2016_mbed_iot_project / Mbed 2 deprecated myiot

student project

Dependencies:   mbed

Fork of myiot by joseph chen

include/BME280.cpp@4:07e0a94f29da, 2016-06-22 (annotated)

Committer:
hank51017
Date:
Wed Jun 22 08:12:27 2016 +0000
Revision:
4:07e0a94f29da
OLED+BMP280

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hank51017 4:07e0a94f29da 1 /**
hank51017 4:07e0a94f29da 2 * BME280 Combined humidity and pressure sensor library
hank51017 4:07e0a94f29da 3 *
hank51017 4:07e0a94f29da 4 * @author Toyomasa Watarai
hank51017 4:07e0a94f29da 5 * @version 1.0
hank51017 4:07e0a94f29da 6 * @date 06-April-2015
hank51017 4:07e0a94f29da 7 *
hank51017 4:07e0a94f29da 8 * Library for "BME280 temperature, humidity and pressure sensor module" from Switch Science
hank51017 4:07e0a94f29da 9 * https://www.switch-science.com/catalog/2236/
hank51017 4:07e0a94f29da 10 *
hank51017 4:07e0a94f29da 11 * For more information about the BME280:
hank51017 4:07e0a94f29da 12 * http://ae-bst.resource.bosch.com/media/products/dokumente/bme280/BST-BME280_DS001-10.pdf
hank51017 4:07e0a94f29da 13 */
hank51017 4:07e0a94f29da 14
hank51017 4:07e0a94f29da 15 #include "mbed.h"
hank51017 4:07e0a94f29da 16 #include "BME280.h"
hank51017 4:07e0a94f29da 17
hank51017 4:07e0a94f29da 18 BME280::BME280(PinName sda, PinName scl, char slave_adr)
hank51017 4:07e0a94f29da 19 :
hank51017 4:07e0a94f29da 20 i2c_p(new I2C(sda, scl)),
hank51017 4:07e0a94f29da 21 i2c(*i2c_p),
hank51017 4:07e0a94f29da 22 address(slave_adr),
hank51017 4:07e0a94f29da 23 t_fine(0)
hank51017 4:07e0a94f29da 24 {
hank51017 4:07e0a94f29da 25 initialize();
hank51017 4:07e0a94f29da 26 }
hank51017 4:07e0a94f29da 27
hank51017 4:07e0a94f29da 28 BME280::BME280(I2C &i2c_obj, char slave_adr)
hank51017 4:07e0a94f29da 29 :
hank51017 4:07e0a94f29da 30 i2c_p(NULL),
hank51017 4:07e0a94f29da 31 i2c(i2c_obj),
hank51017 4:07e0a94f29da 32 address(slave_adr),
hank51017 4:07e0a94f29da 33 t_fine(0)
hank51017 4:07e0a94f29da 34 {
hank51017 4:07e0a94f29da 35 initialize();
hank51017 4:07e0a94f29da 36 }
hank51017 4:07e0a94f29da 37
hank51017 4:07e0a94f29da 38 BME280::~BME280()
hank51017 4:07e0a94f29da 39 {
hank51017 4:07e0a94f29da 40 if (NULL != i2c_p)
hank51017 4:07e0a94f29da 41 delete i2c_p;
hank51017 4:07e0a94f29da 42 }
hank51017 4:07e0a94f29da 43
hank51017 4:07e0a94f29da 44 void BME280::initialize()
hank51017 4:07e0a94f29da 45 {
hank51017 4:07e0a94f29da 46 char cmd[18];
hank51017 4:07e0a94f29da 47
hank51017 4:07e0a94f29da 48 cmd[0] = 0xf2; // ctrl_hum
hank51017 4:07e0a94f29da 49 cmd[1] = 0x01; // Humidity oversampling x1
hank51017 4:07e0a94f29da 50 i2c.write(address, cmd, 2);
hank51017 4:07e0a94f29da 51
hank51017 4:07e0a94f29da 52 cmd[0] = 0xf4; // ctrl_meas
hank51017 4:07e0a94f29da 53 cmd[1] = 0x27; // Temparature oversampling x1, Pressure oversampling x1, Normal mode
