/*************************************************************************** This is a library for the BME280 humidity, temperature & pressure sensor Designed specifically to work with the Adafruit BME280 Breakout ----> http://www.adafruit.com/products/2650 These sensors use I2C or SPI to communicate, 2 or 4 pins are required to interface. Adafruit invests time and resources providing this open source code, please support Adafruit andopen-source hardware by purchasing products from Adafruit! Written by Limor Fried & Kevin Townsend for Adafruit Industries. BSD license, all text above must be included in any redistribution ***************************************************************************/ #include "ch.h" #include "hal.h" #include "bme280.h" #include "pi2c.h" #include bool BME280_isAvailable(uint8_t address) { uint8_t val; if(I2C_read8(address, BME280_REGISTER_CHIPID, &val)) return val == 0x60; else return false; } /** * Initializes BME280 and reads calibration data */ void BME280_Init(bme280_t *handle, uint8_t address) { uint8_t tmp1; uint8_t tmp2; handle->address = address; I2C_read16_LE(address, BME280_REGISTER_DIG_T1, (uint16_t*)&handle->calib.dig_T1); I2C_read16_LE(address, BME280_REGISTER_DIG_T2, (uint16_t*)&handle->calib.dig_T2); I2C_read16_LE(address, BME280_REGISTER_DIG_T3, (uint16_t*)&handle->calib.dig_T3); I2C_read16_LE(address, BME280_REGISTER_DIG_P1, (uint16_t*)&handle->calib.dig_P1); I2C_read16_LE(address, BME280_REGISTER_DIG_P2, (uint16_t*)&handle->calib.dig_P2); I2C_read16_LE(address, BME280_REGISTER_DIG_P3, (uint16_t*)&handle->calib.dig_P3); I2C_read16_LE(address, BME280_REGISTER_DIG_P4, (uint16_t*)&handle->calib.dig_P4); I2C_read16_LE(address, BME280_REGISTER_DIG_P5, (uint16_t*)&handle->calib.dig_P5); I2C_read16_LE(address, BME280_REGISTER_DIG_P6, (uint16_t*)&handle->calib.dig_P6); I2C_read16_LE(address, BME280_REGISTER_DIG_P7, (uint16_t*)&handle->calib.dig_P7); I2C_read16_LE(address, BME280_REGISTER_DIG_P8, (uint16_t*)&handle->calib.dig_P8); I2C_read16_LE(address, BME280_REGISTER_DIG_P9, (uint16_t*)&handle->calib.dig_P9); I2C_read8(address, BME280_REGISTER_DIG_H1, &handle->calib.dig_H1); I2C_read16_LE(address, BME280_REGISTER_DIG_H2, (uint16_t*)&handle->calib.dig_H2); I2C_read8(address, BME280_REGISTER_DIG_H3, &handle->calib.dig_H3); I2C_read8(address, BME280_REGISTER_DIG_H4, &tmp1); I2C_read8(address, BME280_REGISTER_DIG_H5, &tmp2); handle->calib.dig_H4 = (((int8_t)tmp1) << 4) | (tmp2 & 0x0F); I2C_read8(address, BME280_REGISTER_DIG_H6, &tmp1); I2C_read8(address, BME280_REGISTER_DIG_H5, &tmp2); handle->calib.dig_H5 = (((int8_t)tmp1) << 4) | (tmp2 >> 4 & 0x0F); I2C_read8(address, BME280_REGISTER_DIG_H6, (uint8_t*)&handle->calib.dig_H6); I2C_write8(address, BME280_REGISTER_CONTROLHUMID, 0x03); // Set before CONTROL (DS 5.4.3) I2C_write8(address, BME280_REGISTER_CONTROL, 0x3F); chThdSleepMilliseconds(50); // Wait for BME280 BME280_getTemperature(handle); // Set t_fine } /** * Reads the temperature * @return Temperature in degC * 