BME280にアクセスするためのライブラリ
BME280.cpp
- Committer:
- j_rocket_boy
- Date:
- 2018-07-11
- Revision:
- 8:c5f2c8022931
- Parent:
- 4:4c4e3ec9a2c4
File content as of revision 8:c5f2c8022931:
// -*- coding: utf-8 -*- /** @file BME280.cpp @brief MBE280のライブラリ @author D.Nakayama @version 1.0 @date 2018-07-10 D.Nakayama Written for C++/mbed. @see Copyright (C) 2018 D.Nakayama. Released under the MIT license. http://opensource.org/licenses/mit-license.php */ #include "mbed.h" #include "BME280.h" #include "i2c_general_io.h" //コンストラクタ1 BME280::BME280(PinName sda, PinName scl, char mode, char press_sample, char temp_sample, char hum_sample, char filter, char stanby) : i2c_p(new GEN_I2C(sda, scl)), sensor(*i2c_p) { _mode = mode; _press_sample = press_sample; _temp_sample = temp_sample; _hum_sample = hum_sample; _filter = filter; _stanby = stanby; init(); } //コンストラクタ2 BME280::BME280(GEN_I2C &i2c_obj, char mode, char press_sample, char temp_sample, char hum_sample, char filter, char stanby) : i2c_p(NULL), sensor(i2c_obj) { _mode = mode; _press_sample = press_sample; _temp_sample = temp_sample; _hum_sample = hum_sample; _filter = filter; _stanby = stanby; init(); } //デストラクタ BME280::~BME280() { if (NULL != i2c_p) delete i2c_p; } //センサーからデータ読み取り void BME280::read_sensor(void){ char sensor_raw_data[8]; long signed int T,P,H; //ADC読み込み後温度,気圧,湿度の生データ long signed int T_cor; //温度の補正データ long unsigned int P_cor,H_cor; //気圧,湿度の補正データ //読み込み //ノーマルモードでないとき if( _mode != BME280_NORMAL_MODE ){ set_force_mode(); //強制モードで測定開始 while(BME280_STATUS_IS_MEASURING); //測定待ち } 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 //ビットシフトしてデータを結合 T = sensor_raw_data[3] << 12 | sensor_raw_data[4] << 4 | sensor_raw_data[5] >> 4 ; P = sensor_raw_data[0] << 12 | sensor_raw_data[1] << 4 | sensor_raw_data[2] >> 4 ; H = sensor_raw_data[6] << 8 | sensor_raw_data[7]; //補正 T_cor = BME280_compensate_T_int32(T); P_cor = BME280_compensate_P_int64(P); H_cor = BME280_compensate_H_int32(H); //不動小数点数に直す press = P_cor / 256.0; //単位Pa temp = T_cor / 100.0; //単位℃ hum = H_cor / 1024.0; //単位% } //強制測定モードをセットする関数。 inline void BME280::set_force_mode(void){ sensor.write_reg(BME280_add, BME280_CTRL_MEAS, (_press_sample & 0x1C) | (_temp_sample & 0xE0) | BME280_FORCE_MODE ); } //データシートより,補正関数 // 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。 // t_fineは、グローバル値として細かい温度値を持ちます。 long signed int BME280::BME280_compensate_T_int32(long signed int adc_T){ long signed int var1, var2, T; var1 = ((((adc_T>>3) - ((long signed int)dig_T1<<1))) * ((long signed int)dig_T2)) >> 11; var2 = (((((adc_T>>4) - ((long signed int)dig_T1)) * ((adc_T>>4) - ((long signed int)dig_T1))) >> 12) * ((long signed int)dig_T3)) >> 14; t_fine = var1 + var2; T = (t_fine * 5 + 128) >> 8; return T; } // 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) // 「24674867」の出力値は、24674867/256 = 96386.2Pa = 963.862hPaに相当します。 