Jarkko Säkkinen / Mbed 2 deprecated TEMP_YM2

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Dependencies:   BLE_API TMP_nrf51 mbed nRF51822

Fork of VTT_NODEV3_BMP180_Si7021 by Juho Eskeli

BMP180.h@3:101b0f081435, 2016-05-27 (annotated)

Committer:
JarkkoS
Date:
Fri May 27 07:38:42 2016 +0000
Revision:
3:101b0f081435
Parent:
2:b221ba23b37f 
VTT TinyNodeV2, slightly modified code from example (https://developer.mbed.org/users/jejuho/code/VTT_NODEV3_BMP180_Si7021)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jejuho 2:b221ba23b37f 1 #ifndef BMP180_H
jejuho 2:b221ba23b37f 2 #define BMP180_H
jejuho 2:b221ba23b37f 3
jejuho 2:b221ba23b37f 4 #include "mbed.h"
jejuho 2:b221ba23b37f 5
jejuho 2:b221ba23b37f 6 #define BMP180_ADDRESS 0x77<<1 // I2C address of BMP180, eight bit address on mbed
jejuho 2:b221ba23b37f 7 #define BMP180_WHO_AM_I 0xD0 // WHO_AM_I id of BMP180, should return 0x55
jejuho 2:b221ba23b37f 8 #define BMP180_RESET 0xE0
jejuho 2:b221ba23b37f 9 #define BMP180_CONTROL 0xF4
jejuho 2:b221ba23b37f 10 #define BMP180_OUT_MSB 0xF6
jejuho 2:b221ba23b37f 11 #define BMP180_OUT_LSB 0xF7
jejuho 2:b221ba23b37f 12 #define BMP180_OUT_XLSB 0xF8
jejuho 2:b221ba23b37f 13
jejuho 2:b221ba23b37f 14 // Set initial input parameters
jejuho 2:b221ba23b37f 15
jejuho 2:b221ba23b37f 16 enum OSS { // BMP-085 sampling rate
jejuho 2:b221ba23b37f 17 OSS_0 = 0, // 4.5 ms conversion time
jejuho 2:b221ba23b37f 18 OSS_1, // 7.5
jejuho 2:b221ba23b37f 19 OSS_2, // 13.5
jejuho 2:b221ba23b37f 20 OSS_3 // 25.5
jejuho 2:b221ba23b37f 21 };
jejuho 2:b221ba23b37f 22
jejuho 2:b221ba23b37f 23 uint8_t OSS = OSS_3; // maximum pressure resolution
jejuho 2:b221ba23b37f 24
jejuho 2:b221ba23b37f 25 // These are constants used to calculate the temperature and pressure from the BMP-180 sensor
jejuho 2:b221ba23b37f 26 int16_t ac1, ac2, ac3, b1, b2, mb, mc, md, b5;
jejuho 2:b221ba23b37f 27 uint16_t ac4, ac5, ac6;
jejuho 2:b221ba23b37f 28
jejuho 2:b221ba23b37f 29 class BMP180 {
jejuho 2:b221ba23b37f 30
jejuho 2:b221ba23b37f 31 private:
jejuho 2:b221ba23b37f 32 //Set up I2C, (SDA,SCL)
jejuho 2:b221ba23b37f 33 I2C i2c;
jejuho 2:b221ba23b37f 34
jejuho 2:b221ba23b37f 35 protected:
jejuho 2:b221ba23b37f 36
jejuho 2:b221ba23b37f 37 public:
jejuho 2:b221ba23b37f 38
jejuho 2:b221ba23b37f 39 BMP180(PinName sda, PinName scl) : i2c(sda, scl) {
jejuho 2:b221ba23b37f 40
jejuho 2:b221ba23b37f 41 }
jejuho 2:b221ba23b37f 42
jejuho 2:b221ba23b37f 43
jejuho 2:b221ba23b37f 44
jejuho 2:b221ba23b37f 45 //===================================================================================================================
jejuho 2:b221ba23b37f 46 //====== Set of useful function to access pressure and temperature data
jejuho 2:b221ba23b37f 47 //===================================================================================================================
jejuho 2:b221ba23b37f 48
jejuho 2:b221ba23b37f 49 void writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
jejuho 2:b221ba23b37f 50 {
jejuho 2:b221ba23b37f 51 char data_write[2];
jejuho 2:b221ba23b37f 52 data_write[0] = subAddress;
jejuho 2:b221ba23b37f 53 data_write[1] = data;
jejuho 2:b221ba23b37f 54 i2c.write(address, data_write, 2, 0);
jejuho 2:b221ba23b37f 55 }
jejuho 2:b221ba23b37f 56
jejuho 2:b221ba23b37f 57 char readByte(uint8_t address, uint8_t subAddress)
jejuho 2:b221ba23b37f 58 {
jejuho 2:b221ba23b37f 59 char data[1]; // `data` will store the register data
jejuho 2:b221ba23b37f 60 char data_write[1];
jejuho 2:b221ba23b37f 61 data_write[0] = subAddress;
jejuho 2:b221ba23b37f 62 i2c.write(address, data_write, 1, 1); // no stop
