Jens Schneider
/
BME280
Important changes to repositories hosted on mbed.com
Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.
To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.
It is also possible to export all your personal repositories from the account settings page.
Embed:
(wiki syntax)
Show/hide line numbers
BME280.h
00001 /***************************************************************************** 00002 * * 00003 * BOSCH BME208 Temperature Pressure Humidity Sensor Driver / I2C * 00004 * * 00005 * (c) 2015 Jens Schneider * 00006 * mailto:jens.schneider@kaust.edu.sa * 00007 * Visual Computing Center (VCC) * 00008 * King Abdullah University of Science and Technology (KAUST) * 00009 * 4700 Thuwal, Kingdom of Saudi Arabia * 00010 * * 00011 * PERMISSION GRANTED TO USE IN NON-COMMERCIAL AND EDUCATIONAL PROJECTS * 00012 * NO RESPONSIBILITY ASSUMED FOR DAMAGE OR LOSS OF ANY HARDWARE OR SOFTWARE * 00013 * * 00014 * version 0.1 * 00015 * last change 07.Nov.2015 * 00016 * * 00017 *****************************************************************************/ 00018 #ifndef __BME280_H__ 00019 #define __BME280_H__ 00020 00021 #include"mbed.h" 00022 #include<string> 00023 00024 class BME280 { 00025 public: 00026 /// Oversampling settings for Pressure, Temperature, Humidity 00027 enum sampling_t { 00028 SAMPLING_0x = 0x00, ///< skipped, output set to 0x80000 00029 SAMPLING_1x = 0x01, ///< oversampling x1 00030 SAMPLING_2x = 0x02, ///< oversampling x2 00031 SAMPLING_4x = 0x03, ///< oversampling x4 00032 SAMPLING_8x = 0x04, ///< oversampling x8 00033 SAMPLING_16x = 0x05 ///< oversampling x16 00034 }; 00035 /// Standby times for auto mode, ignored in forced mode 00036 enum standby_t { 00037 STANDBY_0_5 = 0x0, ///< 0.5ms standby between autonomous measurements 00038 STANDBY_62_5 = 0x1, ///< 62.5ms standby time 00039 STANDBY_125 = 0x2, ///< 125.0ms standby time 00040 STANDBY_250 = 0x3, ///< 250.0ms standby time 00041 STANDBY_500 = 0x4, ///< 500.0ms standby time 00042 STANDBY_1000 = 0x5, ///< 1000.0ms standby time 00043 STANDBY_10 = 0x6, ///< 10.0ms standby time 00044 STANDBY_20 = 0x7 ///< 20.0ms standby time 00045 }; 00046 /// Filter settings 00047 enum filter_t { 00048 FILTER_OFF = 0x0, ///< no IIR filtering, immediately reaches 75% of step response 00049 FILTER_2 = 0x1, ///< 75% of step response reached after 2 samples 00050 FILTER_4 = 0x2, ///< 75% of step response reached after 5 samples 00051 FILTER_8 = 0x3, ///< 75% of step response reached after 11 samples 00052 FILTER_16 = 0x4 ///< 75% of step response reached after 22 samples 00053 }; 00054 /// Sensor mode 00055 enum mode_t { 00056 MODE_SLEEP = 0x00, ///< sleep mode, can be achieved by calling reset() 00057 MODE_FORCED = 0x01, ///< forced mode, conversion only upon request 00058 MODE_AUTO = 0x03 ///< continuous measurement mode 00059 }; 00060 /// Registers 00061 static const uint8_t REG_HUM_LSB; ///< Humidity, lsb register 00062 static const uint8_t REG_HUM_MSB; ///< Humidity, msb register 00063 static const uint8_t REG_TEMP_XLSB; ///< Temperature, xlsb register (4bit) 00064 static const uint8_t REG_TEMP_LSB; ///< Temperature, lsb register 00065 static const uint8_t REG_TEMP_MSB; ///< Temperature, msb register 00066 static const uint8_t REG_PRESS_XLSB; ///< Pressure, xlsb register (4bit) 00067 static const uint8_t REG_PRESS_LSB; ///< Pressure, lsb register 00068 static const uint8_t REG_PRESS_MSB; ///< Pressure, msb register 00069 static const uint8_t REG_CONFIG; ///< Config register 00070 static const uint8_t REG_CTRL_MEAS; ///< Control Measurement register 00071 static const uint8_t REG_STATUS; ///< Status register 00072 static const uint8_t REG_CTRL_HUM; ///< Control Humidity register 00073 static const uint8_t REG_CALIB26_41_BASE; ///< Base of higher calibration data registers 00074 static const uint8_t REG_RESET; ///< Soft Reset register 00075 static const uint8_t REG_ID; ///< Chip ID register 00076 static const uint8_t REG_CALIB00_25_BASE; ///< Base of lower calibration data registers 00077 /// Values 00078 static const uint8_t VAL_CALIB26_41_SIZE; ///< Amount of higher calibration data 00079 static const uint8_t VAL_CALIB00_25_SIZE; ///< Amount