BME280 Adafruit sensor with Mbed-os compatibility.
Fork of BME280 by
BME280.cpp
- Committer:
- Rhyme
- Date:
- 2017-05-10
- Revision:
- 1:7b525853bad0
- Parent:
- 0:5ace1cc7a9f2
- Child:
- 2:ee200b715195
File content as of revision 1:7b525853bad0:
#include "mbed.h" #include "BME280.h" /* internal registers */ #define REG_HUM_LSB 0xFE #define REG_HUM_MSB 0xFD #define REG_TEMP_XLSB 0xFC #define REG_TEMP_LSB 0xFB #define REG_TEMP_MSB 0xFA #define REG_PRESS_XLSB 0xF9 #define REG_PRESS_LSB 0xF8 #define REG_PRESS_MSB 0xF7 #define REG_CONFIG 0xF5 #define REG_CTRL_MEAS 0xF4 #define REG_STATUS 0xF3 #define REG_CTRL_HUM 0xF2 #define REG_RESET 0xE0 #define REG_ID 0xD0 #define REG_CALIB00 0x88 #define REG_CALIB25 0xA1 #define REG_CALIB26 0xE1 #define REG_CALIB41 0xF0 /** Trimming parameters */ /* temperature */ #define REG_T1_LSB 0x88 #define REG_T1_MSB 0x89 #define REG_T2_LSB 0x8A #define REG_T2_MSB 0x8B #define REG_T3_LSB 0x8C #define REG_T3_MSB 0x8D /* pressure */ #define REG_P1_LSB 0x8E #define REG_P1_MSB 0x8F #define REG_P2_LSB 0x90 #define REG_P2_MSB 0x91 #define REG_P3_LSB 0x92 #define REG_P3_MSB 0x93 #define REG_P4_LSB 0x94 #define REG_P4_MSB 0x95 #define REG_P5_LSB 0x96 #define REG_P5_MSB 0x97 #define REG_P6_LSB 0x98 #define REG_P6_MSB 0x99 #define REG_P7_LSB 0x9A #define REG_P7_MSB 0x9B #define REG_P8_LSB 0x9C #define REG_P8_MSB 0x9D #define REG_P9_LSB 0x9E #define REG_P9_MSB 0x9F /* humidity */ #define REG_H1 0xA1 #define REG_H2_LSB 0xE1 #define REG_H2_MSB 0xE2 #define REG_H3 0xE3 #define REG_H4 0xE4 #define REG_H5 0xE5 #define REG_H6 0xE7 /* * Register description * 0xD0 "id" * chip identification number chip_id[7:0], which is 0x60 * * 0xE0 "reset" * Software reset register, writing 0xB6 causes complete power-on-reset. * * 0xF2 "ctrl_hum" * Specifies the humidity data acquision options. * Note: Changes to this register only become effective after a write * operaion to "ctrl_meas". * bit[2:0] osrs_h[2:0] Controls oversampling of humidity data. * 000: Skipped (output set to 0x8000) * 001: oversampling x1 * 010: oversampling x2 * 011: oversampling x4 * 100: oversampling x8 * 101, others, oversampling x16 * * 0xF3 "status" * bit[3] measuring[0] Automatically set to '1' during conversion * and back to '0' when done * bit[0] im_update[0] Automatically set to '1' during NVM data copy * and back to '0' when done * * 0xF4 "ctrl_meas" * Specifies the pressure and temperature data acquision options. * Note: This register needs to be written after canging "ctrl_hum" to take effect. * bit[7:5] osrs_t[2:0] Controls oversampling of temperature data * bit value is similar to osrs_h (except 000 output set to 0x80000) * bit[4:2] osrs_p[2:0] Controls oversampling