Daisuke Nakayama / BME280

BME280にアクセスするためのライブラリ

BME280.cpp@3:df1107ddf502, 2018-07-10 (annotated)

Committer:
j_rocket_boy
Date:
Tue Jul 10 08:57:26 2018 +0000
Revision:
3:df1107ddf502
Parent:
2:42725d11023b
Child:
4:4c4e3ec9a2c4
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Who changed what in which revision?

UserRevisionLine numberNew contents of line
j_rocket_boy 0:95f2b96cdc7f 1 #include "mbed.h"
j_rocket_boy 0:95f2b96cdc7f 2 #include "BME280.h"
j_rocket_boy 0:95f2b96cdc7f 3 #include "i2c_general_io.h"
j_rocket_boy 0:95f2b96cdc7f 4
j_rocket_boy 3:df1107ddf502 5 //コンストラクタ１
j_rocket_boy 3:df1107ddf502 6 BME280::BME280(PinName sda, PinName scl,
j_rocket_boy 3:df1107ddf502 7 char mode,
j_rocket_boy 3:df1107ddf502 8 char press_sample,
j_rocket_boy 3:df1107ddf502 9 char temp_sample,
j_rocket_boy 3:df1107ddf502 10 char hum_sample,
j_rocket_boy 3:df1107ddf502 11 char filter,
j_rocket_boy 3:df1107ddf502 12 char stanby)
j_rocket_boy 0:95f2b96cdc7f 13 :
j_rocket_boy 0:95f2b96cdc7f 14 i2c_p(new GEN_I2C(sda, scl)),
j_rocket_boy 0:95f2b96cdc7f 15 sensor(*i2c_p)
j_rocket_boy 0:95f2b96cdc7f 16 {
j_rocket_boy 3:df1107ddf502 17 _mode = mode;
j_rocket_boy 3:df1107ddf502 18 _press_sample = press_sample;
j_rocket_boy 3:df1107ddf502 19 _temp_sample = temp_sample;
j_rocket_boy 3:df1107ddf502 20 _hum_sample = hum_sample;
j_rocket_boy 3:df1107ddf502 21 _filter = filter;
j_rocket_boy 3:df1107ddf502 22 _stanby = stanby;
j_rocket_boy 0:95f2b96cdc7f 23 init();
j_rocket_boy 0:95f2b96cdc7f 24 }
j_rocket_boy 0:95f2b96cdc7f 25
j_rocket_boy 3:df1107ddf502 26 //コンストラクタ２
j_rocket_boy 3:df1107ddf502 27 BME280::BME280(GEN_I2C &i2c_obj,
j_rocket_boy 3:df1107ddf502 28 char mode,
j_rocket_boy 3:df1107ddf502 29 char press_sample,
j_rocket_boy 3:df1107ddf502 30 char temp_sample,
j_rocket_boy 3:df1107ddf502 31 char hum_sample,
j_rocket_boy 3:df1107ddf502 32 char filter,
j_rocket_boy 3:df1107ddf502 33 char stanby)
j_rocket_boy 0:95f2b96cdc7f 34 :
j_rocket_boy 0:95f2b96cdc7f 35 i2c_p(NULL),
j_rocket_boy 0:95f2b96cdc7f 36 sensor(i2c_obj)
j_rocket_boy 0:95f2b96cdc7f 37 {
j_rocket_boy 3:df1107ddf502 38 _mode = mode;
j_rocket_boy 3:df1107ddf502 39 _press_sample = press_sample;
j_rocket_boy 3:df1107ddf502 40 _temp_sample = temp_sample;
j_rocket_boy 3:df1107ddf502 41 _hum_sample = hum_sample;
j_rocket_boy 3:df1107ddf502 42 _filter = filter;
j_rocket_boy 3:df1107ddf502 43 _stanby = stanby;
j_rocket_boy 0:95f2b96cdc7f 44 init();
j_rocket_boy 0:95f2b96cdc7f 45 }
j_rocket_boy 0:95f2b96cdc7f 46
