BME280 library
BME280.cpp@1:0054d4a28927, 2016-08-03 (annotated)
- Committer:
- yasuyuki
- Date:
- Wed Aug 03 14:28:32 2016 +0000
- Revision:
- 1:0054d4a28927
- Parent:
- 0:b32d0acc420d
added wait
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
yasuyuki | 0:b32d0acc420d | 1 | //********************** |
yasuyuki | 0:b32d0acc420d | 2 | // BME280.cpp for mbed |
yasuyuki | 0:b32d0acc420d | 3 | // |
yasuyuki | 0:b32d0acc420d | 4 | // BME280 bme280(P0_5,P0_4); |
yasuyuki | 0:b32d0acc420d | 5 | // or |
yasuyuki | 0:b32d0acc420d | 6 | // I2C i2c(P0_5,P0_4); |
yasuyuki | 0:b32d0acc420d | 7 | // BME280 bme280(i2c); |
yasuyuki | 0:b32d0acc420d | 8 | // |
yasuyuki | 0:b32d0acc420d | 9 | // (C)Copyright 2015 All rights reserved by Y.Onodera |
yasuyuki | 0:b32d0acc420d | 10 | // http://einstlab.web.fc2.com |
yasuyuki | 0:b32d0acc420d | 11 | //********************** |
yasuyuki | 0:b32d0acc420d | 12 | |
yasuyuki | 0:b32d0acc420d | 13 | #include "mbed.h" |
yasuyuki | 0:b32d0acc420d | 14 | #include "BME280.h" |
yasuyuki | 0:b32d0acc420d | 15 | |
yasuyuki | 0:b32d0acc420d | 16 | BME280::BME280 (PinName sda, PinName scl) : _i2c(sda, scl) { |
yasuyuki | 0:b32d0acc420d | 17 | init(); |
yasuyuki | 0:b32d0acc420d | 18 | } |
yasuyuki | 0:b32d0acc420d | 19 | BME280::BME280 (I2C& p_i2c) : _i2c(p_i2c) { |
yasuyuki | 0:b32d0acc420d | 20 | init(); |
yasuyuki | 0:b32d0acc420d | 21 | } |
yasuyuki | 0:b32d0acc420d | 22 | |
yasuyuki | 0:b32d0acc420d | 23 | |
yasuyuki | 0:b32d0acc420d | 24 | unsigned char BME280::get(unsigned char a) |
yasuyuki | 0:b32d0acc420d | 25 | { |
yasuyuki | 0:b32d0acc420d | 26 | |
yasuyuki | 0:b32d0acc420d | 27 | buf[0] = a; // register |
yasuyuki | 0:b32d0acc420d | 28 | _i2c.write(BME280_ADDR, buf, 1); // with stop |
yasuyuki | 0:b32d0acc420d | 29 | // get data |
yasuyuki | 0:b32d0acc420d | 30 | _i2c.read( BME280_ADDR, buf, 1); |
yasuyuki | 0:b32d0acc420d | 31 | return buf[0]; |
yasuyuki | 0:b32d0acc420d | 32 | |
yasuyuki | 0:b32d0acc420d | 33 | } |
yasuyuki | 0:b32d0acc420d | 34 | |
yasuyuki | 0:b32d0acc420d | 35 | void BME280::set(unsigned char a, unsigned char b) |
yasuyuki | 0:b32d0acc420d | 36 | { |
yasuyuki | 0:b32d0acc420d | 37 | |
yasuyuki | 0:b32d0acc420d | 38 | buf[0] = a; // register |
yasuyuki | 0:b32d0acc420d | 39 | buf[1] = b; |
yasuyuki | 0:b32d0acc420d | 40 | _i2c.write(BME280_ADDR, buf, 2); // with stop |
yasuyuki | 0:b32d0acc420d | 41 | |
yasuyuki | 0:b32d0acc420d | 42 | } |
yasuyuki | 0:b32d0acc420d | 43 | |
yasuyuki | 0:b32d0acc420d | 44 | |
yasuyuki | 0:b32d0acc420d | 45 | void BME280::getALL() |
yasuyuki | 0:b32d0acc420d | 46 | { |
yasuyuki | 0:b32d0acc420d | 47 | // set ctrl_meas : forced mode |
