joseph adamu / Mbed OS CW_final_thr

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BMP280/BMP280.cpp@1:dc648c5624b9, 2018-01-10 (annotated)

Committer:
joseph_adamu
Date:
Wed Jan 10 09:50:29 2018 +0000
Revision:
1:dc648c5624b9
version for export

Who changed what in which revision?

UserRevisionLine numberNew contents of line
joseph_adamu 1:dc648c5624b9 1 /**
joseph_adamu 1:dc648c5624b9 2 * BMP280 Combined humidity and pressure sensor library
joseph_adamu 1:dc648c5624b9 3 *
joseph_adamu 1:dc648c5624b9 4 * @author Toyomasa Watarai
joseph_adamu 1:dc648c5624b9 5 * @version 1.0
joseph_adamu 1:dc648c5624b9 6 * @date 06-April-2015
joseph_adamu 1:dc648c5624b9 7 *
joseph_adamu 1:dc648c5624b9 8 * bugfixing by charly
joseph_adamu 1:dc648c5624b9 9 *
joseph_adamu 1:dc648c5624b9 10 * Library for "BMP280 temperature, humidity and pressure sensor module" from Switch Science
joseph_adamu 1:dc648c5624b9 11 * https://www.switch-science.com/catalog/2236/
joseph_adamu 1:dc648c5624b9 12 *
joseph_adamu 1:dc648c5624b9 13 * For more information about the BMP280:
joseph_adamu 1:dc648c5624b9 14 * http://ae-bst.resource.bosch.com/media/products/dokumente/BMP280/BST-BMP280_DS001-10.pdf
joseph_adamu 1:dc648c5624b9 15 */
joseph_adamu 1:dc648c5624b9 16
joseph_adamu 1:dc648c5624b9 17 #include "mbed.h"
joseph_adamu 1:dc648c5624b9 18 #include "BMP280.h"
joseph_adamu 1:dc648c5624b9 19
joseph_adamu 1:dc648c5624b9 20 BMP280::BMP280(PinName sda, PinName scl, char slave_adr)
joseph_adamu 1:dc648c5624b9 21 :
joseph_adamu 1:dc648c5624b9 22 i2c_p(new I2C(sda, scl)),
joseph_adamu 1:dc648c5624b9 23 i2c(*i2c_p),
joseph_adamu 1:dc648c5624b9 24 address(slave_adr<<1),
joseph_adamu 1:dc648c5624b9 25 t_fine(0)
joseph_adamu 1:dc648c5624b9 26 {
joseph_adamu 1:dc648c5624b9 27 initialize();
joseph_adamu 1:dc648c5624b9 28 }
joseph_adamu 1:dc648c5624b9 29
joseph_adamu 1:dc648c5624b9 30 BMP280::BMP280(I2C &i2c_obj, char slave_adr)
joseph_adamu 1:dc648c5624b9 31 :
joseph_adamu 1:dc648c5624b9 32 i2c_p(NULL),
joseph_adamu 1:dc648c5624b9 33 i2c(i2c_obj),
joseph_adamu 1:dc648c5624b9 34 address(slave_adr<<1),
joseph_adamu 1:dc648c5624b9 35 t_fine(0)
joseph_adamu 1:dc648c5624b9 36 {
joseph_adamu 1:dc648c5624b9 37 initialize();
joseph_adamu 1:dc648c5624b9 38 }
joseph_adamu 1:dc648c5624b9 39
joseph_adamu 1:dc648c5624b9 40 BMP280::~BMP280()
joseph_adamu 1:dc648c5624b9 41 {
joseph_adamu 1:dc648c5624b9 42 if (NULL != i2c_p)
joseph_adamu 1:dc648c5624b9 43 delete i2c_p;
joseph_adamu 1:dc648c5624b9 44 }
joseph_adamu 1:dc648c5624b9 45
joseph_adamu 1:dc648c5624b9 46 void BMP280::initialize()
joseph_adamu 1:dc648c5624b9 47 {
joseph_adamu 1:dc648c5624b9 48 char cmd[18];
joseph_adamu 1:dc648c5624b9 49
joseph_adamu 1:dc648c5624b9 50 //cmd[0] = 0xf2; // ctrl_hum
joseph_adamu 1:dc648c5624b9 51 //cmd[1] = 0x01; // Humidity oversampling x1
joseph_adamu 1:dc648c5624b9 52 //i2c.write(address, cmd, 2);
joseph_adamu 1:dc648c5624b9 53
joseph_adamu 1:dc648c5624b9 54 cmd[0] = 0xf4; // ctrl_meas
joseph_adamu 1:dc648c5624b9 55 //cmd[1] = 0x27; // Temparature oversampling x1, Pressure oversampling x1, Normal mode
joseph_adamu 1:dc648c5624b9 56 cmd[1] = 0b01010111; // Temparature oversampling x2 010, Pressure oversampling x16 101, Normal mode 11
joseph_adamu 1:dc648c5624b9 57 i2c.write(address, cmd, 2);
joseph_adamu 1:dc648c5624b9 58