jejuho 2:b221ba23b37f 63 i2c.read(address, data, 1, 0);
jejuho 2:b221ba23b37f 64 return data[0];
jejuho 2:b221ba23b37f 65 }
jejuho 2:b221ba23b37f 66
jejuho 2:b221ba23b37f 67 void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
jejuho 2:b221ba23b37f 68 {
jejuho 2:b221ba23b37f 69 char data[14];
jejuho 2:b221ba23b37f 70 char data_write[1];
jejuho 2:b221ba23b37f 71 data_write[0] = subAddress;
jejuho 2:b221ba23b37f 72 i2c.write(address, data_write, 1, 1); // no stop
jejuho 2:b221ba23b37f 73 i2c.read(address, data, count, 0);
jejuho 2:b221ba23b37f 74 for(int ii = 0; ii < count; ii++) {
jejuho 2:b221ba23b37f 75 dest[ii] = data[ii];
jejuho 2:b221ba23b37f 76 }
jejuho 2:b221ba23b37f 77 }
jejuho 2:b221ba23b37f 78
jejuho 2:b221ba23b37f 79
jejuho 2:b221ba23b37f 80 // Stores all of the BMP180's calibration values into global variables
jejuho 2:b221ba23b37f 81 // Calibration values are required to calculate temp and pressure
jejuho 2:b221ba23b37f 82 // This function should be called at the beginning of the program
jejuho 2:b221ba23b37f 83 // These BMP-180 functions were adapted from Jim Lindblom of SparkFun Electronics
jejuho 2:b221ba23b37f 84 void BMP180Calibration()
jejuho 2:b221ba23b37f 85 {
jejuho 2:b221ba23b37f 86 ac1 = readByte(BMP180_ADDRESS, 0xAA) << 8 | readByte(BMP180_ADDRESS, 0xAB);
jejuho 2:b221ba23b37f 87 ac2 = readByte(BMP180_ADDRESS, 0xAC) << 8 | readByte(BMP180_ADDRESS, 0xAD);
jejuho 2:b221ba23b37f 88 ac3 = readByte(BMP180_ADDRESS, 0xAE) << 8 | readByte(BMP180_ADDRESS, 0xAF);
jejuho 2:b221ba23b37f 89 ac4 = readByte(BMP180_ADDRESS, 0xB0) << 8 | readByte(BMP180_ADDRESS, 0xB1);
jejuho 2:b221ba23b37f 90 ac5 = readByte(BMP180_ADDRESS, 0xB2) << 8 | readByte(BMP180_ADDRESS, 0xB3);
jejuho 2:b221ba23b37f 91 ac6 = readByte(BMP180_ADDRESS, 0xB4) << 8 | readByte(BMP180_ADDRESS, 0xB5);
jejuho 2:b221ba23b37f 92 b1 = readByte(BMP180_ADDRESS, 0xB6) << 8 | readByte(BMP180_ADDRESS, 0xB7);
jejuho 2:b221ba23b37f 93 b2 = readByte(BMP180_ADDRESS, 0xB8) << 8 | readByte(BMP180_ADDRESS, 0xB9);
jejuho 2:b221ba23b37f 94 mb = readByte(BMP180_ADDRESS, 0xBA) << 8 | readByte(BMP180_ADDRESS, 0xBB);
jejuho 2:b221ba23b37f 95 mc = readByte(BMP180_ADDRESS, 0xBC) << 8 | readByte(BMP180_ADDRESS, 0xBD);
jejuho 2:b221ba23b37f 96 md = readByte(BMP180_ADDRESS, 0xBE) << 8 | readByte(BMP180_ADDRESS, 0xBF);
jejuho 2:b221ba23b37f 97 }
jejuho 2:b221ba23b37f 98
jejuho 2:b221ba23b37f 99 // Temperature returned will be in units of 0.1 deg C
jejuho 2:b221ba23b37f 100 int16_t BMP180GetTemperature()
jejuho 2:b221ba23b37f 101 {
jejuho 2:b221ba23b37f 102 int16_t ut = 0;
jejuho 2:b221ba23b37f 103 writeByte(BMP180_ADDRESS, 0xF4, 0x2E); // start temperature measurement
jejuho 2:b221ba23b37f 104 wait(0.005);
jejuho 2:b221ba23b37f 105
jejuho 2:b221ba23b37f 106 uint8_t rawData[2] = {0, 0};
jejuho 2:b221ba23b37f 107 readBytes(BMP180_ADDRESS, 0xF6, 2, &rawData[0]); // read raw temperature measurement
jejuho 2:b221ba23b37f 108 ut = (((int16_t) rawData[0] << 8) | rawData[1]);
jejuho 2:b221ba23b37f 109
jejuho 2:b221ba23b37f 110 long x1, x2;
jejuho 2:b221ba23b37f 111
jejuho 2:b221ba23b37f 112 x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15;
jejuho 2:b221ba23b37f 113 x2 = ((long)mc << 11)/(x1 + md);
jejuho 2:b221ba23b37f 114 b5 = x1 + x2;
jejuho 2:b221ba23b37f 115
jejuho 2:b221ba23b37f 116 return ((b5 + 8)>>4);
jejuho 2:b221ba23b37f 117 }
jejuho 2:b221ba23b37f 118
jejuho 2:b221ba23b37f 119 // Calculate pressure read calibration values
jejuho 2:b221ba23b37f 120 // b5 is also required so BMP180GetTemperature() must be called first.