hank51017 4:07e0a94f29da 54 i2c.write(address, cmd, 2);
hank51017 4:07e0a94f29da 55
hank51017 4:07e0a94f29da 56 cmd[0] = 0xf5; // config
hank51017 4:07e0a94f29da 57 cmd[1] = 0xa0; // Standby 1000ms, Filter off
hank51017 4:07e0a94f29da 58 i2c.write(address, cmd, 2);
hank51017 4:07e0a94f29da 59
hank51017 4:07e0a94f29da 60 cmd[0] = 0x88; // read dig_T regs
hank51017 4:07e0a94f29da 61 i2c.write(address, cmd, 1);
hank51017 4:07e0a94f29da 62 i2c.read(address, cmd, 6);
hank51017 4:07e0a94f29da 63
hank51017 4:07e0a94f29da 64 dig_T1 = (cmd[1] << 8) | cmd[0];
hank51017 4:07e0a94f29da 65 dig_T2 = (cmd[3] << 8) | cmd[2];
hank51017 4:07e0a94f29da 66 dig_T3 = (cmd[5] << 8) | cmd[4];
hank51017 4:07e0a94f29da 67
hank51017 4:07e0a94f29da 68 DEBUG_PRINT("dig_T = 0x%x, 0x%x, 0x%x\n", dig_T1, dig_T2, dig_T3);
hank51017 4:07e0a94f29da 69
hank51017 4:07e0a94f29da 70 cmd[0] = 0x8E; // read dig_P regs
hank51017 4:07e0a94f29da 71 i2c.write(address, cmd, 1);
hank51017 4:07e0a94f29da 72 i2c.read(address, cmd, 18);
hank51017 4:07e0a94f29da 73
hank51017 4:07e0a94f29da 74 dig_P1 = (cmd[ 1] << 8) | cmd[ 0];
hank51017 4:07e0a94f29da 75 dig_P2 = (cmd[ 3] << 8) | cmd[ 2];
hank51017 4:07e0a94f29da 76 dig_P3 = (cmd[ 5] << 8) | cmd[ 4];
hank51017 4:07e0a94f29da 77 dig_P4 = (cmd[ 7] << 8) | cmd[ 6];
hank51017 4:07e0a94f29da 78 dig_P5 = (cmd[ 9] << 8) | cmd[ 8];
hank51017 4:07e0a94f29da 79 dig_P6 = (cmd[11] << 8) | cmd[10];
hank51017 4:07e0a94f29da 80 dig_P7 = (cmd[13] << 8) | cmd[12];
hank51017 4:07e0a94f29da 81 dig_P8 = (cmd[15] << 8) | cmd[14];
hank51017 4:07e0a94f29da 82 dig_P9 = (cmd[17] << 8) | cmd[16];
hank51017 4:07e0a94f29da 83
hank51017 4:07e0a94f29da 84 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);
hank51017 4:07e0a94f29da 85
hank51017 4:07e0a94f29da 86 cmd[0] = 0xA1; // read dig_H regs
hank51017 4:07e0a94f29da 87 i2c.write(address, cmd, 1);
hank51017 4:07e0a94f29da 88 i2c.read(address, cmd, 1);
hank51017 4:07e0a94f29da 89 cmd[1] = 0xE1; // read dig_H regs
hank51017 4:07e0a94f29da 90 i2c.write(address, &cmd[1], 1);
hank51017 4:07e0a94f29da 91 i2c.read(address, &cmd[1], 7);
hank51017 4:07e0a94f29da 92
hank51017 4:07e0a94f29da 93 dig_H1 = cmd[0];
hank51017 4:07e0a94f29da 94 dig_H2 = (cmd[2] << 8) | cmd[1];
hank51017 4:07e0a94f29da 95 dig_H3 = cmd[3];
hank51017 4:07e0a94f29da 96 dig_H4 = (cmd[4] << 4) | (cmd[5] & 0x0f);
hank51017 4:07e0a94f29da 97 dig_H5 = (cmd[6] << 4) | ((cmd[5]>>4) & 0x0f);
hank51017 4:07e0a94f29da 98 dig_H6 = cmd[7];
hank51017 4:07e0a94f29da 99
hank51017 4:07e0a94f29da 100 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);
hank51017 4:07e0a94f29da 101 }
hank51017 4:07e0a94f29da 102
hank51017 4:07e0a94f29da 103 float BME280::getTemperature()
hank51017 4:07e0a94f29da 104 {