long unsigned int BME280::BME280_compensate_P_int64(long signed int adc_P){ long long signed int var1, var2, p; var1 = ((long long signed int)t_fine) - 128000; var2 = var1 * var1 * (long long signed int)dig_P6; var2 = var2 + ((var1*(long long signed int)dig_P5)<<17); var2 = var2 + (((long long signed int)dig_P4)<<35); var1 = ((var1 * var1 * (long long signed int)dig_P3)>>8) + ((var1 * (long long signed int)dig_P2)<<12); var1 = (((((long long signed int)1)<<47)+var1))*((long long signed int)dig_P1)>>33; if (var1 == 0){ return 0; // ゼロ除算による例外を避ける。 } p = 1048576-adc_P; p = (((p<<31)-var2)*3125)/var1; var1 = (((long long signed int)dig_P9) * (p>>13) * (p>>13)) >> 25; var2 = (((long long signed int)dig_P8) * p) >> 19; p = ((p + var1 + var2) >> 8) + (((long long signed int)dig_P7)<<4); return (long unsigned int)p; } // 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) // 「47445」の出力値は、47445/1024 = 46.333%RHに相当します。 long unsigned int BME280::BME280_compensate_H_int32(long signed int adc_H){ long signed int v_x1_u32r; v_x1_u32r = (t_fine - ((long signed int)76800)); v_x1_u32r = (((((adc_H << 14) - (((long signed int)dig_H4) << 20) - (((long signed int)dig_H5) * v_x1_u32r)) + ((long signed int)16384)) >> 15) * (((((((v_x1_u32r * ((long signed int)dig_H6)) >> 10) * (((v_x1_u32r * ((long signed int)dig_H3)) >> 11) + ((long signed int)32768))) >> 10) + ((long signed int)2097152)) * ((long signed int)dig_H2) + 8192) >> 14)); v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((long signed int)dig_H1)) >> 4)); v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r); v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r); return (long unsigned int)(v_x1_u32r>>12); } //補正関数終わり //初期化関数 void BME280::init(void){ char calib[32] = {0}; //補正係数読み取り用 char reg_data; //レジスタ読み取り用 //リセット sensor.write_reg(BME280_add, BME280_RESET_REG, BME280_RESET_VALUE); //ID読み込み reg_data = sensor.read_reg(BME280_add,BME280_ID); if(reg_data != BME280_ID_VALUE){ //ID不一致エラー printf("error\n"); while(1); } //不揮発メモリのデータのレジスタコピー待ち while(BME280_STATUS_IS_COPYING); //ADC補償式用定数読み込み sensor.read_reg(BME280_add, BME280_CALIB00, &(calib[0]), 24); sensor.read_reg(BME280_add, BME280_CALIB25, &(calib[24]), 1); sensor.read_reg(BME280_add, BME280_CALIB26, &(calib[25]), 7); //ビットシフトして対応する変数に格納(温度補正係数) dig_T1 = calib[ 0] | (calib[ 1] << 8); dig_T2 = calib[ 2] | (calib[ 3] << 8); dig_T3 = calib[ 4] | (calib[ 5] << 8); //ビットシフトして対応する変数に格納(気圧補正係数) dig_P1 = calib[ 6] | (calib[ 7] << 8); dig_P2 = calib[ 8] | (calib[ 9] << 8); dig_P3 = calib[10] | (calib[11] << 8); dig_P4 = calib[12] | (calib[13] << 8); dig_P5 = calib[14] | (calib[15] << 8); dig_P6 = calib[16] | (calib[17] << 8); dig_P7 = calib[18] | (calib[19] << 8); dig_P8 = calib[20] | (calib[21] << 8); dig_P9 = calib[22] | (calib[23] << 8); //ビットシフトして対応する変数に格納(湿度補正係数) dig_H1 = calib[24]; dig_H2 = calib[25] | (calib[26] << 8); dig_H3 = calib[27]; dig_H4 = (calib[28]<<4) | (calib[29] & 0x0F); dig_H5 = ((calib[29]>>4) & 0x0F) | (calib[30] << 4); dig_H6 = calib[31]; //センサ設定 sensor.write_reg(BME280_add, BME280_CTRL_HUM , (_hum_sample & 0x07) ); sensor.write_reg(BME280_add, BME280_CTRL_MEAS, (_press_sample & 0x1C) | (_temp_sample & 0xE0) | (_mode & 0x03) ); sensor.write_reg(BME280_add, BME280_CONFIG , (_stanby & 0xE0) | (_filter & 0x1C) ); }