My trial of BME280 library, tested with Adafruit BME280 module
Diff: BME280.cpp
- Revision:
- 0:5ace1cc7a9f2
- Child:
- 1:7b525853bad0
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BME280.cpp Tue May 09 06:32:36 2017 +0000 @@ -0,0 +1,403 @@ +#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); +} \ No newline at end of file