joseph adamu / Mbed OS CW_final_thr

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BME280/BME280.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 ******************************************************************************
joseph_adamu 1:dc648c5624b9 3 * @file BME280.cpp
joseph_adamu 1:dc648c5624b9 4 * @author Toyomasa Watarai
joseph_adamu 1:dc648c5624b9 5 * @version V1.0.0
joseph_adamu 1:dc648c5624b9 6 * @date 11 March 2017
joseph_adamu 1:dc648c5624b9 7 * @brief BME280 class implementation
joseph_adamu 1:dc648c5624b9 8 ******************************************************************************
joseph_adamu 1:dc648c5624b9 9 * @attention
joseph_adamu 1:dc648c5624b9 10 *
joseph_adamu 1:dc648c5624b9 11 * Permission is hereby granted, free of charge, to any person obtaining a copy
joseph_adamu 1:dc648c5624b9 12 * of this software and associated documentation files (the "Software"), to deal
joseph_adamu 1:dc648c5624b9 13 * in the Software without restriction, including without limitation the rights
joseph_adamu 1:dc648c5624b9 14 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
joseph_adamu 1:dc648c5624b9 15 * copies of the Software, and to permit persons to whom the Software is
joseph_adamu 1:dc648c5624b9 16 * furnished to do so, subject to the following conditions:
joseph_adamu 1:dc648c5624b9 17 *
joseph_adamu 1:dc648c5624b9 18 * The above copyright notice and this permission notice shall be included in
joseph_adamu 1:dc648c5624b9 19 * all copies or substantial portions of the Software.
joseph_adamu 1:dc648c5624b9 20 *
joseph_adamu 1:dc648c5624b9 21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
joseph_adamu 1:dc648c5624b9 22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
joseph_adamu 1:dc648c5624b9 23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
joseph_adamu 1:dc648c5624b9 24 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
joseph_adamu 1:dc648c5624b9 25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
joseph_adamu 1:dc648c5624b9 26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
joseph_adamu 1:dc648c5624b9 27 * THE SOFTWARE.
joseph_adamu 1:dc648c5624b9 28 */
joseph_adamu 1:dc648c5624b9 29
joseph_adamu 1:dc648c5624b9 30 #include "mbed.h"
joseph_adamu 1:dc648c5624b9 31 #include "BME280.h"
joseph_adamu 1:dc648c5624b9 32
joseph_adamu 1:dc648c5624b9 33 BME280::BME280(PinName sda, PinName scl, char slave_adr)
joseph_adamu 1:dc648c5624b9 34 :
joseph_adamu 1:dc648c5624b9 35 i2c_p(new I2C(sda, scl)),
joseph_adamu 1:dc648c5624b9 36 i2c(*i2c_p),
joseph_adamu 1:dc648c5624b9 37 address(slave_adr),
joseph_adamu 1:dc648c5624b9 38 t_fine(0)
joseph_adamu 1:dc648c5624b9 39 {
joseph_adamu 1:dc648c5624b9 40 initialize();
joseph_adamu 1:dc648c5624b9 41 }
joseph_adamu 1:dc648c5624b9 42
joseph_adamu 1:dc648c5624b9 43 BME280::BME280(I2C &i2c_obj, char slave_adr)
joseph_adamu 1:dc648c5624b9 44 :
joseph_adamu 1:dc648c5624b9 45 i2c_p(NULL),
joseph_adamu 1:dc648c5624b9 46 i2c(i2c_obj),