j_rocket_boy 3:df1107ddf502 47 //デストラクタ
j_rocket_boy 0:95f2b96cdc7f 48 BME280::~BME280()
j_rocket_boy 0:95f2b96cdc7f 49 {
j_rocket_boy 0:95f2b96cdc7f 50 if (NULL != i2c_p)
j_rocket_boy 0:95f2b96cdc7f 51 delete i2c_p;
j_rocket_boy 0:95f2b96cdc7f 52 }
j_rocket_boy 0:95f2b96cdc7f 53
j_rocket_boy 3:df1107ddf502 54 //センサーからデータ読み取り
j_rocket_boy 0:95f2b96cdc7f 55 void BME280::read_sensor(void){
j_rocket_boy 0:95f2b96cdc7f 56 char sensor_raw_data[8];
j_rocket_boy 1:0dbf59c6e564 57 long signed int T,P,H; //ADC読み込み後温度，気圧，湿度の生データ
j_rocket_boy 1:0dbf59c6e564 58 long signed int T_cor; //温度の補正データ
j_rocket_boy 1:0dbf59c6e564 59 long unsigned int P_cor,H_cor; //気圧，湿度の補正データ
j_rocket_boy 0:95f2b96cdc7f 60
j_rocket_boy 3:df1107ddf502 61
j_rocket_boy 0:95f2b96cdc7f 62 //読み込み
j_rocket_boy 3:df1107ddf502 63
j_rocket_boy 3:df1107ddf502 64 //ノーマルモードでないとき
j_rocket_boy 3:df1107ddf502 65 if( _mode != BME280_NORMAL_MODE ){
j_rocket_boy 3:df1107ddf502 66 set_force_mode(); //強制モードで測定開始
j_rocket_boy 3:df1107ddf502 67 while(BME280_STATUS_IS_MEASURING); //測定待ち
j_rocket_boy 3:df1107ddf502 68 }
j_rocket_boy 3:df1107ddf502 69
j_rocket_boy 3:df1107ddf502 70 sensor.read_reg(BME280_add, BME280_PRESS_MSB, sensor_raw_data, 8); //PRESS_MSBレジスタから8バイト読み込み
j_rocket_boy 3:df1107ddf502 71
j_rocket_boy 3:df1107ddf502 72 //ビットシフトしてデータを結合
j_rocket_boy 0:95f2b96cdc7f 73 T = sensor_raw_data[3] << 12 | sensor_raw_data[4] << 4 | sensor_raw_data[5] >> 4 ;
j_rocket_boy 0:95f2b96cdc7f 74 P = sensor_raw_data[0] << 12 | sensor_raw_data[1] << 4 | sensor_raw_data[2] >> 4 ;
j_rocket_boy 0:95f2b96cdc7f 75 H = sensor_raw_data[6] << 8 | sensor_raw_data[7];
j_rocket_boy 0:95f2b96cdc7f 76
j_rocket_boy 3:df1107ddf502 77
j_rocket_boy 0:95f2b96cdc7f 78 //補正
j_rocket_boy 0:95f2b96cdc7f 79 T_cor = BME280_compensate_T_int32(T);
j_rocket_boy 0:95f2b96cdc7f 80 P_cor = BME280_compensate_P_int64(P);
j_rocket_boy 0:95f2b96cdc7f 81 H_cor = BME280_compensate_H_int32(H);
j_rocket_boy 3:df1107ddf502 82
j_rocket_boy 0:95f2b96cdc7f 83
j_rocket_boy 3:df1107ddf502 84 //不動小数点数に直す
j_rocket_boy 3:df1107ddf502 85 press = P_cor / 256.0; //単位Pa
j_rocket_boy 3:df1107ddf502 86 temp = T_cor / 100.0; //単位℃
j_rocket_boy 3:df1107ddf502 87 hum = H_cor / 1024.0; //単位％
j_rocket_boy 3:df1107ddf502 88
j_rocket_boy 0:95f2b96cdc7f 89 }
j_rocket_boy 0:95f2b96cdc7f 90
j_rocket_boy 3:df1107ddf502 91 //強制測定モードをセットする関数。
j_rocket_boy 3:df1107ddf502 92 inline void BME280::set_force_mode(void){