yasuyuki | 0:b32d0acc420d | 48 | set(ctrl_meas, 0x25); |
yasuyuki | 0:b32d0acc420d | 49 | |
yasuyuki | 1:0054d4a28927 | 50 | // wait 11.5ms for forced mode |
yasuyuki | 1:0054d4a28927 | 51 | wait_ms(12); |
yasuyuki | 1:0054d4a28927 | 52 | |
yasuyuki | 0:b32d0acc420d | 53 | // wait status |
yasuyuki | 0:b32d0acc420d | 54 | if(get(status) != 0)wait_ms(1); |
yasuyuki | 0:b32d0acc420d | 55 | |
yasuyuki | 0:b32d0acc420d | 56 | // get temp |
yasuyuki | 0:b32d0acc420d | 57 | temp.XLSB = get(temp_xlsb); |
yasuyuki | 0:b32d0acc420d | 58 | temp.LSB = get(temp_lsb); |
yasuyuki | 0:b32d0acc420d | 59 | temp.MSB = get(temp_msb); |
yasuyuki | 0:b32d0acc420d | 60 | temp.dummy = 0; |
yasuyuki | 0:b32d0acc420d | 61 | |
yasuyuki | 0:b32d0acc420d | 62 | // get press |
yasuyuki | 0:b32d0acc420d | 63 | press.XLSB = get(press_xlsb); |
yasuyuki | 0:b32d0acc420d | 64 | press.LSB = get(press_lsb); |
yasuyuki | 0:b32d0acc420d | 65 | press.MSB = get(press_msb); |
yasuyuki | 0:b32d0acc420d | 66 | press.dummy = 0; |
yasuyuki | 0:b32d0acc420d | 67 | |
yasuyuki | 0:b32d0acc420d | 68 | // get hum |
yasuyuki | 0:b32d0acc420d | 69 | hum.LSB = get(hum_lsb); |
yasuyuki | 0:b32d0acc420d | 70 | hum.MSB = get(hum_msb); |
yasuyuki | 0:b32d0acc420d | 71 | |
yasuyuki | 0:b32d0acc420d | 72 | |
yasuyuki | 0:b32d0acc420d | 73 | // compensation |
yasuyuki | 0:b32d0acc420d | 74 | t = BME280_compensate_T_int32(temp.s32>>12); |
yasuyuki | 0:b32d0acc420d | 75 | p = BME280_compensate_P_int64(press.s32>>12); |
yasuyuki | 0:b32d0acc420d | 76 | h = BME280_compensate_H_int32((signed int)hum.u16); |
yasuyuki | 0:b32d0acc420d | 77 | } |
yasuyuki | 0:b32d0acc420d | 78 | |
yasuyuki | 0:b32d0acc420d | 79 | unsigned int BME280::humidity() |
yasuyuki | 0:b32d0acc420d | 80 | { |
yasuyuki | 0:b32d0acc420d | 81 | |
yasuyuki | 0:b32d0acc420d | 82 | // get hum |
yasuyuki | 0:b32d0acc420d | 83 | getALL(); |
yasuyuki | 0:b32d0acc420d | 84 | return h; |
yasuyuki | 0:b32d0acc420d | 85 | |
yasuyuki | 0:b32d0acc420d | 86 | } |
yasuyuki | 0:b32d0acc420d | 87 | |
yasuyuki | 0:b32d0acc420d | 88 | signed int BME280::temperature() |
yasuyuki | 0:b32d0acc420d | 89 | { |
yasuyuki | 0:b32d0acc420d | 90 | |
yasuyuki | 0:b32d0acc420d | 91 | // get temp |
yasuyuki | 0:b32d0acc420d | 92 | getALL(); |
yasuyuki | 0:b32d0acc420d | 93 | return t; |
yasuyuki | 0:b32d0acc420d | 94 | |
yasuyuki | 0:b32d0acc420d | 95 | } |
yasuyuki | 0:b32d0acc420d | 96 | |
yasuyuki | 0:b32d0acc420d | 97 | unsigned int BME280::pressure() |
yasuyuki | 0:b32d0acc420d | 98 | { |
yasuyuki | 0:b32d0acc420d | 99 | |
yasuyuki | 0:b32d0acc420d | 100 | // get hum |