joseph_adamu 1:dc648c5624b9 59 cmd[0] = 0xf5; // config
joseph_adamu 1:dc648c5624b9 60 cmd[1] = 0b10111100; // Standby 1000ms, Filter x16
joseph_adamu 1:dc648c5624b9 61 i2c.write(address, cmd, 2);
joseph_adamu 1:dc648c5624b9 62
joseph_adamu 1:dc648c5624b9 63 cmd[0] = 0x88; // read dig_T regs
joseph_adamu 1:dc648c5624b9 64 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 65 i2c.read(address, cmd, 6);
joseph_adamu 1:dc648c5624b9 66
joseph_adamu 1:dc648c5624b9 67 dig_T1 = (cmd[1] << 8) | cmd[0];
joseph_adamu 1:dc648c5624b9 68 dig_T2 = (cmd[3] << 8) | cmd[2];
joseph_adamu 1:dc648c5624b9 69 dig_T3 = (cmd[5] << 8) | cmd[4];
joseph_adamu 1:dc648c5624b9 70
joseph_adamu 1:dc648c5624b9 71 DEBUG_PRINT("dig_T = 0x%x, 0x%x, 0x%x\n\r", dig_T1, dig_T2, dig_T3);
joseph_adamu 1:dc648c5624b9 72 DEBUG_PRINT("dig_T = %d, %d, %d\n\r", dig_T1, dig_T2, dig_T3);
joseph_adamu 1:dc648c5624b9 73
joseph_adamu 1:dc648c5624b9 74 cmd[0] = 0x8E; // read dig_P regs
joseph_adamu 1:dc648c5624b9 75 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 76 i2c.read(address, cmd, 18);
joseph_adamu 1:dc648c5624b9 77
joseph_adamu 1:dc648c5624b9 78 dig_P1 = (cmd[ 1] << 8) | cmd[ 0];
joseph_adamu 1:dc648c5624b9 79 dig_P2 = (cmd[ 3] << 8) | cmd[ 2];
joseph_adamu 1:dc648c5624b9 80 dig_P3 = (cmd[ 5] << 8) | cmd[ 4];
joseph_adamu 1:dc648c5624b9 81 dig_P4 = (cmd[ 7] << 8) | cmd[ 6];
joseph_adamu 1:dc648c5624b9 82 dig_P5 = (cmd[ 9] << 8) | cmd[ 8];
joseph_adamu 1:dc648c5624b9 83 dig_P6 = (cmd[11] << 8) | cmd[10];
joseph_adamu 1:dc648c5624b9 84 dig_P7 = (cmd[13] << 8) | cmd[12];
joseph_adamu 1:dc648c5624b9 85 dig_P8 = (cmd[15] << 8) | cmd[14];
joseph_adamu 1:dc648c5624b9 86 dig_P9 = (cmd[17] << 8) | cmd[16];
joseph_adamu 1:dc648c5624b9 87
joseph_adamu 1:dc648c5624b9 88 DEBUG_PRINT("dig_P = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_P1, dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9);
joseph_adamu 1:dc648c5624b9 89
joseph_adamu 1:dc648c5624b9 90 /* cmd[0] = 0xA1; // read dig_H regs
joseph_adamu 1:dc648c5624b9 91 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 92 i2c.read(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 93 cmd[1] = 0xE1; // read dig_H regs
joseph_adamu 1:dc648c5624b9 94 i2c.write(address, &cmd[1], 1);
joseph_adamu 1:dc648c5624b9 95 i2c.read(address, &cmd[1], 7);
joseph_adamu 1:dc648c5624b9 96
joseph_adamu 1:dc648c5624b9 97 dig_H1 = cmd[0];
joseph_adamu 1:dc648c5624b9 98 dig_H2 = (cmd[2] << 8) | cmd[1];
joseph_adamu 1:dc648c5624b9 99 dig_H3 = cmd[3];
joseph_adamu 1:dc648c5624b9 100 dig_H4 = (cmd[4] << 4) | (cmd[5] & 0x0f);
joseph_adamu 1:dc648c5624b9 101 dig_H5 = (cmd[6] << 4) | ((cmd[5]>>4) & 0x0f);
joseph_adamu 1:dc648c5624b9 102 dig_H6 = cmd[7];
joseph_adamu 1:dc648c5624b9 103
joseph_adamu 1:dc648c5624b9 104 DEBUG_PRINT("dig_H = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_H1, dig_H2, dig_H3, dig_H4, dig_H5, dig_H6);
joseph_adamu 1:dc648c5624b9 105 */
joseph_adamu 1:dc648c5624b9 106 }
joseph_adamu 1:dc648c5624b9 107
joseph_adamu 1:dc648c5624b9 108 float BMP280::getTemperature()
joseph_adamu 1:dc648c5624b9 109 {
joseph_adamu 1:dc648c5624b9 110 int32_t temp_raw;
joseph_adamu 1:dc648c5624b9 111 float tempf;
joseph_adamu 1:dc648c5624b9 112 char cmd[4];
joseph_adamu 1:dc648c5624b9 113
joseph_adamu 1:dc648c5624b9 114 cmd[0] = 0xfa; // temp_msb