joseph_adamu 1:dc648c5624b9 47 address(slave_adr),
joseph_adamu 1:dc648c5624b9 48 t_fine(0)
joseph_adamu 1:dc648c5624b9 49 {
joseph_adamu 1:dc648c5624b9 50 initialize();
joseph_adamu 1:dc648c5624b9 51 }
joseph_adamu 1:dc648c5624b9 52
joseph_adamu 1:dc648c5624b9 53 BME280::~BME280()
joseph_adamu 1:dc648c5624b9 54 {
joseph_adamu 1:dc648c5624b9 55 if (NULL != i2c_p)
joseph_adamu 1:dc648c5624b9 56 delete i2c_p;
joseph_adamu 1:dc648c5624b9 57 }
joseph_adamu 1:dc648c5624b9 58
joseph_adamu 1:dc648c5624b9 59 void BME280::initialize()
joseph_adamu 1:dc648c5624b9 60 {
joseph_adamu 1:dc648c5624b9 61 char cmd[18];
joseph_adamu 1:dc648c5624b9 62
joseph_adamu 1:dc648c5624b9 63 cmd[0] = 0xf2; // ctrl_hum
joseph_adamu 1:dc648c5624b9 64 cmd[1] = 0x01; // Humidity oversampling x1
joseph_adamu 1:dc648c5624b9 65 i2c.write(address, cmd, 2);
joseph_adamu 1:dc648c5624b9 66
joseph_adamu 1:dc648c5624b9 67 cmd[0] = 0xf4; // ctrl_meas
joseph_adamu 1:dc648c5624b9 68 cmd[1] = 0x27; // Temparature oversampling x1, Pressure oversampling x1, Normal mode
joseph_adamu 1:dc648c5624b9 69 i2c.write(address, cmd, 2);
joseph_adamu 1:dc648c5624b9 70
joseph_adamu 1:dc648c5624b9 71 cmd[0] = 0xf5; // config
joseph_adamu 1:dc648c5624b9 72 cmd[1] = 0xa0; // Standby 1000ms, Filter off
joseph_adamu 1:dc648c5624b9 73 i2c.write(address, cmd, 2);
joseph_adamu 1:dc648c5624b9 74
joseph_adamu 1:dc648c5624b9 75 cmd[0] = 0x88; // read dig_T regs
joseph_adamu 1:dc648c5624b9 76 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 77 i2c.read(address, cmd, 6);
joseph_adamu 1:dc648c5624b9 78
joseph_adamu 1:dc648c5624b9 79 dig_T1 = (cmd[1] << 8) | cmd[0];
joseph_adamu 1:dc648c5624b9 80 dig_T2 = (cmd[3] << 8) | cmd[2];
joseph_adamu 1:dc648c5624b9 81 dig_T3 = (cmd[5] << 8) | cmd[4];
joseph_adamu 1:dc648c5624b9 82
joseph_adamu 1:dc648c5624b9 83 DEBUG_PRINT("dig_T = 0x%x, 0x%x, 0x%x\n", dig_T1, dig_T2, dig_T3);
joseph_adamu 1:dc648c5624b9 84
joseph_adamu 1:dc648c5624b9 85 cmd[0] = 0x8E; // read dig_P regs
joseph_adamu 1:dc648c5624b9 86 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 87 i2c.read(address, cmd, 18);
joseph_adamu 1:dc648c5624b9 88
joseph_adamu 1:dc648c5624b9 89 dig_P1 = (cmd[ 1] << 8) | cmd[ 0];
joseph_adamu 1:dc648c5624b9 90 dig_P2 = (cmd[ 3] << 8) | cmd[ 2];
joseph_adamu 1:dc648c5624b9 91 dig_P3 = (cmd[ 5] << 8) | cmd[ 4];
joseph_adamu 1:dc648c5624b9 92 dig_P4 = (cmd[ 7] << 8) | cmd[ 6];
joseph_adamu 1:dc648c5624b9 93 dig_P5 = (cmd[ 9] << 8) | cmd[ 8];
joseph_adamu 1:dc648c5624b9 94 dig_P6 = (cmd[11] << 8) | cmd[10];
joseph_adamu 1:dc648c5624b9 95 dig_P7 = (cmd[13] << 8) | cmd[12];
joseph_adamu 1:dc648c5624b9 96 dig_P8 = (cmd[15] << 8) | cmd[14];
joseph_adamu 1:dc648c5624b9 97 dig_P9 = (cmd[17] << 8) | cmd[16];
joseph_adamu 1:dc648c5624b9 98
joseph_adamu 1:dc648c5624b9 99 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 100
joseph_adamu 1:dc648c5624b9 101 cmd[0] = 0xA1; // read dig_H regs