yasuyuki | 0:b32d0acc420d | 101 | getALL(); |
yasuyuki | 0:b32d0acc420d | 102 | return p; |
yasuyuki | 0:b32d0acc420d | 103 | |
yasuyuki | 0:b32d0acc420d | 104 | } |
yasuyuki | 0:b32d0acc420d | 105 | |
yasuyuki | 0:b32d0acc420d | 106 | void BME280::init() |
yasuyuki | 0:b32d0acc420d | 107 | { |
yasuyuki | 0:b32d0acc420d | 108 | |
yasuyuki | 0:b32d0acc420d | 109 | // get calibrations |
yasuyuki | 0:b32d0acc420d | 110 | calib.LSB = get(calib00); |
yasuyuki | 0:b32d0acc420d | 111 | calib.MSB = get(calib01); |
yasuyuki | 0:b32d0acc420d | 112 | dig_T1 = calib.u16; |
yasuyuki | 0:b32d0acc420d | 113 | calib.LSB = get(calib02); |
yasuyuki | 0:b32d0acc420d | 114 | calib.MSB = get(calib03); |
yasuyuki | 0:b32d0acc420d | 115 | dig_T2 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 116 | calib.LSB = get(calib04); |
yasuyuki | 0:b32d0acc420d | 117 | calib.MSB = get(calib05); |
yasuyuki | 0:b32d0acc420d | 118 | dig_T3 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 119 | calib.LSB = get(calib06); |
yasuyuki | 0:b32d0acc420d | 120 | calib.MSB = get(calib07); |
yasuyuki | 0:b32d0acc420d | 121 | dig_P1 = calib.u16; |
yasuyuki | 0:b32d0acc420d | 122 | calib.LSB = get(calib08); |
yasuyuki | 0:b32d0acc420d | 123 | calib.MSB = get(calib09); |
yasuyuki | 0:b32d0acc420d | 124 | dig_P2 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 125 | calib.LSB = get(calib10); |
yasuyuki | 0:b32d0acc420d | 126 | calib.MSB = get(calib11); |
yasuyuki | 0:b32d0acc420d | 127 | dig_P3 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 128 | calib.LSB = get(calib12); |
yasuyuki | 0:b32d0acc420d | 129 | calib.MSB = get(calib13); |
yasuyuki | 0:b32d0acc420d | 130 | dig_P4 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 131 | calib.LSB = get(calib14); |
yasuyuki | 0:b32d0acc420d | 132 | calib.MSB = get(calib15); |
yasuyuki | 0:b32d0acc420d | 133 | dig_P5 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 134 | calib.LSB = get(calib16); |
yasuyuki | 0:b32d0acc420d | 135 | calib.MSB = get(calib17); |
yasuyuki | 0:b32d0acc420d | 136 | dig_P6 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 137 | calib.LSB = get(calib18); |
yasuyuki | 0:b32d0acc420d | 138 | calib.MSB = get(calib19); |
yasuyuki | 0:b32d0acc420d | 139 | dig_P7 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 140 | calib.LSB = get(calib20); |
yasuyuki | 0:b32d0acc420d | 141 | calib.MSB = get(calib21); |
yasuyuki | 0:b32d0acc420d | 142 | dig_P8 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 143 | calib.LSB = get(calib22); |
yasuyuki | 0:b32d0acc420d | 144 | calib.MSB = get(calib23); |
