BME280 Adafruit sensor with Mbed-os compatibility.
Fork of BME280 by
BME280.cpp
- Committer:
- Rhyme
- Date:
- 2017-05-09
- Revision:
- 0:5ace1cc7a9f2
- Child:
- 1:7b525853bad0
File content as of revision 0:5ace1cc7a9f2:
#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 /* * 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] */ 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 << 3) /* pres oversample x4 */ | (0x00) /* Sleep Mode */ ; writeRegs(data, 2) ; readRegs(REG_CTRL_MEAS, data, 1) ; printf("ctrl_meas: 0x%02X\n", data[0]) ; 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, 3) ; dig_H2 = (data[1] << 8) | data[0] ; dig_H3 = data[2] ; // printf("dig_H1:0x%04X, dig_H2:0x%04X, dig_H3:0x%04X\n",dig_H1, dig_H2, dig_H3) ; } 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) ; #if 0 #if defined (TARGET_KL25Z) *((uint8_t *)0x40076000) |= 0x01 ; /* lsb first */ #endif #endif 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++ ) { // m_spi->write((addr+i)|0x80) ; // spacify address to read 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++ ) { // printf("writing 0x%02X := 0x%02X\n", (data[0]+i)^0x80, data[i+1]) ; 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 */ ; // data[1] = 0x38 | 0x02 ; 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]) ; } void BME280::readData(uint8_t data[]) { readRegs(REG_PRESS_MSB, data, 8) ; printf("Data Read: ") ; for(int i = 0 ; i < 8 ; i++ ) { printf("%02X ", data[i]) ; } printf("\n") ; } float BME280::getTemperature(uint8_t data[]) { uint32_t temp_raw; float tempf; // uint8_t data[3]; // readRegs(REG_TEMP_MSB, data, 3) ; temp_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 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 BME280::getHumidity(uint8_t data[]) { uint32_t hum_raw; float humf; // uint8_t data[2]; // readRegs(REG_HUM_MSB, data, 2) ; hum_raw = (data[0] << 8) | data[1]; 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); } float BME280::getPressure(uint8_t data[]) { uint32_t press_raw; float pressf; // uint8_t data[3]; // readRegs(REG_PRESS_MSB, data, 3) ; press_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 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); }