pulga+gps
Dependencies: pulga-lorawan-drv SPI_MX25R Si1133 BME280
Diff: BME280.txt
- Revision:
- 61:65744bc8ab55
diff -r c4f9e9202fb4 -r 65744bc8ab55 BME280.txt --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BME280.txt Fri Jan 08 20:16:58 2021 +0000 @@ -0,0 +1,189 @@ +#include "mbed.h" +#define _DEBUG + +I2C sensor(p13, p15); + +#ifdef _DEBUG +#define DEBUG_PRINT(...) printf(__VA_ARGS__) +#else +#define DEBUG_PRINT(...) +#endif + +const int BME280_ADDR = (0x77 << 1); + +uint16_t dig_T1; +int16_t dig_T2, dig_T3; +uint16_t dig_P1; +int16_t dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9; +uint16_t dig_H1, dig_H3; +int16_t dig_H2, dig_H4, dig_H5, dig_H6; +int32_t t_fine; + +void init() +{ + char cmd[18]; + + sensor.frequency(1000000); + + cmd[0] = 0xf2; // ctrl_hum + cmd[1] = 0x01; + sensor.write(BME280_ADDR, cmd, 2); + + cmd[0] = 0xf4; // ctrl_meas + cmd[1] = 0x27; + sensor.write(BME280_ADDR, cmd, 2); + + cmd[0] = 0xf5; // config + cmd[1] = 0xa0; + sensor.write(BME280_ADDR, cmd, 2); + + cmd[0] = 0x88; // read dig_T regs + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, cmd, 6); + + dig_T1 = (cmd[1] << 8) | cmd[0]; + dig_T2 = (cmd[3] << 8) | cmd[2]; + dig_T3 = (cmd[5] << 8) | cmd[4]; + +// DEBUG_PRINT("dig_T = 0x%x, 0x%x, 0x%x\n", dig_T1, dig_T2, dig_T3); + + cmd[0] = 0x8E; // read dig_P regs + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, cmd, 18); + + dig_P1 = (cmd[ 1] << 8) | cmd[ 0]; + dig_P2 = (cmd[ 3] << 8) | cmd[ 2]; + dig_P3 = (cmd[ 5] << 8) | cmd[ 4]; + dig_P4 = (cmd[ 7] << 8) | cmd[ 6]; + dig_P5 = (cmd[ 9] << 8) | cmd[ 8]; + dig_P6 = (cmd[11] << 8) | cmd[10]; + dig_P7 = (cmd[13] << 8) | cmd[12]; + dig_P8 = (cmd[15] << 8) | cmd[14]; + dig_P9 = (cmd[17] << 8) | cmd[16]; + +// DEBUG_PRINT("dig_P = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_P1, dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9); + + cmd[0] = 0xA1; // read dig_H regs + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, cmd, 9); + + dig_H1 = cmd[0]; + dig_H2 = (cmd[2] << 8) | cmd[1]; + dig_H3 = cmd[3]; + dig_H4 = (cmd[4] << 4) | (cmd[5] & 0x0f); + dig_H5 = (cmd[7] << 4) | ((cmd[6]>>4) & 0x0f); + dig_H6 = cmd[8]; + +// DEBUG_PRINT("dig_H = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_H1, dig_H2, dig_H3, dig_H4, dig_H5, dig_H6); +} + +float getTemperature() +{ + uint32_t temp_raw; + float tempf; + char cmd[4]; + + cmd[0] = 0xfa; // temp_msb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[1], 1); + + cmd[0] = 0xfb; // temp_lsb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[2], 1); + + cmd[0] = 0xfc; // temp_xlsb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[3], 1); + + temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4); + + int32_t temp; + + temp = + (((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11) + + ((((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12) * dig_T3) >> 14); + + t_fine = temp; + temp = (temp * 5 + 128) >> 8; + tempf = (float)temp; + + return (tempf/100.0f); +} + +float getPressure() +{ + uint32_t press_raw; + float pressf; + char cmd[4]; + + cmd[0] = 0xf7; // press_msb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[1], 1); + + cmd[0] = 0xf8; // press_lsb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[2], 1); + + cmd[0] = 0xf9; // press_xlsb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[3], 1); + + press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4); + + int32_t var1, var2; + uint32_t press; + + var1 = (t_fine >> 1) - 64000; + var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * dig_P6; + var2 = var2 + ((var1 * dig_P5) << 1); + var2 = (var2 >> 2) + (dig_P4 << 16); + var1 = (((dig_P3 * (((var1 >> 2)*(var1 >> 2)) >> 13)) >> 3) + ((dig_P2 * var1) >> 1)) >> 18; + var1 = ((32768 + var1) * dig_P1) >> 15; + if (var1 == 0) { + return 0; + } + press = (((1048576 - press_raw) - (var2 >> 12))) * 3125; + if(press < 0x80000000) { + press = (press << 1) / var1; + } else { + press = (press / var1) * 2; + } + var1 = ((int32_t)dig_P9 * ((int32_t)(((press >> 3) * (press >> 3)) >> 13))) >> 12; + var2 = (((int32_t)(press >> 2)) * (int32_t)dig_P8) >> 13; + press = (press + ((var1 + var2 + dig_P7) >> 4)); + + pressf = (float)press; + return (pressf/100.0f); +} + +float getHumidity() +{ + uint32_t hum_raw; + float humf; + char cmd[4]; + + cmd[0] = 0xfd; // hum_msb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[1], 1); + + cmd[0] = 0xfd; // hum_lsb + sensor.write(BME280_ADDR, cmd, 1); + sensor.read(BME280_ADDR, &cmd[2], 1); + + hum_raw = (cmd[1] << 8) | cmd[2]; + + int32_t v_x1; + + v_x1 = t_fine - 76800; + v_x1 = (((((hum_raw << 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) + 32768)) >> 10) + 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); + + humf = (float)(v_x1 >> 12); + + return (humf/1024.0f); +}