yasuyuki | 0:b32d0acc420d | 145 | dig_P9 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 146 | dig_H1 = get(calib25); |
yasuyuki | 0:b32d0acc420d | 147 | calib.LSB = get(calib26); |
yasuyuki | 0:b32d0acc420d | 148 | calib.MSB = get(calib27); |
yasuyuki | 0:b32d0acc420d | 149 | dig_H2 = calib.s16; |
yasuyuki | 0:b32d0acc420d | 150 | dig_H3 = get(calib28); |
yasuyuki | 0:b32d0acc420d | 151 | calib.MSB = get(calib29); |
yasuyuki | 0:b32d0acc420d | 152 | calib.LSB = get(calib30) << 4; |
yasuyuki | 0:b32d0acc420d | 153 | dig_H4 = calib.s16>>4; |
yasuyuki | 0:b32d0acc420d | 154 | calib.LSB = get(calib30); |
yasuyuki | 0:b32d0acc420d | 155 | calib.MSB = get(calib31); |
yasuyuki | 0:b32d0acc420d | 156 | dig_H5 = calib.s16>>4; |
yasuyuki | 0:b32d0acc420d | 157 | dig_H6 = get(calib32); |
yasuyuki | 0:b32d0acc420d | 158 | |
yasuyuki | 0:b32d0acc420d | 159 | // Set configuration |
yasuyuki | 0:b32d0acc420d | 160 | set(config, 0x00); |
yasuyuki | 0:b32d0acc420d | 161 | set(ctrl_hum, 0x01); |
yasuyuki | 0:b32d0acc420d | 162 | |
yasuyuki | 0:b32d0acc420d | 163 | } |
yasuyuki | 0:b32d0acc420d | 164 | |
yasuyuki | 0:b32d0acc420d | 165 | // Returns temperature in DegC, resolution is 0.01 DegC. Output value of "5123" equals 51.23 DegC. |
yasuyuki | 0:b32d0acc420d | 166 | // t_fine carries fine temperature as global value |
yasuyuki | 0:b32d0acc420d | 167 | BME280_S32_t BME280::BME280_compensate_T_int32(BME280_S32_t adc_T) |
yasuyuki | 0:b32d0acc420d | 168 | { |
yasuyuki | 0:b32d0acc420d | 169 | BME280_S32_t var1, var2, T; |
yasuyuki | 0:b32d0acc420d | 170 | var1 = ((((adc_T>>3) - ((BME280_S32_t)dig_T1<<1))) * ((BME280_S32_t)dig_T2)) >> 11; |
yasuyuki | 0:b32d0acc420d | 171 | var2 = (((((adc_T>>4) - ((BME280_S32_t)dig_T1)) * ((adc_T>>4) - ((BME280_S32_t)dig_T1))) >> 12) * |
yasuyuki | 0:b32d0acc420d | 172 | ((BME280_S32_t)dig_T3)) >> 14; |
yasuyuki | 0:b32d0acc420d | 173 | t_fine = var1 + var2; |
yasuyuki | 0:b32d0acc420d | 174 | T = (t_fine * 5 + 128) >> 8; |
yasuyuki | 0:b32d0acc420d | 175 | return T; |
yasuyuki | 0:b32d0acc420d | 176 | } |
yasuyuki | 0:b32d0acc420d | 177 | |
yasuyuki | 0:b32d0acc420d | 178 | // Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24 integer bits and 8 fractional bits). |
yasuyuki | 0:b32d0acc420d | 179 | // Output value of "24674867" represents 24674867/256 = 96386.2 Pa = 963.862 hPa |
yasuyuki | 0:b32d0acc420d | 180 | BME280_U32_t BME280::BME280_compensate_P_int64(BME280_S32_t adc_P) |
yasuyuki | 0:b32d0acc420d | 181 | { |
yasuyuki | 0:b32d0acc420d | 182 | BME280_S64_t var1, var2, p; |
yasuyuki | 0:b32d0acc420d | 183 | var1 = ((BME280_S64_t)t_fine) - 128000; |
yasuyuki | 0:b32d0acc420d | 184 | var2 = var1 * var1 * (BME280_S64_t)dig_P6; |