joseph_adamu 1:dc648c5624b9 102 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 103 i2c.read(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 104 cmd[1] = 0xE1; // read dig_H regs
joseph_adamu 1:dc648c5624b9 105 i2c.write(address, &cmd[1], 1);
joseph_adamu 1:dc648c5624b9 106 i2c.read(address, &cmd[1], 7);
joseph_adamu 1:dc648c5624b9 107
joseph_adamu 1:dc648c5624b9 108 dig_H1 = cmd[0];
joseph_adamu 1:dc648c5624b9 109 dig_H2 = (cmd[2] << 8) | cmd[1];
joseph_adamu 1:dc648c5624b9 110 dig_H3 = cmd[3];
joseph_adamu 1:dc648c5624b9 111 dig_H4 = (cmd[4] << 4) | (cmd[5] & 0x0f);
joseph_adamu 1:dc648c5624b9 112 dig_H5 = (cmd[6] << 4) | ((cmd[5]>>4) & 0x0f);
joseph_adamu 1:dc648c5624b9 113 dig_H6 = cmd[7];
joseph_adamu 1:dc648c5624b9 114
joseph_adamu 1:dc648c5624b9 115 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 116 }
joseph_adamu 1:dc648c5624b9 117
joseph_adamu 1:dc648c5624b9 118 float BME280::getTemperature()
joseph_adamu 1:dc648c5624b9 119 {
joseph_adamu 1:dc648c5624b9 120 uint32_t temp_raw;
joseph_adamu 1:dc648c5624b9 121 float tempf;
joseph_adamu 1:dc648c5624b9 122 char cmd[4];
joseph_adamu 1:dc648c5624b9 123
joseph_adamu 1:dc648c5624b9 124 cmd[0] = 0xfa; // temp_msb
joseph_adamu 1:dc648c5624b9 125 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 126 i2c.read(address, &cmd[1], 3);
joseph_adamu 1:dc648c5624b9 127
joseph_adamu 1:dc648c5624b9 128 temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
joseph_adamu 1:dc648c5624b9 129
joseph_adamu 1:dc648c5624b9 130 int32_t temp;
joseph_adamu 1:dc648c5624b9 131
joseph_adamu 1:dc648c5624b9 132 temp =
joseph_adamu 1:dc648c5624b9 133 (((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11) +
joseph_adamu 1:dc648c5624b9 134 ((((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12) * dig_T3) >> 14);
joseph_adamu 1:dc648c5624b9 135
joseph_adamu 1:dc648c5624b9 136 t_fine = temp;
joseph_adamu 1:dc648c5624b9 137 temp = (temp * 5 + 128) >> 8;
joseph_adamu 1:dc648c5624b9 138 tempf = (float)temp;
joseph_adamu 1:dc648c5624b9 139
joseph_adamu 1:dc648c5624b9 140 return (tempf/100.0f);
joseph_adamu 1:dc648c5624b9 141 }
joseph_adamu 1:dc648c5624b9 142
joseph_adamu 1:dc648c5624b9 143 float BME280::getPressure()
joseph_adamu 1:dc648c5624b9 144 {
joseph_adamu 1:dc648c5624b9 145 uint32_t press_raw;
joseph_adamu 1:dc648c5624b9 146 float pressf;
joseph_adamu 1:dc648c5624b9 147 char cmd[4];
joseph_adamu 1:dc648c5624b9 148
joseph_adamu 1:dc648c5624b9 149 cmd[0] = 0xf7; // press_msb
joseph_adamu 1:dc648c5624b9 150 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 151 i2c.read(address, &cmd[1], 3);
joseph_adamu 1:dc648c5624b9 152
joseph_adamu 1:dc648c5624b9 153 press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
joseph_adamu 1:dc648c5624b9 154
joseph_adamu 1:dc648c5624b9 155 int32_t var1, var2;
joseph_adamu 1:dc648c5624b9 156 uint32_t press;
joseph_adamu 1:dc648c5624b9 157
joseph_adamu 1:dc648c5624b9 158 var1 = (t_fine >> 1) - 64000;