hank51017 4:07e0a94f29da 105 uint32_t temp_raw;
hank51017 4:07e0a94f29da 106 float tempf;
hank51017 4:07e0a94f29da 107 char cmd[4];
hank51017 4:07e0a94f29da 108
hank51017 4:07e0a94f29da 109 cmd[0] = 0xfa; // temp_msb
hank51017 4:07e0a94f29da 110 i2c.write(address, cmd, 1);
hank51017 4:07e0a94f29da 111 i2c.read(address, &cmd[1], 3);
hank51017 4:07e0a94f29da 112
hank51017 4:07e0a94f29da 113 temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
hank51017 4:07e0a94f29da 114
hank51017 4:07e0a94f29da 115 int32_t temp;
hank51017 4:07e0a94f29da 116
hank51017 4:07e0a94f29da 117 temp =
hank51017 4:07e0a94f29da 118 (((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11) +
hank51017 4:07e0a94f29da 119 ((((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12) * dig_T3) >> 14);
hank51017 4:07e0a94f29da 120
hank51017 4:07e0a94f29da 121 t_fine = temp;
hank51017 4:07e0a94f29da 122 temp = (temp * 5 + 128) >> 8;
hank51017 4:07e0a94f29da 123 tempf = (float)temp;
hank51017 4:07e0a94f29da 124
hank51017 4:07e0a94f29da 125 return (((tempf/100.0f)-32)*5/9);
hank51017 4:07e0a94f29da 126 }
hank51017 4:07e0a94f29da 127
hank51017 4:07e0a94f29da 128 float BME280::getPressure()
hank51017 4:07e0a94f29da 129 {
hank51017 4:07e0a94f29da 130 uint32_t press_raw;
hank51017 4:07e0a94f29da 131 float pressf;
hank51017 4:07e0a94f29da 132 char cmd[4];
hank51017 4:07e0a94f29da 133 int i;
hank51017 4:07e0a94f29da 134
hank51017 4:07e0a94f29da 135 cmd[0] = 0xf7; // press_msb
hank51017 4:07e0a94f29da 136 i2c.write(address, cmd, 1);
hank51017 4:07e0a94f29da 137 i2c.read(address, &cmd[1], 3);
hank51017 4:07e0a94f29da 138
hank51017 4:07e0a94f29da 139 for(i=0;i<4;i++)
hank51017 4:07e0a94f29da 140 printf("cmdp[%d] = %x\r\n", i,cmd[i]);
hank51017 4:07e0a94f29da 141
hank51017 4:07e0a94f29da 142 press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
hank51017 4:07e0a94f29da 143
hank51017 4:07e0a94f29da 144 int32_t var1, var2;
hank51017 4:07e0a94f29da 145 uint32_t press;
hank51017 4:07e0a94f29da 146
hank51017 4:07e0a94f29da 147 var1 = (t_fine >> 1) - 64000;
hank51017 4:07e0a94f29da 148 var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * dig_P6;
hank51017 4:07e0a94f29da 149 var2 = var2 + ((var1 * dig_P5) << 1);
hank51017 4:07e0a94f29da 150 var2 = (var2 >> 2) + (dig_P4 << 16);
hank51017 4:07e0a94f29da 151 var1 = (((dig_P3 * (((var1 >> 2)*(var1 >> 2)) >> 13)) >> 3) + ((dig_P2 * var1) >> 1)) >> 18;
hank51017 4:07e0a94f29da 152 var1 = ((32768 + var1) * dig_P1) >> 15;
hank51017 4:07e0a94f29da 153 if (var1 == 0) {
hank51017 4:07e0a94f29da 154 return 0;
hank51017 4:07e0a94f29da 155 }
hank51017 4:07e0a94f29da 156 press = (((1048576 - press_raw) - (var2 >> 12))) * 3125;
hank51017 4:07e0a94f29da 157 if(press < 0x80000000) {
hank51017 4:07e0a94f29da 158 press = (press << 1) / var1;
