Kevin Braun
Multi environmental sensor
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bme280.h
00001 #ifndef BME280_H 00002 #define BME280_H 00003 00004 #include "mbed.h" 00005 00006 #if(defined(TARGET_KL25Z) || defined(TARGET_K64F)) 00007 00008 // #define BME280i2cLOWLEVEL 1 //if the use of low-level I2C routines is needed 00009 // #warning "BME280 using low level I2C routines" 00010 00011 #endif 00012 00013 00014 #define SEA_PRESS 1013.25 //default sea level pressure level in mb 00015 //#define KNOWNALT 327.0 //default known altitude in feet 00016 #define METERS_FEET 3.2808399 00017 #define FEET_METERS 0.3048006 00018 #define MB_INHG_DOUBLE 0.02952998751 00019 #define INHG_MB_DOUBLE 33.8638815767 00020 #define DEGC_DEGF_FLOAT 9.0 / 5.0 + 32.0 00021 #define DEGC_DEGF_INT 9 / 5 + 32 00022 00023 #define BME280_WADDR 0xEC //i2c address write mode (CSBpin = 0); 00024 #define BME280_RADDR 0xED //i2c address read mode 00025 00026 #define BME280_CHIP_ID_REG 0xD0 //Chip ID Register 00027 #define BME280_CAL_DATA_START_1 0x88 //Calibration data parameters 00028 #define BME280_CAL_DATA_START_2 0xE1 //More calibration data parameters 00029 #define BME280_RST_REG 0xE0 //Softreset Register 00030 #define BME280_STAT_REG 0xF3 //Status Register 00031 #define BME280_CTRL_MEAS_REG 0xF4 //Ctrl Measure Register 00032 #define BME280_CTRL_HUMIDITY_REG 0xF2 //Ctrl Humidity Register 00033 #define BME280_CONFIG_REG 0xF5 //Configuration Register 00034 #define BME280_PRESSURE_MSB_REG 0xF7 //Pressure MSB Register 00035 #define BME280_PRESSURE_LSB_REG 0xF8 //Pressure LSB Register 00036 #define BME280_PRESSURE_XLSB_REG 0xF9 //Pressure XLSB Register 00037 #define BME280_TEMPERATURE_MSB_REG 0xFA //Temperature MSB Reg 00038 #define BME280_TEMPERATURE_LSB_REG 0xFB //Temperature LSB Reg 00039 #define BME280_TEMPERATURE_XLSB_REG 0xFC //Temperature XLSB Reg 00040 #define BME280_HUMIDITY_MSB_REG 0xFD //Humidity MSB Reg 00041 #define BME280_HUMIDITY_LSB_REG 0xFE //Humidity LSB Reg 00042 00043 // Status register bits 00044 #define BME280_STATUS_BUSY 0x08 00045 #define BME280_STATUS_UNKNOWN 0x04 00046 #define BME280_STATUS_IMUPDATE 0x01 00047 00048 #define BME280_RESET_VALUE 0xB6 00049 00050 // Config register equates 00051 #define BME280_OVERSAMPLE_SKIP 0 00052 #define BME280_OVERSAMPLE_x1 1 00053 #define BME280_OVERSAMPLE_x2 2 00054 #define BME280_OVERSAMPLE_x4 3 00055 #define BME280_OVERSAMPLE_x8 4 00056 #define BME280_OVERSAMPLE_x16 5 00057 00058 #define BME280_TEMP_OVERSAMPLE BME280_OVERSAMPLE_x1 //was x2 00059 #define BME280_PRESS_OVERSAMPLE BME280_OVERSAMPLE_x1 //was x4 00060 #define BME280_HUM_OVERSAMPLE BME280_OVERSAMPLE_x1 //was x2 00061 00062 #define BME280_MODE_SLEEP 0 00063 #define BME280_MODE_FORCED 1 00064 #define BME280_MODE_NORMAL 3 00065 00066 #define BME280_STANDBY_0m5 0 00067 #define BME280_STANDBY_62m5 1 00068 #define BME280_STANDBY_125m 2 00069 #define BME280_STANDBY_250m 3 00070 #define BME280_STANDBY_500m 4 00071 #define BME280_STANDBY_1000m 5 00072 #define BME280_STANDBY_10m 6 00073 #define BME280_STANDBY_20m 7 00074 00075 #define BME280_FILTER_OFF 0 00076 #define BME280_FILTER_2 1 00077 #define BME280_FILTER_4 2 00078 #define BME280_FILTER_8 3 00079 #define BME280_FILTER_16 4 00080 00081 //osrs_t(7..5), osrs_p(4..2), mode(1..0) 00082 #define BME280_CTRL_MEAS_REG_DATA ((BME280_TEMP_OVERSAMPLE << 5) | (BME280_PRESS_OVERSAMPLE << 2) | BME280_MODE_NORMAL) 00083 //0(7..3), osrs_h(2..0) 00084 #define BME280_CTRL_HUMIDITY_REG_DATA ((BME280_HUM_OVERSAMPLE)) 00085 //sb(7..5), filter(4..2), 0(1), spl3w_en(0) 00086 #define BME280_CONFIG_REG_DATA ((BME280_STANDBY_1000m << 5) | (BME280_FILTER_OFF << 2)) //was FILTER_4 00087 00088 //Until it is understood why data cannot be raed out of BME280 right after BUSY goes false, the 00089 //defines below introduce a variable delay in