joseph_adamu 1:dc648c5624b9 159 var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * dig_P6;
joseph_adamu 1:dc648c5624b9 160 var2 = var2 + ((var1 * dig_P5) << 1);
joseph_adamu 1:dc648c5624b9 161 var2 = (var2 >> 2) + (dig_P4 << 16);
joseph_adamu 1:dc648c5624b9 162 var1 = (((dig_P3 * (((var1 >> 2)*(var1 >> 2)) >> 13)) >> 3) + ((dig_P2 * var1) >> 1)) >> 18;
joseph_adamu 1:dc648c5624b9 163 var1 = ((32768 + var1) * dig_P1) >> 15;
joseph_adamu 1:dc648c5624b9 164 if (var1 == 0) {
joseph_adamu 1:dc648c5624b9 165 return 0;
joseph_adamu 1:dc648c5624b9 166 }
joseph_adamu 1:dc648c5624b9 167 press = (((1048576 - press_raw) - (var2 >> 12))) * 3125;
joseph_adamu 1:dc648c5624b9 168 if(press < 0x80000000) {
joseph_adamu 1:dc648c5624b9 169 press = (press << 1) / var1;
joseph_adamu 1:dc648c5624b9 170 } else {
joseph_adamu 1:dc648c5624b9 171 press = (press / var1) * 2;
joseph_adamu 1:dc648c5624b9 172 }
joseph_adamu 1:dc648c5624b9 173 var1 = ((int32_t)dig_P9 * ((int32_t)(((press >> 3) * (press >> 3)) >> 13))) >> 12;
joseph_adamu 1:dc648c5624b9 174 var2 = (((int32_t)(press >> 2)) * (int32_t)dig_P8) >> 13;
joseph_adamu 1:dc648c5624b9 175 press = (press + ((var1 + var2 + dig_P7) >> 4));
joseph_adamu 1:dc648c5624b9 176
joseph_adamu 1:dc648c5624b9 177 pressf = (float)press;
joseph_adamu 1:dc648c5624b9 178 return (pressf/100.0f);
joseph_adamu 1:dc648c5624b9 179 }
joseph_adamu 1:dc648c5624b9 180
joseph_adamu 1:dc648c5624b9 181 float BME280::getHumidity()
joseph_adamu 1:dc648c5624b9 182 {
joseph_adamu 1:dc648c5624b9 183 uint32_t hum_raw;
joseph_adamu 1:dc648c5624b9 184 float humf;
joseph_adamu 1:dc648c5624b9 185 char cmd[4];
joseph_adamu 1:dc648c5624b9 186
joseph_adamu 1:dc648c5624b9 187 cmd[0] = 0xfd; // hum_msb
joseph_adamu 1:dc648c5624b9 188 i2c.write(address, cmd, 1);
joseph_adamu 1:dc648c5624b9 189 i2c.read(address, &cmd[1], 2);
joseph_adamu 1:dc648c5624b9 190
joseph_adamu 1:dc648c5624b9 191 hum_raw = (cmd[1] << 8) | cmd[2];
joseph_adamu 1:dc648c5624b9 192
joseph_adamu 1:dc648c5624b9 193 int32_t v_x1;
joseph_adamu 1:dc648c5624b9 194
joseph_adamu 1:dc648c5624b9 195 v_x1 = t_fine - 76800;
joseph_adamu 1:dc648c5624b9 196 v_x1 = (((((hum_raw << 14) -(((int32_t)dig_H4) << 20) - (((int32_t)dig_H5) * v_x1)) +
joseph_adamu 1:dc648c5624b9 197 ((int32_t)16384)) >> 15) * (((((((v_x1 * (int32_t)dig_H6) >> 10) *
joseph_adamu 1:dc648c5624b9 198 (((v_x1 * ((int32_t)dig_H3)) >> 11) + 32768)) >> 10) + 2097152) *
joseph_adamu 1:dc648c5624b9 199 (int32_t)dig_H2 + 8192) >> 14));
joseph_adamu 1:dc648c5624b9 200 v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * (int32_t)dig_H1) >> 4));
joseph_adamu 1:dc648c5624b9 201 v_x1 = (v_x1 < 0 ? 0 : v_x1);
joseph_adamu 1:dc648c5624b9 202 v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
joseph_adamu 1:dc648c5624b9 203
joseph_adamu 1:dc648c5624b9 204 humf = (float)(v_x1 >> 12);
joseph_adamu 1:dc648c5624b9 205
joseph_adamu 1:dc648c5624b9 206 return (humf/1024.0f);
joseph_adamu 1:dc648c5624b9 207 }