100 */ int16_t BME280_getTemperature(bme280_t *handle) { int32_t var1, var2, adc_T; uint16_t tmp; I2C_read16(handle->address, BME280_REGISTER_TEMPDATA, &tmp); adc_T = tmp; I2C_read8(handle->address, BME280_REGISTER_TEMPDATA+2, (uint8_t*)&tmp); adc_T <<= 8; adc_T |= tmp & 0xFF; adc_T >>= 4; var1 = ((((adc_T>>3) - ((int32_t)handle->calib.dig_T1 <<1))) * ((int32_t)handle->calib.dig_T2)) >> 11; var2 = (((((adc_T>>4) - ((int32_t)handle->calib.dig_T1)) * ((adc_T>>4) - ((int32_t)handle->calib.dig_T1))) >> 12) * ((int32_t)handle->calib.dig_T3)) >> 14; handle->t_fine = var1 + var2; return (handle->t_fine * 5 + 128) >> 8; } /** * Reads the barometric pressure * @param Values to be sampled * @return Pressure in Pa * 10 */ uint32_t BME280_getPressure(bme280_t *handle, uint16_t means) { int64_t var1, var2, p; uint16_t tmp; uint64_t sum = 0; for(uint16_t i=0; iaddress, BME280_REGISTER_PRESSUREDATA, &tmp); adc_P = tmp; I2C_read8(handle->address, BME280_REGISTER_PRESSUREDATA+2, (uint8_t*)&tmp); adc_P <<= 8; adc_P |= tmp & 0xFF; adc_P >>= 4; var1 = ((int64_t)handle->t_fine) - 128000; var2 = var1 * var1 * (int64_t)handle->calib.dig_P6; var2 = var2 + ((var1*(int64_t)handle->calib.dig_P5)<<17); var2 = var2 + (((int64_t)handle->calib.dig_P4)<<35); var1 = ((var1 * var1 * (int64_t)handle->calib.dig_P3)>>8) + ((var1 * (int64_t)handle->calib.dig_P2)<<12); var1 = (((((int64_t)1)<<47)+var1))*((int64_t)handle->calib.dig_P1)>>33; if (var1 == 0) return 0; // avoid exception caused by division by zero p = 1048576 - adc_P; p = (((p<<31) - var2)*3125) / var1; var1 = (((int64_t)handle->calib.dig_P9) * (p>>13) * (p>>13)) >> 25; var2 = (((int64_t)handle->calib.dig_P8) * p) >> 19; sum += ((p + var1 + var2) >> 8) + (((int64_t)handle->calib.dig_P7)<<4); } return sum/(means*26); } /** * Reads the relative humidity * @return rel. humidity in % * 10 */ uint16_t BME280_getHumidity(bme280_t *handle) { int32_t adc_H; uint16_t tmp; I2C_read16(handle->address, BME280_REGISTER_HUMIDDATA, &tmp); adc_H = tmp; int32_t v_x1_u32r; v_x1_u32r = (handle->t_fine - ((int32_t)76800)); v_x1_u32r = (((((adc_H << 14) - (((int32_t)handle->calib.dig_H4) << 20) - (((int32_t)handle->calib.dig_H5) * v_x1_u32r)) + ((int32_t)16384)) >> 15) * (((((((v_x1_u32r * ((int32_t)handle->calib.dig_H6)) >> 10) * (((v_x1_u32r * ((int32_t)handle->calib.dig_H3)) >> 11) + ((int32_t)32768))) >> 10) + ((int32_t)2097152)) * ((int32_t)handle->calib.dig_H2) + 8192) >> 14)); v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((int32_t)handle->calib.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; float h = (v_x1_u32r>>12); return h / 102; } /** * Calculates the altitude (in meters) from the specified atmospheric * pressure (in Pa*10), and sea-level pressure (in Pa). * @param seaLevel Sea-level pressure in Pa * @param atmospheric Airpressure in Pa*10 * @return altitude in cm */ int32_t BME280_getAltitude(uint32_t seaLevel, uint32_t atmospheric) { return (1.0-pow((float)atmospheric/(float)(seaLevel*10), 1.0/5.255)) * 288150000 / 65; }