:669dfadf96c5 46 /**
gmatjuara 0:669dfadf96c5 47 * @brief Get pressure
gmatjuara 0:669dfadf96c5 48 * @return pressure (hPa)
gmatjuara 0:669dfadf96c5 49 */
hiltontnunay 1:8ebf0430f788 50 float MS5611::getPressure() {
gmatjuara 0:669dfadf96c5 51 return pressure;
gmatjuara 0:669dfadf96c5 52 }
gmatjuara 0:669dfadf96c5 53
gmatjuara 0:669dfadf96c5 54 /**
gmatjuara 0:669dfadf96c5 55 * @brief Update results
gmatjuara 0:669dfadf96c5 56 */
gmatjuara 0:669dfadf96c5 57 void MS5611::update () {
gmatjuara 0:669dfadf96c5 58 long t, p, ut, up, x1, x2, x3, b3, b5, b6;
gmatjuara 0:669dfadf96c5 59 unsigned long b4, b7;
gmatjuara 0:669dfadf96c5 60
gmatjuara 0:669dfadf96c5 61 twi_writechar(WEATHER_MS5611, 0xf4, 0x2e);
gmatjuara 0:669dfadf96c5 62 wait(0.0045); //wait(0.01);
gmatjuara 0:669dfadf96c5 63 ut = twi_readshort(WEATHER_MS5611, 0xf6);
gmatjuara 0:669dfadf96c5 64
gmatjuara 0:669dfadf96c5 65 twi_writechar(WEATHER_MS5611, 0xf4, 0x34 | (oss << 6));
gmatjuara 0:669dfadf96c5 66 wait(0.0045); //wait(0.05);
gmatjuara 0:669dfadf96c5 67 up = twi_readlong(WEATHER_MS5611, 0xf6) >> (8 - oss);
gmatjuara 0:669dfadf96c5 68
gmatjuara 0:669dfadf96c5 69 x1 = (ut - ac6) * ac5 / xpow(2, 15);
gmatjuara 0:669dfadf96c5 70 x2 = (long)mc * xpow(2, 11) / (x1 + md);
gmatjuara 0:669dfadf96c5 71 b5 = x1 + x2;
gmatjuara 0:669dfadf96c5 72 t = (b5 + 8) / xpow(2, 4);
gmatjuara 0:669dfadf96c5 73 temperature = (float)t / 10.0;
gmatjuara 0:669dfadf96c5 74
gmatjuara 0:669dfadf96c5 75 b6 = b5 - 4000;
gmatjuara 0:669dfadf96c5 76 x1 = (b2 * (b6 * b6 / xpow(2, 12))) / xpow(2, 11);
gmatjuara 0:669dfadf96c5 77 x2 = ac2 * b6 / xpow(2, 11);
gmatjuara 0:669dfadf96c5 78 x3 = x1 + x2;
gmatjuara 0:669dfadf96c5 79 b3 = ((((unsigned long)ac1 * 4 + x3) << oss) + 2) / 4;
gmatjuara 0:669dfadf96c5 80 x1 = ac3 * b6 / xpow(2, 13);
gmatjuara 0:669dfadf96c5 81 x2 = (b1 * (b6 * b6 / xpow(2, 12))) / xpow(2, 16);
gmatjuara 0:669dfadf96c5 82 x3 = ((x1 + x2) + 2) / xpow(2, 2);
gmatjuara 0:669dfadf96c5 83 b4 = ac4 * (unsigned long)(x3 + 32768) / xpow(2, 15);
gmatjuara 0:669dfadf96c5 84 b7 = ((unsigned long)up - b3) * (50000 >> oss);
gmatjuara 0:669dfadf96c5 85 if (b7 < (unsigned long)0x80000000) {
gmatjuara 0:669dfadf96c5 86 p = (b7 * 2) / b4;
gmatjuara 0:669dfadf96c5 87 } else {
gmatjuara 0:669dfadf96c5 88 p = (b7 / b4) * 2;
gmatjuara 0:669dfadf96c5 89 }
gmatjuara 0:669dfadf96c5 90 x1 = (p / xpow(2, 8)) * (p / xpow(2, 8));
gmatjuara 0:669dfadf96c5 91 x1 = (x1 * 3038) / xpow(2, 16);
gmatjuara 0:669dfadf96c5 92 x2 = (-7357 * p) / xpow(2, 16);
gmatjuara 0:669dfadf96c5 93 p = p + (x1 + x2 + 3791) / xpow(2, 4);
gmatjuara 0:669dfadf96c5 94 pressure = (float)p / 100.0;
gmatjuara 0:669dfadf96c5 95 }
gmatjuara 0:669dfadf96c5 96