of pressure data * bit value is similar to osrs_h (except 000 output set to 0x80000) * bit[1:0] mode[1:0] Controls the sensor mode. * 00: Sleep mode * 01: Forced mode * 10: Forced mode * 11: Normal mode * * 0xF5 "config" * Specifies the rate, filter and interface options. * Writes to "config" in normal mode may be ignored. * In sleep mode writes are not ignored. * bit[7:5] t_sb[2:0] Controls inactive duration t_standby in normal mode. * 000: 0.5 [ms] * 001: 62.5 [ms] * 010: 125 [ms] * 011: 250 [ms] * 100: 500 [ms] * 101: 1000 [ms] * 110: 10 [ms] * 111: 20 [ms] * bit[4:2] filter[2:0] Controls the time constant of the IIR filter. * 000: Filter off * 001: 2 * 010: 4 * 011: 8 * 100, others: 16 * * 0xF7 .. 0xF9 "press" (_msb, _lsb, _xlsb) * 0xF7 bit[7:0] press_msb[7:0] MSB part up[19:12] * 0xF8 bit[7:0] press_lsb[7:0] LSB part up[11:4] * 0xF9 bit[7:4] press_xlsb[3:0] XLSB part up[3:0] * * 0xFA .. 0xFC "temp" (_msb, _lsb, _xlsb) * 0xFA bit[7:0] temp_msb[7:0] MSB part ut[19:12] * 0xFB bit[7:0] temp_lsb[7:0] LSB part ut[11:4] * 0xFC bit[7:4] temp_xlsp[3:0] XLSB part ut[3:0] * * 0xFD .. 0xFE "hum" (_msb, _lsb) * 0xFD bit[7:0] hum_msb[7:0] MSB part uh[15:8] * 0xFE bit[7:0] hum_lsb[7:0] LSB part uh[7:0] */ /* * Compensation parameter storage, naming and data type * Register addr, Register content, Data type * 0x88/0x89, dig_T1[7:0]/[15:8], unsigned short * 0x8A/0x8B, dig_T2[7:0]/[15:8], signed short * 0x8C/0x8D, dig_T3[7:0]/[15:8], signed short * 0x8E/0x8F, dig_P1[7:0]/[15:8], unsigned short * 0x90/0x91, dig_P2[7:0]/[15:8], signed short * 0x92/0x93, dig_P3[7:0]/[15:8], signed short * 0x94/0x95, dig_P4[7:0]/[15:8], signed short * 0x96/0x97, dig_P5[7:0]/[15:8], signed short * 0x98/0x99, dig_P6[7:0]/[15:8], signed short * 0x9A/0x9B, dig_P7[7:0]/[15:8], signed short * 0x9C/0x9D, dig_P8[7:0]/[15:8], signed short * 0x9E/0x9F, dig_P9[7:0]/[15:8], signed short * 0xA1, dig_H1[7:0], unsigned char * 0xE1/0xE2, dig_H2[7:0]/[15:8], signed short * 0xE3, dig_H3[7:0], unsigned char * 0xE4/0xE5[3:0], dig_H4[11:4]/[3:0] signed short * 0xE5[7:4]/0xE6, dig_H5[3:0]/[11:4] signed short * 0xE7, dig_H6[7:0], signed char */ void BME280::init(void) { uint8_t data[18] ; data[0] = REG_CTRL_HUM ; data[1] = 0x03 ; /* Humidity oversampling x4 */ writeRegs(data, 2) ; data[0] = REG_CTRL_MEAS ; data[1] = (0x3 << 5) /* temp oversample x4 */ | (0x3 << 2) /* pres oversample x4 */ | (0x00) /* Sleep Mode */ ; writeRegs(data, 2) ; data[0] = REG_CONFIG ; data[1] = (0x4 << 5) /* standby 500ms */ | (0x0 << 2) /* filter off */ | (0x0) /* spi 4wire mode */ ; writeRegs(data, 2) ; /* read dig_T regs */ readRegs(REG_T1_LSB, data, 6) ; dig_T1 = (data[1] << 8) | data[0] ; dig_T2 = (data[3] << 