of lower calibration data 00080 static const uint8_t VAL_CHIP_ID; ///< Chip ID 00081 static const uint8_t VAL_RESET; ///< Reset command 00082 static const uint8_t STATUS_IDLE; ///< Status value for Idle 00083 static const uint8_t STATUS_MEASURING; ///< Status value for Measurment in progress 00084 static const uint8_t STATUS_UPDATING; ///< Status value for Updating calibration registers from NVM 00085 static const uint8_t STATUS_ERROR; ///< Status value for Error 00086 00087 protected: 00088 00089 /// Calibration data structure 00090 struct calib_t { 00091 uint16_t dig_T1; 00092 int16_t dig_T2; 00093 int16_t dig_T3; 00094 uint16_t dig_P1; 00095 int16_t dig_P2; 00096 int16_t dig_P3; 00097 int16_t dig_P4; 00098 int16_t dig_P5; 00099 int16_t dig_P6; 00100 int16_t dig_P7; 00101 int16_t dig_P8; 00102 int16_t dig_P9; 00103 uint8_t dig_H1; 00104 int16_t dig_H2; 00105 uint8_t dig_H3; 00106 int16_t dig_H4; 00107 int16_t dig_H5; 00108 int8_t dig_H6; 00109 } m_calib; 00110 00111 public: 00112 00113 BME280(void); ///< Default constructor 00114 ~BME280(void); ///< Destructor 00115 bool init(I2C& i2c, uint8_t address=0x76); ///< Initialize sensor and read out calibration 00116 bool start( sampling_t hum = SAMPLING_8x, ///< Start measurement with provided configuration 00117 sampling_t temp = SAMPLING_8x, 00118 sampling_t press = SAMPLING_8x, 00119 standby_t standby = STANDBY_500, 00120 filter_t filter = FILTER_8, 00121 mode_t mode = MODE_AUTO); 00122 bool stop(void); ///< Stop measurement and put sensor in sleep mode 00123 bool done(void); ///< "Detach" sensor from I2C bus and put in sleep mode 00124 bool get(float& T, float& P, float& H); ///< read float data: [T]=1C [P]=1 hPa [H]=% 00125 bool get(int32_t& T,uint32_t& P,uint32_t& H); ///< read int data: [T]=0.01C [P]=1/256 Pa [H]=1/1024 % 00126 const bool& is_ok(void) const; ///< true iff sensor initialized properly 00127 const std::string& name(void) const; ///< returns sensor name 00128 00129 /// LOW LEVEL API 00130 uint8_t read_chip_id(void); ///< returns the chip id on success, 0x00 on failure 00131 bool reset(void); ///< reset the sensor and put to sleep mode 00132 uint8_t read_status(void); ///< read status, returns 0xFF on failure 00133 bool write8(uint8_t reg,uint8_t val); ///< write 8bit register, returns true on success 00134 bool read8(uint8_t reg,uint8_t& val); ///< read 8bit register, returns true on success 00135 const calib_t& calib(void) const; ///< access to calibration data 00136 bool burst_read(uint8_t* data, uint8_t nBytes, 00137 uint8_t reg); ///< burst read of data 00138 00139 I2C* m_pI2C; ///< pointer to I2C bus 00140 uint8_t m_address; ///< slave address (with write flag) 00141 int32_t m_fine_temp; ///< last temperature for thermo-compensation 00142 mode_t m_mode; ///< sensor mode 00143 bool m_bOk; ///< sensor initialized ok? 00144 00145 bool read_calibration(void); ///< read lower and higher part of calibration data 00146 bool read_calibration_lo(void); ///< read lower part of calibration data 00147 bool read_calibration_hi(void); ///< read higher part of calibration data 00148 int16_t conv_s16(const uint8_t* data, ///< convert 2 bytes of calibration data to int16 00149 int lo, int hi) const; 00150 uint16_t conv_u16(const uint8_t* data, ///< convert 2 bytes of calibration data to uint16 00151 int lo, int hi) const; 00152 bool raw_data(int32_t& T,int32_t& P,int32_t& H); ///< read the raw sensor data 00153 00154 /// converts a raw temperature measurement into degree C, resolution 0.01C 00155 /// updates m_fine_temp for later pressure and humidity compensation 00156 int32_t compensate_T(int32_t raw_T); 00157 00158 /// converts a raw pressure measurement into PA, resolution 1/256 Pa / 1/256000 hPa 00159 /// uses m_fine_temp for correction 00160 uint32_t compensate_P(int32_t raw_P); 00161 00162 // converts a raw humidity measurement into %rel.H., resolution 1/1024 % rh 00163 // uses m_fine_temp for correction 00164 uint32_t compensate_H(int32_t raw_H); 00165 static const std::string m_name; 00166 private: 00167 // No copy constructor for you! 00168 BME280(const BME280& other); 00169 }; 00170 00171 #endif
Generated on Wed Jul 13 2022 19:37:59 by
1.7.2