main(), based on sb bits used. 00090 // example: wait_ms(BME280_MAIN_WAIT); must be put between pth.getBmeRawData(bmed_struct); accesses 00091 #if ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_0m5) 00092 #define BME280_MAIN_WAIT 100 00093 #elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_62m5) 00094 #define BME280_MAIN_WAIT 60 00095 #elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_125m) 00096 #define BME280_MAIN_WAIT 120 00097 #elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_250m) 00098 #define BME280_MAIN_WAIT 240 00099 #elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_500m) 00100 #define BME280_MAIN_WAIT 100 00101 #elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_1000m) 00102 #define BME280_MAIN_WAIT 500 00103 #elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_10m) 00104 #define BME280_MAIN_WAIT 50 00105 #elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_20m) 00106 #define BME280_MAIN_WAIT 59 00107 #endif 00108 00109 00110 /** 00111 * Create bme280 controller class 00112 * 00113 * @param bme280 class 00114 * 00115 */ 00116 class bme280 { 00117 00118 public: 00119 00120 /** 00121 * Public data structure for CME280 correction values. 00122 * 00123 **/ 00124 typedef struct { 00125 uint16_t dig_T1 ; /*!< calibration parameter -> Temp T1 */ 00126 int16_t dig_T2 ; /*!< calibration parameter -> Temp T2 */ 00127 int16_t dig_T3 ; /*!< calibration parameter -> Temp T3 */ 00128 00129 uint16_t dig_P1 ; /*!< calibration parameter -> Press P1 */ 00130 int16_t dig_P2 ; /*!< calibration parameter -> Press P2 */ 00131 int16_t dig_P3 ; /*!< calibration parameter -> Press P3 */ 00132 int16_t dig_P4 ; /*!< calibration parameter -> Press P4 */ 00133 int16_t dig_P5 ; /*!< calibration parameter -> Press P5 */ 00134 int16_t dig_P6 ; /*!< calibration parameter -> Press P6 */ 00135 int16_t dig_P7 ; /*!< calibration parameter -> Press P7 */ 00136 int16_t dig_P8 ; /*!< calibration parameter -> Press P8 */ 00137 int16_t dig_P9 ; /*!< calibration parameter -> Press P9 */ 00138 00139 uint8_t dig_H1 ; /*!< calibration parameter -> Hum H1 */ 00140 int16_t dig_H2 ; /*!< calibration parameter -> Hum H2 */ 00141 uint8_t dig_H3 ; /*!< calibration parameter -> Hum H3 */ 00142 int16_t dig_H4 ; /*!< calibration parameter -> Hum H4 */ 00143 int16_t dig_H5 ; /*!< calibration parameter -> Hum H5 */ 00144 int8_t dig_H6 ; /*!< calibration parameter -> Hum H6 */ 00145 00146 uint32_t t_fine ; /*!< scratch T_FINE */ 00147 00148 uint8_t ctrl_hum_reg ; /*!< config -> hum */ 00149 uint8_t ctrl_meas_reg ; /*!< config -> temp press mode */ 00150 uint8_t config_reg ; /*!< config -> delay filter spi3w */ 00151 } bme_cal; 00152 00153 /** 00154 * Public data structure to obtain CME280 data. 00155 * 00156 **/ 00157 typedef struct { 00158 int raw_temp ; /*!< raw temperature reading, 20 bits */ 00159 int raw_baro ; /*!< raw pressure reading, 20 bits */ 00160 int raw_hum ; /*!< raw humidity reading, 16 bits */ 00161 int corr_temp ; /*!< corrected temperature as integer*/ 00162 int64_t corr_baro ; /*!< corrected pressure as integer */ 00163 uint32_t corr_hum ; /*!< corrected humidity as integer */ 00164 double bme_temp ; /*!< corrected temperature as a float */ 00165 double bme_baro ; /*!< corrected pressure as a float */ 00166 double bme_hum ; /*!