8) | data[2] ; dig_T3 = (data[5] << 8) | data[4] ; // printf("dig_T1:0x%04X, dig_T2:0x%04X, dig_T3:0x%04X\n",dig_T1, dig_T2, dig_T3) ; /* read dig_P regs */ readRegs(REG_P1_LSB, data, 18) ; dig_P1 = (data[ 1] << 8) | data[ 0] ; dig_P2 = (data[ 3] << 8) | data[ 2] ; dig_P3 = (data[ 5] << 8) | data[ 4] ; dig_P4 = (data[ 7] << 8) | data[ 6] ; dig_P5 = (data[ 9] << 8) | data[ 8] ; dig_P6 = (data[11] << 8) | data[10] ; dig_P7 = (data[13] << 8) | data[12] ; dig_P8 = (data[15] << 8) | data[14] ; dig_P9 = (data[17] << 8) | data[16] ; // printf("dig_P1:0x%04X, dig_P2:0x%04X, dig_P3:0x%04X\n",dig_P1, dig_P2, dig_P3) ; // printf("dig_P4:0x%04X, dig_P5:0x%04X, dig_P6:0x%04X\n",dig_P4, dig_P5, dig_P6) ; // printf("dig_P7:0x%04X, dig_P8:0x%04X, dig_P9:0x%04X\n",dig_P7, dig_P8, dig_P9) ; /* read dig_H regs */ readRegs(REG_H1, data, 1) ; dig_H1 = data[0] ; readRegs(REG_H2_LSB, data, 2) ; dig_H2 = (data[1] << 8) | data[0] ; readRegs(REG_H3, data, 1) ; dig_H3 = data[0] ; readRegs(REG_H4, data, 3) ; dig_H4 = (data[0] << 4) | (data[1] & 0x0F) ; dig_H5 = (data[2] << 4) | (data[1] >> 4) ; readRegs(REG_H6, data, 1) ; dig_H6 = data[0] ; // printf("dig_H1:0x%04X, dig_H2:0x%04X, dig_H3:0x%04X\n",dig_H1, dig_H2, dig_H3) ; // printf("dig_H4:0x%04X, dig_H5:0x%04X, dig_H6:0x%04X\n",dig_H4, dig_H5, dig_H6) ; trigger() ; /* dummy measure */ } BME280::BME280(PinName sda, PinName scl, int addr) { m_i2c = new I2C(sda, scl) ; m_addr = (addr << 1) ; m_spi = 0 ; m_cs = 0 ; init() ; } BME280::BME280(PinName sck, PinName miso, PinName mosi, PinName cs) { m_cs = new DigitalOut(cs, 1) ; m_spi = new SPI(mosi, miso, sck) ; m_spi->format(8, 3) ; m_i2c = 0 ; m_addr = 0 ; init() ; } BME280::~BME280() { if (m_spi) { delete m_spi ; delete m_cs ; } if (m_i2c) { delete m_i2c ; m_addr = 0 ; } } void BME280::i2c_readRegs(int addr, uint8_t * data, int len) { char t[1] = {addr} ; m_i2c->write(m_addr, t, 1, true) ; m_i2c->read(m_addr, (char*)data, len) ; } void BME280::i2c_writeRegs(uint8_t * data, int len) { m_i2c->write(m_addr, (char *)data, len) ; } void BME280::spi_readRegs(int addr, uint8_t * data, int len) { *m_cs = 0 ; m_spi->write(addr | 0x80) ; for (int i = 0 ; i < len ; i++ ) { data[i] = m_spi->write((addr+i)|0x80) ; } m_spi->write(0x00) ; // to terminate read mode *m_cs = 1 ; } void BME280::spi_writeRegs(uint8_t * data, int len) { *m_cs = 0 ; for (int i = 0 ; i < len-1 ; i++ ) { m_spi->write((data[0]+i)^0x80) ; /* register address */ m_spi->write(data[i+1]) ; /* data to write */ } *m_cs = 1 ; } void BME280::readRegs(int addr, uint8_t *data, int len) { if (m_spi) { spi_readRegs(addr, data, len) ; } else if (m_i2c) { i2c_readRegs(addr, data, len) ; } } void BME280::writeRegs(uint8_t *data, int