j_rocket_boy 3:df1107ddf502 93 sensor.write_reg(BME280_add, BME280_CTRL_MEAS, (_press_sample & 0x1C) | (_temp_sample & 0xE0) | BME280_FORCE_MODE );
j_rocket_boy 0:95f2b96cdc7f 94 }
j_rocket_boy 0:95f2b96cdc7f 95
j_rocket_boy 0:95f2b96cdc7f 96
j_rocket_boy 0:95f2b96cdc7f 97 //データシートより，補正関数
j_rocket_boy 0:95f2b96cdc7f 98 // 温度を℃で返します。分解能は0.01℃です。「5123」の出力値は、51.23℃に相当します。
j_rocket_boy 0:95f2b96cdc7f 99 // t_fineは、グローバル値として細かい温度値を持ちます。
j_rocket_boy 1:0dbf59c6e564 100 long signed int BME280::BME280_compensate_T_int32(long signed int adc_T){
j_rocket_boy 1:0dbf59c6e564 101 long signed int var1, var2, T;
j_rocket_boy 1:0dbf59c6e564 102 var1 = ((((adc_T>>3) - ((long signed int)dig_T1<<1))) * ((long signed int)dig_T2)) >> 11;
j_rocket_boy 1:0dbf59c6e564 103 var2 = (((((adc_T>>4) - ((long signed int)dig_T1)) * ((adc_T>>4) - ((long signed int)dig_T1))) >> 12) *
j_rocket_boy 1:0dbf59c6e564 104 ((long signed int)dig_T3)) >> 14;
j_rocket_boy 0:95f2b96cdc7f 105 t_fine = var1 + var2;
j_rocket_boy 0:95f2b96cdc7f 106 T = (t_fine * 5 + 128) >> 8;
j_rocket_boy 0:95f2b96cdc7f 107 return T;
j_rocket_boy 0:95f2b96cdc7f 108 }
j_rocket_boy 0:95f2b96cdc7f 109
j_rocket_boy 0:95f2b96cdc7f 110 // 圧力（Pa）を、Q24.8形式の符号なし32ビット整数として返します。（24個の整数ビットと8個の小数ビット）
j_rocket_boy 0:95f2b96cdc7f 111 // 「24674867」の出力値は、24674867/256 = 96386.2Pa = 963.862hPaに相当します。
j_rocket_boy 1:0dbf59c6e564 112 long unsigned int BME280::BME280_compensate_P_int64(long signed int adc_P){
j_rocket_boy 1:0dbf59c6e564 113 long long signed int var1, var2, p;
j_rocket_boy 1:0dbf59c6e564 114 var1 = ((long long signed int)t_fine) - 128000;
j_rocket_boy 1:0dbf59c6e564 115 var2 = var1 * var1 * (long long signed int)dig_P6;
j_rocket_boy 1:0dbf59c6e564 116 var2 = var2 + ((var1*(long long signed int)dig_P5)<<17);
j_rocket_boy 1:0dbf59c6e564 117 var2 = var2 + (((long long signed int)dig_P4)<<35);
j_rocket_boy 1:0dbf59c6e564 118 var1 = ((var1 * var1 * (long long signed int)dig_P3)>>8) + ((var1 * (long long signed int)dig_P2)<<12);
j_rocket_boy 1:0dbf59c6e564 119 var1 = (((((long long signed int)1)<<47)+var1))*((long long signed int)dig_P1)>>33;
j_rocket_boy 0:95f2b96cdc7f 120 if (var1 == 0){
j_rocket_boy 0:95f2b96cdc7f 121 return 0; // ゼロ除算による例外を避ける。
j_rocket_boy 0:95f2b96cdc7f 122 }
j_rocket_boy 0:95f2b96cdc7f 123 p = 1048576-adc_P;
j_rocket_boy 0:95f2b96cdc7f 124 p = (((p<<31)-var2)*3125)/var1;
j_rocket_boy 1:0dbf59c6e564 125 var1 = (((long long signed int)dig_P9) * (p>>13) * (p>>13)) >> 25;
j_rocket_boy 1:0dbf59c6e564 126 var2 = (((long long signed int)dig_P8) * p) >> 19;