< corrected humidity as a float */ 00167 } bme_data; 00168 00169 /** 00170 * Public enum for selecting polarity of I2C address pin. 00171 * 00172 * - CSB pin = 0, user set I2C address to 0xEC 00173 * - CSB pin = 1, user set I2C address to 0xEE 00174 * 00175 **/ 00176 enum CSBpolarity { 00177 CSBpin_0, //CSB pin is grounded, I2C address is 0xEC and 0xED 00178 CSBpin_1, //CSB pin is tied to Vdd, I2C address is 0xEE and 0xEF 00179 }; 00180 00181 /** 00182 * Create a BME280 object using the specified I2C object 00183 * - User defined use of the CSB pin 00184 * - CSB pin = 0, user set I2C address to 0xEC 00185 * - CSB pin = 1, user set I2C address to 0xEE 00186 * @param sda - mbed I2C interface pin 00187 * @param scl - mbed I2C interface pin 00188 * @param bme280::CSBpin_0 - CSB pin tied to ground 00189 * @param bme280::CSBpin_1 - CSB pin tied to VDD 00190 */ 00191 bme280(PinName sda, PinName scl, CSBpolarity CSBpin); 00192 00193 /** 00194 * Destructor 00195 * 00196 * @param --none-- 00197 */ 00198 ~bme280(); 00199 00200 /** 00201 * Get BME280 ID Register 00202 * 00203 * @param --none-- 00204 * 00205 * @return ID Register value 00206 */ 00207 uint8_t getBmeID(); 00208 00209 /** 00210 * Soft Reset the BME280 00211 * 00212 * @param --none-- 00213 * 00214 * @return ACK/NACK status 00215 */ 00216 uint8_t resetBme(); 00217 00218 /** 00219 * Get BME280 Status Register 00220 * 00221 * @param --none-- 00222 * 00223 * @return Status Register value 00224 */ 00225 uint8_t getBmeStatus(); 00226 00227 /** 00228 * Get BME280 Raw Data 00229 * 00230 * @param pointer to struct bme_data 00231 * 00232 * @return Status Register value. Pass-thru from getBmeStatus() 00233 * @return raw data put into struct bme_data 00234 */ 00235 uint8_t getBmeRawData(bme_data& bmed); 00236 00237 /** 00238 * Convert BME280 Raw Data using integer based routines 00239 * 00240 * @param pointer to struct bme_data 00241 * @param pointer to struct bme_cal 00242 * 00243 * @return converted data put into struct bme_data 00244 */ 00245 void convertBmeRawData(bme_data& bmed, bme_cal& bmec); 00246 00247 /** 00248 * Convert BME280 Raw Data using all floating routines 00249 * 00250 * @param pointer to struct bme_data 00251 * @param pointer to struct bme_cal 00252 * 00253 * @return converted data put into struct bme_data 00254 */ 00255 void convertBmeRawDataFloat(bme_data& bmed, bme_cal& bmec); 00256 00257 /** 00258 * Initialize the BME280. 00259 * - Sets up the command registers 00260 * - Loads up the calibration data 00261 * 00262 * @param pointer to struct bme_data 00263 * 00264 * @return 0 00265 */ 00266 uint8_t initBme(bme_cal& bmec); 00267 00268 /** 00269 * Corrected altitude (feet) from barometer at seal level (mB) 00270 * 00271 * @param pointer to struct bme_data 00272 * @param pressure at sea level (in mB) 00273 * 00274 * @return corrected altimeter (in feet) 00275 */ 00276 float getAltitudeFT(bme_data& bmed, float sea_pressure); 00277 00278 /** 00279 * Altitude corrected barometer (feet) 00280 * 00281 * @param pointer to struct bme_data 00282 * @param known_alt in feet 00283 * 00284 * @return corrected barometer 00285 */ 00286 float getSeaLevelBaroFT(bme_data& bmed, float known_alt); 00287 00288 /** 00289 * Altitude corrected barometer (meters) 00290 * 00291 * @param pointer to struct bme_data 00292 * @param known_alt in meters 00293 * 00294 * @return corrected barometer 00295 */ 00296 float getSeaLevelBaroM(bme_data& bmed, float known_alt); 00297 00298 /** 00299 * Return the dew point based on T & H. Slower but more accurate. 00300 * 00301 * @param pointer to struct bme_data 00302 * 00303 * @return dew point in degrees C 00304 */ 00305 float getDewPt(bme_data& bmed); 00306 00307 /** 00308 * Return the dew point based on T & H. Faster but less accurate. 00309 * 00310 * @param pointer to struct bme_data 00311 * 00312 * @return dew point in degrees C 00313 */ 00314 float getDewPtFast(bme_data& bmed); 00315 00316 private: 00317 #if not defined BMEi2cLOWLEVEL 00318 char bme280Buffer[32]; 00319 #endif 00320 char i2cWAddr; 00321 char i2cRAddr; 00322 int _i2c_start(uint8_t i2c_addr); 00323 void _i2c_stop(); 00324 uint8_t _i2c_write(uint8_t data); 00325 uint8_t _i2c_readACK(); 00326 uint8_t _i2c_readNACK(); 00327 00328 protected: 00329 I2C _i2c; 00330 }; 00331 #endif
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