hank51017 4:07e0a94f29da 159 } else {
hank51017 4:07e0a94f29da 160 press = (press / var1) * 2;
hank51017 4:07e0a94f29da 161 }
hank51017 4:07e0a94f29da 162 var1 = ((int32_t)dig_P9 * ((int32_t)(((press >> 3) * (press >> 3)) >> 13))) >> 12;
hank51017 4:07e0a94f29da 163 var2 = (((int32_t)(press >> 2)) * (int32_t)dig_P8) >> 13;
hank51017 4:07e0a94f29da 164 press = (press + ((var1 + var2 + dig_P7) >> 4));
hank51017 4:07e0a94f29da 165
hank51017 4:07e0a94f29da 166 pressf = (float)press;
hank51017 4:07e0a94f29da 167 return (pressf/100.0f);
hank51017 4:07e0a94f29da 168 }
hank51017 4:07e0a94f29da 169
hank51017 4:07e0a94f29da 170 float BME280::getHumidity()
hank51017 4:07e0a94f29da 171 {
hank51017 4:07e0a94f29da 172 uint32_t hum_raw;
hank51017 4:07e0a94f29da 173 float humf;
hank51017 4:07e0a94f29da 174 char cmd[16];
hank51017 4:07e0a94f29da 175 int i;
hank51017 4:07e0a94f29da 176
hank51017 4:07e0a94f29da 177
hank51017 4:07e0a94f29da 178 cmd[0] = 0xfd; // hum_msb
hank51017 4:07e0a94f29da 179 i2c.write(address, cmd, 1);
hank51017 4:07e0a94f29da 180 i2c.read(address, &cmd[1], 2);
hank51017 4:07e0a94f29da 181
hank51017 4:07e0a94f29da 182
hank51017 4:07e0a94f29da 183
hank51017 4:07e0a94f29da 184 printf("address2 = %x\r\n", address);
hank51017 4:07e0a94f29da 185 for(i=0;i<16;i++)
hank51017 4:07e0a94f29da 186 printf("cmd[%d] = %x\r\n", i,cmd[i]);
hank51017 4:07e0a94f29da 187
hank51017 4:07e0a94f29da 188 hum_raw = (cmd[1] << 8) | cmd[2];
hank51017 4:07e0a94f29da 189
hank51017 4:07e0a94f29da 190 printf("hum_raw = %x\r\n", hum_raw);
hank51017 4:07e0a94f29da 191
hank51017 4:07e0a94f29da 192 int32_t v_x1;
hank51017 4:07e0a94f29da 193
hank51017 4:07e0a94f29da 194 v_x1 = t_fine - 76800;
hank51017 4:07e0a94f29da 195
hank51017 4:07e0a94f29da 196 v_x1 = (((((hum_raw << 14) -(((int32_t)dig_H4) << 20) - (((int32_t)dig_H5) * v_x1)) +
hank51017 4:07e0a94f29da 197 ((int32_t)16384)) >> 15) * (((((((v_x1 * (int32_t)dig_H6) >> 10) *
hank51017 4:07e0a94f29da 198 (((v_x1 * ((int32_t)dig_H3)) >> 11) + 32768)) >> 10) + (int32_t)2097152) *
hank51017 4:07e0a94f29da 199 (int32_t)dig_H2 + 8192) >> 14));
hank51017 4:07e0a94f29da 200
hank51017 4:07e0a94f29da 201 v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * (int32_t)dig_H1) >> 4));
hank51017 4:07e0a94f29da 202 printf("v_x2 = %d\r\n", v_x1);
hank51017 4:07e0a94f29da 203 v_x1 = (v_x1 < 0 ? 0 : v_x1);
hank51017 4:07e0a94f29da 204 printf("v_x2 = %d\r\n", v_x1);
hank51017 4:07e0a94f29da 205 v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
hank51017 4:07e0a94f29da 206
hank51017 4:07e0a94f29da 207
hank51017 4:07e0a94f29da 208
hank51017 4:07e0a94f29da 209 humf = (int32_t)(v_x1 >> 12);
hank51017 4:07e0a94f29da 210
hank51017 4:07e0a94f29da 211 return (humf/1024.0f);
hank51017 4:07e0a94f29da 212
hank51017 4:07e0a94f29da 213 }