yasuyuki | 0:b32d0acc420d | 185 | var2 = var2 + ((var1*(BME280_S64_t)dig_P5)<<17); |
yasuyuki | 0:b32d0acc420d | 186 | var2 = var2 + (((BME280_S64_t)dig_P4)<<35); |
yasuyuki | 0:b32d0acc420d | 187 | var1 = ((var1 * var1 * (BME280_S64_t)dig_P3)>>8) + ((var1 * (BME280_S64_t)dig_P2)<<12); |
yasuyuki | 0:b32d0acc420d | 188 | var1 = (((((BME280_S64_t)1)<<47)+var1))*((BME280_S64_t)dig_P1)>>33; |
yasuyuki | 0:b32d0acc420d | 189 | if (var1 == 0) |
yasuyuki | 0:b32d0acc420d | 190 | { |
yasuyuki | 0:b32d0acc420d | 191 | return 0; // avoid exception caused by division by zero |
yasuyuki | 0:b32d0acc420d | 192 | } |
yasuyuki | 0:b32d0acc420d | 193 | p = 1048576-adc_P; |
yasuyuki | 0:b32d0acc420d | 194 | p = (((p<<31)-var2)*3125)/var1; |
yasuyuki | 0:b32d0acc420d | 195 | var1 = (((BME280_S64_t)dig_P9) * (p>>13) * (p>>13)) >> 25; |
yasuyuki | 0:b32d0acc420d | 196 | var2 = (((BME280_S64_t)dig_P8) * p) >> 19; |
yasuyuki | 0:b32d0acc420d | 197 | p = ((p + var1 + var2) >> 8) + (((BME280_S64_t)dig_P7)<<4); |
yasuyuki | 0:b32d0acc420d | 198 | return (BME280_U32_t)p; |
yasuyuki | 0:b32d0acc420d | 199 | } |
yasuyuki | 0:b32d0acc420d | 200 | |
yasuyuki | 0:b32d0acc420d | 201 | // Returns humidity in %RH as unsigned 32 bit integer in Q22.10 format (22 integer and 10 fractional bits). |
yasuyuki | 0:b32d0acc420d | 202 | // Output value of "47445" represents 47445/1024 = 46.333 %RH |
yasuyuki | 0:b32d0acc420d | 203 | BME280_U32_t BME280::BME280_compensate_H_int32(BME280_S32_t adc_H) |
yasuyuki | 0:b32d0acc420d | 204 | { |
yasuyuki | 0:b32d0acc420d | 205 | BME280_S32_t v_x1_u32r; |
yasuyuki | 0:b32d0acc420d | 206 | v_x1_u32r = (t_fine - ((BME280_S32_t)76800)); |
yasuyuki | 0:b32d0acc420d | 207 | v_x1_u32r = (((((adc_H << 14) - (((BME280_S32_t)dig_H4) << 20) - (((BME280_S32_t)dig_H5) * v_x1_u32r)) + |
yasuyuki | 0:b32d0acc420d | 208 | ((BME280_S32_t)16384)) >> 15) * (((((((v_x1_u32r * ((BME280_S32_t)dig_H6)) >> 10) * (((v_x1_u32r * |
yasuyuki | 0:b32d0acc420d | 209 | ((BME280_S32_t)dig_H3)) >> 11) + ((BME280_S32_t)32768))) >> 10) + ((BME280_S32_t)2097152)) * |
yasuyuki | 0:b32d0acc420d | 210 | ((BME280_S32_t)dig_H2) + 8192) >> 14)); |
yasuyuki | 0:b32d0acc420d | 211 | v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((BME280_S32_t)dig_H1)) >> 4)); |
yasuyuki | 0:b32d0acc420d | 212 | v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r); |
yasuyuki | 0:b32d0acc420d | 213 | v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r); |
yasuyuki | 0:b32d0acc420d | 214 | return (BME280_U32_t)(v_x1_u32r>>12); |
yasuyuki | 0:b32d0acc420d | 215 | } |
yasuyuki | 0:b32d0acc420d | 216 |