j_rocket_boy 1:0dbf59c6e564 127 p = ((p + var1 + var2) >> 8) + (((long long signed int)dig_P7)<<4);
j_rocket_boy 1:0dbf59c6e564 128 return (long unsigned int)p;
j_rocket_boy 0:95f2b96cdc7f 129 }
j_rocket_boy 0:95f2b96cdc7f 130
j_rocket_boy 0:95f2b96cdc7f 131 // 湿度（%RH）を、Q22.10形式の符号なし32ビット整数として返します。（22個の整数と10個の小数ビット）
j_rocket_boy 0:95f2b96cdc7f 132 // 「47445」の出力値は、47445/1024 = 46.333%RHに相当します。
j_rocket_boy 1:0dbf59c6e564 133 long unsigned int BME280::BME280_compensate_H_int32(long signed int adc_H){
j_rocket_boy 1:0dbf59c6e564 134 long signed int v_x1_u32r;
j_rocket_boy 1:0dbf59c6e564 135 v_x1_u32r = (t_fine - ((long signed int)76800));
j_rocket_boy 1:0dbf59c6e564 136 v_x1_u32r = (((((adc_H << 14) - (((long signed int)dig_H4) << 20) - (((long signed int)dig_H5) * v_x1_u32r)) +
j_rocket_boy 1:0dbf59c6e564 137 ((long signed int)16384)) >> 15) * (((((((v_x1_u32r * ((long signed int)dig_H6)) >> 10) * (((v_x1_u32r *
j_rocket_boy 1:0dbf59c6e564 138 ((long signed int)dig_H3)) >> 11) + ((long signed int)32768))) >> 10) + ((long signed int)2097152)) *
j_rocket_boy 1:0dbf59c6e564 139 ((long signed int)dig_H2) + 8192) >> 14));
j_rocket_boy 1:0dbf59c6e564 140 v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((long signed int)dig_H1)) >> 4));
j_rocket_boy 0:95f2b96cdc7f 141 v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r);
j_rocket_boy 0:95f2b96cdc7f 142 v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r);
j_rocket_boy 1:0dbf59c6e564 143 return (long unsigned int)(v_x1_u32r>>12);
j_rocket_boy 0:95f2b96cdc7f 144 }
j_rocket_boy 0:95f2b96cdc7f 145 //補正関数終わり
j_rocket_boy 0:95f2b96cdc7f 146
j_rocket_boy 3:df1107ddf502 147 //初期化関数
j_rocket_boy 0:95f2b96cdc7f 148 void BME280::init(void){
j_rocket_boy 3:df1107ddf502 149
j_rocket_boy 3:df1107ddf502 150 char calib[32] = {0}; //補正係数読み取り用
j_rocket_boy 3:df1107ddf502 151 char reg_data; //レジスタ読み取り用
j_rocket_boy 0:95f2b96cdc7f 152
j_rocket_boy 3:df1107ddf502 153 //リセット
j_rocket_boy 3:df1107ddf502 154 sensor.write_reg(BME280_add, BME280_RESET_REG, BME280_RESET_VALUE);
j_rocket_boy 3:df1107ddf502 155
j_rocket_boy 3:df1107ddf502 156 //ID読み込み
j_rocket_boy 3:df1107ddf502 157 reg_data = sensor.read_reg(BME280_add,BME280_ID);
j_rocket_boy 3:df1107ddf502 158 if(reg_data != BME280_ID_VALUE){ //ID不一致エラー
j_rocket_boy 0:95f2b96cdc7f 159 printf("error\n");
j_rocket_boy 0:95f2b96cdc7f 160 while(1);
j_rocket_boy 0:95f2b96cdc7f 161 }
j_rocket_boy 3:df1107ddf502 162
j_rocket_boy 3:df1107ddf502 163 //不揮発メモリのデータのレジスタコピー待ち