joseph_adamu 1:dc648c5624b9 115 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 116 i2c.read(address, &cmd[1], 3);
joseph_adamu 1:dc648c5624b9 117
joseph_adamu 1:dc648c5624b9 118 temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
joseph_adamu 1:dc648c5624b9 119 DEBUG_PRINT("\r\ntemp_raw:%d",temp_raw);
joseph_adamu 1:dc648c5624b9 120
joseph_adamu 1:dc648c5624b9 121 int32_t temp1, temp2,temp;
joseph_adamu 1:dc648c5624b9 122
joseph_adamu 1:dc648c5624b9 123 temp1 =((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11;
joseph_adamu 1:dc648c5624b9 124 temp2 =(((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12) * dig_T3) >> 14;
joseph_adamu 1:dc648c5624b9 125 DEBUG_PRINT(" temp1:%d temp2:%d",temp1, temp2);
joseph_adamu 1:dc648c5624b9 126 t_fine = temp1+temp2;
joseph_adamu 1:dc648c5624b9 127 DEBUG_PRINT(" t_fine:%d",t_fine);
joseph_adamu 1:dc648c5624b9 128 temp = (t_fine * 5 + 128) >> 8;
joseph_adamu 1:dc648c5624b9 129 tempf = (float)temp;
joseph_adamu 1:dc648c5624b9 130 DEBUG_PRINT(" tempf:%f",tempf);
joseph_adamu 1:dc648c5624b9 131
joseph_adamu 1:dc648c5624b9 132 return (tempf/100.0f);
joseph_adamu 1:dc648c5624b9 133 }
joseph_adamu 1:dc648c5624b9 134
joseph_adamu 1:dc648c5624b9 135 float BMP280::getPressure()
joseph_adamu 1:dc648c5624b9 136 {
joseph_adamu 1:dc648c5624b9 137 uint32_t press_raw;
joseph_adamu 1:dc648c5624b9 138 float pressf;
joseph_adamu 1:dc648c5624b9 139 char cmd[4];
joseph_adamu 1:dc648c5624b9 140
joseph_adamu 1:dc648c5624b9 141 cmd[0] = 0xf7; // press_msb
joseph_adamu 1:dc648c5624b9 142 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 143 i2c.read(address, &cmd[1], 3);
joseph_adamu 1:dc648c5624b9 144
joseph_adamu 1:dc648c5624b9 145 press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
joseph_adamu 1:dc648c5624b9 146
joseph_adamu 1:dc648c5624b9 147 int32_t var1, var2;
joseph_adamu 1:dc648c5624b9 148 uint32_t press;
joseph_adamu 1:dc648c5624b9 149
joseph_adamu 1:dc648c5624b9 150 var1 = (t_fine >> 1) - 64000;
joseph_adamu 1:dc648c5624b9 151 var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * dig_P6;
joseph_adamu 1:dc648c5624b9 152 var2 = var2 + ((var1 * dig_P5) << 1);
joseph_adamu 1:dc648c5624b9 153 var2 = (var2 >> 2) + (dig_P4 << 16);
joseph_adamu 1:dc648c5624b9 154 var1 = (((dig_P3 * (((var1 >> 2)*(var1 >> 2)) >> 13)) >> 3) + ((dig_P2 * var1) >> 1)) >> 18;
joseph_adamu 1:dc648c5624b9 155 var1 = ((32768 + var1) * dig_P1) >> 15;
joseph_adamu 1:dc648c5624b9 156 if (var1 == 0) {
joseph_adamu 1:dc648c5624b9 157 return 0;
joseph_adamu 1:dc648c5624b9 158 }
joseph_adamu 1:dc648c5624b9 159 press = (((1048576 - press_raw) - (var2 >> 12))) * 3125;
joseph_adamu 1:dc648c5624b9 160 if(press < 0x80000000) {
joseph_adamu 1:dc648c5624b9 161 press = (press << 1) / var1;
joseph_adamu 1:dc648c5624b9 162 } else {
joseph_adamu 1:dc648c5624b9 163 press = (press / var1) * 2;
joseph_adamu 1:dc648c5624b9 164 }
joseph_adamu 1:dc648c5624b9 165 var1 = ((int32_t)dig_P9 * ((int32_t)(((press >> 3) * (press >> 3)) >> 13))) >> 12;
joseph_adamu 1:dc648c5624b9 166 var2 = (((int32_t)(press >> 2)) * (int32_t)dig_P8) >> 13;
joseph_adamu 1:dc648c5624b9 167 press = (press + ((var1 + var2 + dig_P7) >> 4));
joseph_adamu 1:dc648c5624b9 168
joseph_adamu 1:dc648c5624b9 169 pressf = (float)press;
joseph_adamu 1:dc648c5624b9 170 return (pressf/100.0f);
joseph_adamu 1:dc648c5624b9 171 }