gmatjuara 0:669dfadf96c5 97 void MS5611::init (MS5611_oss p_oss) {
gmatjuara 0:669dfadf96c5 98 ac1 = twi_readshort(WEATHER_MS5611, 0xaa);
gmatjuara 0:669dfadf96c5 99 ac2 = twi_readshort(WEATHER_MS5611, 0xac);
gmatjuara 0:669dfadf96c5 100 ac3 = twi_readshort(WEATHER_MS5611, 0xae);
gmatjuara 0:669dfadf96c5 101 ac4 = twi_readshort(WEATHER_MS5611, 0xb0);
gmatjuara 0:669dfadf96c5 102 ac5 = twi_readshort(WEATHER_MS5611, 0xb2);
gmatjuara 0:669dfadf96c5 103 ac6 = twi_readshort(WEATHER_MS5611, 0xb4);
gmatjuara 0:669dfadf96c5 104 b1 = twi_readshort(WEATHER_MS5611, 0xb6);
gmatjuara 0:669dfadf96c5 105 b2 = twi_readshort(WEATHER_MS5611, 0xb8);
gmatjuara 0:669dfadf96c5 106 mb = twi_readshort(WEATHER_MS5611, 0xba);
gmatjuara 0:669dfadf96c5 107 mc = twi_readshort(WEATHER_MS5611, 0xbc);
gmatjuara 0:669dfadf96c5 108 md = twi_readshort(WEATHER_MS5611, 0xbe);
gmatjuara 0:669dfadf96c5 109 oss = p_oss;
gmatjuara 0:669dfadf96c5 110 }
gmatjuara 0:669dfadf96c5 111
gmatjuara 0:669dfadf96c5 112 unsigned short MS5611::twi_readshort (int id, int addr) {
gmatjuara 0:669dfadf96c5 113 unsigned short i;
gmatjuara 0:669dfadf96c5 114
gmatjuara 0:669dfadf96c5 115 i2c.start();
gmatjuara 0:669dfadf96c5 116 i2c.write(id);
gmatjuara 0:669dfadf96c5 117 i2c.write(addr);
gmatjuara 0:669dfadf96c5 118
gmatjuara 0:669dfadf96c5 119 i2c.start();
gmatjuara 0:669dfadf96c5 120 i2c.write(id | 1);
gmatjuara 0:669dfadf96c5 121 i = i2c.read(1) << 8;
gmatjuara 0:669dfadf96c5 122 i |= i2c.read(0);
gmatjuara 0:669dfadf96c5 123 i2c.stop();
gmatjuara 0:669dfadf96c5 124
gmatjuara 0:669dfadf96c5 125 return i;
gmatjuara 0:669dfadf96c5 126 }
gmatjuara 0:669dfadf96c5 127
gmatjuara 0:669dfadf96c5 128 unsigned long MS5611::twi_readlong (int id, int addr) {
gmatjuara 0:669dfadf96c5 129 unsigned long i;
gmatjuara 0:669dfadf96c5 130
gmatjuara 0:669dfadf96c5 131 i2c.start();
gmatjuara 0:669dfadf96c5 132 i2c.write(id);
gmatjuara 0:669dfadf96c5 133 i2c.write(addr);
gmatjuara 0:669dfadf96c5 134
gmatjuara 0:669dfadf96c5 135 i2c.start();
gmatjuara 0:669dfadf96c5 136 i2c.write(id | 1);
gmatjuara 0:669dfadf96c5 137 i = i2c.read(1) << 16;
gmatjuara 0:669dfadf96c5 138 i |= i2c.read(1) << 8;
gmatjuara 0:669dfadf96c5 139 i |= i2c.read(0);
gmatjuara 0:669dfadf96c5 140 i2c.stop();
gmatjuara 0:669dfadf96c5 141
gmatjuara 0:669dfadf96c5 142 return i;
gmatjuara 0:669dfadf96c5 143 }
gmatjuara 0:669dfadf96c5 144
gmatjuara 0:669dfadf96c5 145 void MS5611::twi_writechar (int id, int addr, int dat) {
gmatjuara 0:669dfadf96c5 146
gmatjuara 0:669dfadf96c5 147 i2c.start();
gmatjuara 0:669dfadf96c5 148 i2c.write(id);
gmatjuara 0:669dfadf96c5 149 i2c.write(addr);
gmatjuara 0:669dfadf96c5 150 i2c.write(dat);
gmatjuara 0:669dfadf96c5 151 i2c.stop();
gmatjuara 0:669dfadf96c5 152 }