jejuho 2:b221ba23b37f 121 // Value returned will be pressure in units of Pa.
jejuho 2:b221ba23b37f 122 long BMP180GetPressure()
jejuho 2:b221ba23b37f 123 {
jejuho 2:b221ba23b37f 124 long up = 0;
jejuho 2:b221ba23b37f 125 writeByte(BMP180_ADDRESS, 0xF4, 0x34 | OSS << 6); // Configure pressure measurement for highest resolution
jejuho 2:b221ba23b37f 126 wait((5.0f + 8.0f*3.0f)/1000.0f);
jejuho 2:b221ba23b37f 127 uint8_t rawData[3] = {0, 0, 0};
jejuho 2:b221ba23b37f 128 readBytes(BMP180_ADDRESS, 0xF6, 3, &rawData[0]); // read raw pressure measurement of 19 bits
jejuho 2:b221ba23b37f 129 up = (((long) rawData[0] << 16) | ((long)rawData[1] << 8) | rawData[2]) >> (8 - OSS);
jejuho 2:b221ba23b37f 130
jejuho 2:b221ba23b37f 131 long x1, x2, x3, b3, b6, p;
jejuho 2:b221ba23b37f 132 unsigned long b4, b7;
jejuho 2:b221ba23b37f 133
jejuho 2:b221ba23b37f 134 b6 = b5 - 4000;
jejuho 2:b221ba23b37f 135 // Calculate B3
jejuho 2:b221ba23b37f 136 x1 = (b2 * (b6 * b6)>>12)>>11;
jejuho 2:b221ba23b37f 137 x2 = (ac2 * b6)>>11;
jejuho 2:b221ba23b37f 138 x3 = x1 + x2;
jejuho 2:b221ba23b37f 139 b3 = (((((long)ac1)*4 + x3)<<OSS) + 2)>>2;
jejuho 2:b221ba23b37f 140
jejuho 2:b221ba23b37f 141 // Calculate B4
jejuho 2:b221ba23b37f 142 x1 = (ac3 * b6)>>13;
jejuho 2:b221ba23b37f 143 x2 = (b1 * ((b6 * b6)>>12))>>16;
jejuho 2:b221ba23b37f 144 x3 = ((x1 + x2) + 2)>>2;
jejuho 2:b221ba23b37f 145 b4 = (ac4 * (unsigned long)(x3 + 32768))>>15;
jejuho 2:b221ba23b37f 146
jejuho 2:b221ba23b37f 147 b7 = ((unsigned long)(up - b3) * (50000>>OSS));
jejuho 2:b221ba23b37f 148 if (b7 < 0x80000000)
jejuho 2:b221ba23b37f 149 p = (b7<<1)/b4;
jejuho 2:b221ba23b37f 150 else
jejuho 2:b221ba23b37f 151 p = (b7/b4)<<1;
jejuho 2:b221ba23b37f 152
jejuho 2:b221ba23b37f 153 x1 = (p>>8) * (p>>8);
jejuho 2:b221ba23b37f 154 x1 = (x1 * 3038)>>16;
jejuho 2:b221ba23b37f 155 x2 = (-7357 * p)>>16;
jejuho 2:b221ba23b37f 156 p += (x1 + x2 + 3791)>>4;
jejuho 2:b221ba23b37f 157
jejuho 2:b221ba23b37f 158 return p;
jejuho 2:b221ba23b37f 159 }
jejuho 2:b221ba23b37f 160
jejuho 2:b221ba23b37f 161
jejuho 2:b221ba23b37f 162
jejuho 2:b221ba23b37f 163 };
jejuho 2:b221ba23b37f 164 #endif