len) { if (m_spi) { spi_writeRegs(data, len) ; } else if (m_i2c) { i2c_writeRegs(data, len) ; } } void BME280::reset(void) { uint8_t data[2] ; data[0] = REG_RESET ; data[1] = 0xB6 ; writeRegs(data, 2) ; } void BME280::trigger(void) { uint8_t data[2] ; readRegs(REG_CTRL_MEAS, &data[1], 1) ; data[0] = REG_CTRL_MEAS ; data[1] = (data[1] & 0xFC) /* keep oversampling */ | (0x2) /* Forced Mode */ ; writeRegs(data, 2) ; } uint8_t BME280::busy(void) { uint8_t data[1] ; readRegs(REG_STATUS, data, 1) ; return( data[0] & 0x9 ) ; } uint8_t BME280::getID(void) { uint8_t data[1] ; readRegs(REG_ID, data, 1) ; return(data[0]) ; } float BME280::getTemperature(void) { float tempf ; uint8_t data[3] ; BME280_S32_t var1, var2, T ; BME280_S32_t adc_T ; readRegs(REG_TEMP_MSB, data, 3) ; adc_T = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4); var1 = ((((adc_T>>3) - ((BME280_S32_t)dig_T1<<1))) * ((BME280_S32_t)dig_T2)) >> 11; var2 = (((((adc_T>>4) - ((BME280_S32_t)dig_T1)) * ((adc_T>>4) - ((BME280_S32_t)dig_T1))) >> 12) * ((BME280_S32_t)dig_T3)) >> 14; t_fine = var1 + var2; T = (t_fine * 5 + 128) >> 8; tempf = (float)T; return (tempf/100.0f); } float BME280::getPressure(void) { BME280_S32_t adc_P ; BME280_S64_t var1, var2, p ; float pressf; uint8_t data[3]; readRegs(REG_PRESS_MSB, data, 3) ; adc_P = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4); var1 = ((BME280_S64_t)t_fine) - 128000; var2 = var1 * var1 * (BME280_S64_t)dig_P6; var2 = var2 + ((var1*(BME280_S64_t)dig_P5)<<17); var2 = var2 + (((BME280_S64_t)dig_P4)<<35); var1 = ((var1 * var1 * (BME280_S64_t)dig_P3)>>8) + ((var1 * (BME280_S64_t)dig_P2)<<12); var1 = (((((BME280_S64_t)1)<<47)+var1))*((BME280_S64_t)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 = (((BME280_S64_t)dig_P9) * (p>>13) * (p>>13)) >> 25; var2 = (((BME280_S64_t)dig_P8) * p) >> 19; p = ((p + var1 + var2) >> 8) + (((BME280_S64_t)dig_P7)<<4); pressf = (float)(p >> 8) ; return (pressf/100.0f); } float BME280::getHumidity(void) { BME280_S32_t adc_H; BME280_S32_t v_x1_u32r ; float humf; uint8_t data[2]; readRegs(REG_HUM_MSB, data, 2) ; adc_H = (data[0] << 8) | data[1]; v_x1_u32r = (t_fine - ((BME280_S32_t)76800)); v_x1_u32r = (((((adc_H << 14) - (((BME280_S32_t)dig_H4) << 20) - (((BME280_S32_t)dig_H5) * v_x1_u32r)) + ((BME280_S32_t)16384)) >> 15) * (((((((v_x1_u32r * ((BME280_S32_t)dig_H6)) >> 10) * (((v_x1_u32r * ((BME280_S32_t)dig_H3)) >> 11) + ((BME280_S32_t)32768))) >> 10) + ((BME280_S32_t)2097152)) * ((BME280_S32_t)dig_H2) + 8192) >> 14)); v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((BME280_S32_t)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); humf = (float)(v_x1_u32r >> 12) ; return (humf/1024.0f); }