j_rocket_boy 3:df1107ddf502 164 while(BME280_STATUS_IS_COPYING);
j_rocket_boy 0:95f2b96cdc7f 165
j_rocket_boy 0:95f2b96cdc7f 166 //ADC補償式用定数読み込み
j_rocket_boy 3:df1107ddf502 167 sensor.read_reg(BME280_add, BME280_CALIB00, &(calib[0]), 24);
j_rocket_boy 3:df1107ddf502 168 sensor.read_reg(BME280_add, BME280_CALIB25, &(calib[24]), 1);
j_rocket_boy 3:df1107ddf502 169 sensor.read_reg(BME280_add, BME280_CALIB26, &(calib[25]), 7);
j_rocket_boy 0:95f2b96cdc7f 170
j_rocket_boy 3:df1107ddf502 171 //ビットシフトして対応する変数に格納（温度補正係数）
j_rocket_boy 0:95f2b96cdc7f 172 dig_T1 = calib[ 0] | (calib[ 1] << 8);
j_rocket_boy 0:95f2b96cdc7f 173 dig_T2 = calib[ 2] | (calib[ 3] << 8);
j_rocket_boy 0:95f2b96cdc7f 174 dig_T3 = calib[ 4] | (calib[ 5] << 8);
j_rocket_boy 0:95f2b96cdc7f 175
j_rocket_boy 3:df1107ddf502 176 //ビットシフトして対応する変数に格納（気圧補正係数）
j_rocket_boy 0:95f2b96cdc7f 177 dig_P1 = calib[ 6] | (calib[ 7] << 8);
j_rocket_boy 0:95f2b96cdc7f 178 dig_P2 = calib[ 8] | (calib[ 9] << 8);
j_rocket_boy 0:95f2b96cdc7f 179 dig_P3 = calib[10] | (calib[11] << 8);
j_rocket_boy 0:95f2b96cdc7f 180 dig_P4 = calib[12] | (calib[13] << 8);
j_rocket_boy 0:95f2b96cdc7f 181 dig_P5 = calib[14] | (calib[15] << 8);
j_rocket_boy 0:95f2b96cdc7f 182 dig_P6 = calib[16] | (calib[17] << 8);
j_rocket_boy 0:95f2b96cdc7f 183 dig_P7 = calib[18] | (calib[19] << 8);
j_rocket_boy 0:95f2b96cdc7f 184 dig_P8 = calib[20] | (calib[21] << 8);
j_rocket_boy 0:95f2b96cdc7f 185 dig_P9 = calib[22] | (calib[23] << 8);
j_rocket_boy 0:95f2b96cdc7f 186
j_rocket_boy 3:df1107ddf502 187 //ビットシフトして対応する変数に格納（湿度補正係数）
j_rocket_boy 0:95f2b96cdc7f 188 dig_H1 = calib[24];
j_rocket_boy 0:95f2b96cdc7f 189 dig_H2 = calib[25] | (calib[26] << 8);
j_rocket_boy 0:95f2b96cdc7f 190 dig_H3 = calib[27];
j_rocket_boy 0:95f2b96cdc7f 191 dig_H4 = (calib[28]<<4) | (calib[29] & 0x0F);
j_rocket_boy 0:95f2b96cdc7f 192 dig_H5 = ((calib[29]>>4) & 0x0F) | (calib[30] << 4);
j_rocket_boy 0:95f2b96cdc7f 193 dig_H6 = calib[31];
j_rocket_boy 0:95f2b96cdc7f 194
j_rocket_boy 0:95f2b96cdc7f 195 //センサ設定
j_rocket_boy 3:df1107ddf502 196 sensor.write_reg(BME280_add, BME280_CTRL_HUM , (_hum_sample & 0x07) );
j_rocket_boy 3:df1107ddf502 197 sensor.write_reg(BME280_add, BME280_CTRL_MEAS, (_press_sample & 0x1C) | (_temp_sample & 0xE0) | (_mode & 0x03) );
j_rocket_boy 3:df1107ddf502 198 sensor.write_reg(BME280_add, BME280_CONFIG , (_stanby & 0xE0) | (_filter & 0x1C) );
j_rocket_boy 0:95f2b96cdc7f 199
j_rocket_boy 0:95f2b96cdc7f 200 }
j_rocket_boy 0:95f2b96cdc7f 201
j_rocket_boy 0:95f2b96cdc7f 202