/* Copyright 2021 rate * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <stdint.h> #include "bme280.h" #include "i2c_master.h" #define BME280_ADDRESS (0x76<<1) #define BME280_REG_CALIB00 (0x88) #define BME280_REG_CALIB25 (0xA1) #define BME280_REG_CALIB26 (0xE1) #define BME280_REG_CTRL_HUM (0xF2) #define BME280_REG_CTRL_MEAS (0xF4) #define BME280_REG_CONFIG (0xF5) #define BME280_REG_PRESS_MSB (0xf7) #define I2C_BME280_TIMEOUT (20) /* BME280 configurator values */ /* [2:0] Humidity oversampling * 000 Skipped * 001 oversampling x1 * 010 oversampling x2 * 011 oversampling x4 * 100 oversampling x8 * 101,others oversampling x16 */ #define BME280_CTRL_HUM_VAL (0x01) /* [7:5] Pressure oversampling * 000 Skipped * 001 oversampling x1 * 010 oversampling x2 * 011 oversampling x4 * 100 oversampling x8 * 101,others oversampling x16 * [4:2] Temperature oversampling * 000 Skipped * 001 oversampling x1 * 010 oversampling x2 * 011 oversampling x4 * 100 oversampling x8 * 101,others oversampling x16 * [1:0] Mode * 00 Sleep mode * 11 Normal mode */ #define BME280_CTRL_MEAS_VAL (0x27) /* [7:5] t_standby[ms] * 000 0.5 * 001 62.5 * 010 125 * 011 250 * 100 500 * 101 1000 * 110 10 * 111 20 * [4:2] Filter corefficient * 000 Filter off * 001 2 * 010 4 * 011 8 * 100,others 16 * [0] SPI interface * 0 4-wire * 1 3-wire */ #define BME280_CONFIG_VAL (0xA0) static void readTrim(void); static void readData(void); static int32_t calibration_T(int32_t adc_T); static uint32_t calibration_P(int32_t adc_P); static uint32_t calibration_H(int32_t adc_H); static uint32_t hum_raw,temp_raw,pres_raw; static uint16_t dig_T1; static int16_t dig_T2, dig_T3; static uint16_t dig_P1; static int16_t dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9; static uint8_t dig_H1, dig_H3; static int16_t dig_H2, dig_H4, dig_H5; static int8_t dig_H6; static int32_t t_fine; /* Private */ static void readTrim(void) { uint8_t data[32]; i2c_readReg(BME280_ADDRESS, BME280_REG_CALIB00, &data[0], 24, I2C_BME280_TIMEOUT); i2c_readReg(BME280_ADDRESS, BME280_REG_CALIB25, &data[25], 1, I2C_BME280_TIMEOUT); i2c_readReg(BME280_ADDRESS, BME280_REG_CALIB26, &data[25], 7, I2C_BME280_TIMEOUT); dig_T1 = (data[1] << 8) | data[0]; dig_T2 = (data[3] << 8) | data[2]; dig_T3 = (data[5] << 8) | data[4]; dig_P1 = (data[7] << 8) | data[6]; dig_P2 = (data[9] << 8) | data[8]; dig_P3 = (data[11]<< 8) | data[10]; dig_P4 = (data[13]<< 8) | data[12]; dig_P5 = (data[15]<< 8) | data[14]; dig_P6 = (data[17]<< 8) | data[16]; dig_P7 = (data[19]<< 8) | data[18]; dig_P8 = (data[21]<< 8) | data[20]; dig_P9 = (data[23]<< 8) | data[22]; dig_H1 = data[24]; dig_H2 = (data[26]<< 8) | data[25]; dig_H3 = data[27]; dig_H4 = (data[28]<< 4) | (0x0F & data[29]); dig_H5 = (data[30] << 4) | ((data[29] >> 4) & 0x0F); dig_H6 = data[31]; return; } static void readData(void) { uint8_t data[8]; i2c_readReg(BME280_ADDRESS, 0xF7, &data[0], 8, I2C_BME280_TIMEOUT); pres_raw = data[0]; pres_raw = (pres_raw<<8) | data[1]; pres_raw = (pres_raw<<4) | (data[2] >> 4); temp_raw = data[3]; temp_raw = (temp_raw<<8) | data[4]; temp_raw = (temp_raw<<4) | (data[5] >> 4); hum_raw = data[6]; hum_raw = (hum_raw << 8) | data[7]; return; } static int32_t calibration_T(int32_t adc_T) { int32_t var1, var2, T; var1 = ((((adc_T >> 3) - ((int32_t)dig_T1<<1))) * ((int32_t)dig_T2)) >> 11; var2 = (((((adc_T >> 4) - ((int32_t)dig_T1)) * ((adc_T>>4) - ((int32_t)dig_T1))) >> 12) * ((int32_t)dig_T3)) >> 14; t_fine = var1 + var2; T = (t_fine * 5 + 128) >> 8; return T; } static uint32_t calibration_P(int32_t adc_P) { int32_t var1, var2; uint32_t P; var1 = (((int32_t)t_fine)>>1) - (int32_t)64000; var2 = (((var1>>2) * (var1>>2)) >> 11) * ((int32_t)dig_P6); var2 = var2 + ((var1*((int32_t)dig_P5))<<1); var2 = (var2>>2)+(((int32_t)dig_P4)<<16); var1 = (((dig_P3 * (((var1>>2)*(var1>>2)) >> 13)) >>3) + ((((int32_t)dig_P2) * var1)>>1))>>18; var1 = ((((32768+var1))*((int32_t)dig_P1))>>15); if (var1 == 0) { return 0; } P = (((uint32_t)(((int32_t)1048576)-adc_P)-(var2>>12)))*3125; if( P < 0x80000000 ) { P = (P << 1) / ((uint32_t) var1); } else { P = (P / (uint32_t)var1) * 2; } var1 = (((int32_t)dig_P9) * ((int32_t)(((P>>3) * (P>>3))>>13)))>>12; var2 = (((int32_t)(P>>2)) * ((int32_t)dig_P8))>>13; P = (uint32_t)((int32_t)P + ((var1 + var2 + dig_P7) >> 4)); return P; } static uint32_t calibration_H(int32_t adc_H) { int32_t v_x1; v_x1 = (t_fine - ((int32_t)76800)); v_x1 = (((((adc_H << 14) -(((int32_t)dig_H4) << 20) - (((int32_t)dig_H5) * v_x1)) + ((int32_t)16384)) >> 15) * (((((((v_x1 * ((int32_t)dig_H6)) >> 10) * (((v_x1 * ((int32_t)dig_H3)) >> 11) + ((int32_t) 32768))) >> 10) + (( int32_t)2097152)) * ((int32_t) dig_H2) + 8192) >> 14)); v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * ((int32_t)dig_H1)) >> 4)); v_x1 = (v_x1 < 0 ? 0 : v_x1); v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1); return (uint32_t)(v_x1 >> 12); } /* Public */ void bme280_init(void) { uint8_t ctrl_hum_reg; uint8_t ctrl_meas_reg; uint8_t config_reg; ctrl_hum_reg = BME280_CTRL_HUM_VAL; ctrl_meas_reg = BME280_CTRL_MEAS_VAL; config_reg = BME280_CONFIG_VAL; i2c_init(); i2c_writeReg(BME280_ADDRESS, BME280_REG_CTRL_HUM, &ctrl_hum_reg, 1, I2C_BME280_TIMEOUT); i2c_writeReg(BME280_ADDRESS, BME280_REG_CTRL_MEAS, &ctrl_meas_reg, 1, I2C_BME280_TIMEOUT); i2c_writeReg(BME280_ADDRESS, BME280_REG_CONFIG, &config_reg, 1, I2C_BME280_TIMEOUT); readTrim(); return; } void bme280_exec(void) { readData(); return; } double bme280_getTemp(void) { double temp_act; int32_t temp_cal; temp_cal = calibration_T(temp_raw); temp_act = (double)temp_cal / 100.0; return temp_act; } double bme280_getPress(void) { double press_act; uint32_t press_cal; press_cal = calibration_P(pres_raw); press_act = (double)press_cal / 100.0; return press_act; } double bme280_getHum(void) { double hum_act; uint32_t hum_cal; hum_cal = calibration_H(hum_raw); hum_act = (double)hum_cal / 1024.0; return hum_act; }