Kevin Braun
Multi environmental sensor
My version of the bme280 pressure, humidity and temperature sensor
Diff: bme280.h
- Revision:
- 3:96075bee19f0
- Parent:
- 0:40b4ebf843c6
- Child:
- 2:bb91307d5c4d
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/bme280.h Fri Apr 22 14:25:55 2016 +0000
@@ -0,0 +1,331 @@
+#ifndef BME280_H
+#define BME280_H
+
+#include "mbed.h"
+
+#if(defined(TARGET_KL25Z) || defined(TARGET_K64F))
+
+// #define BME280i2cLOWLEVEL 1 //if the use of low-level I2C routines is needed
+// #warning "BME280 using low level I2C routines"
+
+#endif
+
+
+#define SEA_PRESS 1013.25 //default sea level pressure level in mb
+//#define KNOWNALT 327.0 //default known altitude in feet
+#define METERS_FEET 3.2808399
+#define FEET_METERS 0.3048006
+#define MB_INHG_DOUBLE 0.02952998751
+#define INHG_MB_DOUBLE 33.8638815767
+#define DEGC_DEGF_FLOAT 9.0 / 5.0 + 32.0
+#define DEGC_DEGF_INT 9 / 5 + 32
+
+#define BME280_WADDR 0xEC //i2c address write mode (CSBpin = 0);
+#define BME280_RADDR 0xED //i2c address read mode
+
+#define BME280_CHIP_ID_REG 0xD0 //Chip ID Register
+#define BME280_CAL_DATA_START_1 0x88 //Calibration data parameters
+#define BME280_CAL_DATA_START_2 0xE1 //More calibration data parameters
+#define BME280_RST_REG 0xE0 //Softreset Register
+#define BME280_STAT_REG 0xF3 //Status Register
+#define BME280_CTRL_MEAS_REG 0xF4 //Ctrl Measure Register
+#define BME280_CTRL_HUMIDITY_REG 0xF2 //Ctrl Humidity Register
+#define BME280_CONFIG_REG 0xF5 //Configuration Register
+#define BME280_PRESSURE_MSB_REG 0xF7 //Pressure MSB Register
+#define BME280_PRESSURE_LSB_REG 0xF8 //Pressure LSB Register
+#define BME280_PRESSURE_XLSB_REG 0xF9 //Pressure XLSB Register
+#define BME280_TEMPERATURE_MSB_REG 0xFA //Temperature MSB Reg
+#define BME280_TEMPERATURE_LSB_REG 0xFB //Temperature LSB Reg
+#define BME280_TEMPERATURE_XLSB_REG 0xFC //Temperature XLSB Reg
+#define BME280_HUMIDITY_MSB_REG 0xFD //Humidity MSB Reg
+#define BME280_HUMIDITY_LSB_REG 0xFE //Humidity LSB Reg
+
+// Status register bits
+#define BME280_STATUS_BUSY 0x08
+#define BME280_STATUS_UNKNOWN 0x04
+#define BME280_STATUS_IMUPDATE 0x01
+
+#define BME280_RESET_VALUE 0xB6
+
+// Config register equates
+#define BME280_OVERSAMPLE_SKIP 0
+#define BME280_OVERSAMPLE_x1 1
+#define BME280_OVERSAMPLE_x2 2
+#define BME280_OVERSAMPLE_x4 3
+#define BME280_OVERSAMPLE_x8 4
+#define BME280_OVERSAMPLE_x16 5
+
+#define BME280_TEMP_OVERSAMPLE BME280_OVERSAMPLE_x1 //was x2
+#define BME280_PRESS_OVERSAMPLE BME280_OVERSAMPLE_x1 //was x4
+#define BME280_HUM_OVERSAMPLE BME280_OVERSAMPLE_x1 //was x2
+
+#define BME280_MODE_SLEEP 0
+#define BME280_MODE_FORCED 1
+#define BME280_MODE_NORMAL 3
+
+#define BME280_STANDBY_0m5 0
+#define BME280_STANDBY_62m5 1
+#define BME280_STANDBY_125m 2
+#define BME280_STANDBY_250m 3
+#define BME280_STANDBY_500m 4
+#define BME280_STANDBY_1000m 5
+#define BME280_STANDBY_10m 6
+#define BME280_STANDBY_20m 7
+
+#define BME280_FILTER_OFF 0
+#define BME280_FILTER_2 1
+#define BME280_FILTER_4 2
+#define BME280_FILTER_8 3
+#define BME280_FILTER_16 4
+
+//osrs_t(7..5), osrs_p(4..2), mode(1..0)
+#define BME280_CTRL_MEAS_REG_DATA ((BME280_TEMP_OVERSAMPLE << 5) | (BME280_PRESS_OVERSAMPLE << 2) | BME280_MODE_NORMAL)
+//0(7..3), osrs_h(2..0)
+#define BME280_CTRL_HUMIDITY_REG_DATA ((BME280_HUM_OVERSAMPLE))
+//sb(7..5), filter(4..2), 0(1), spl3w_en(0)
+#define BME280_CONFIG_REG_DATA ((BME280_STANDBY_1000m << 5) | (BME280_FILTER_OFF << 2)) //was FILTER_4
+
+//Until it is understood why data cannot be raed out of BME280 right after BUSY goes false, the
+//defines below introduce a variable delay in main(), based on sb bits used.
+// example: wait_ms(BME280_MAIN_WAIT); must be put between pth.getBmeRawData(bmed_struct); accesses
+#if ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_0m5)
+#define BME280_MAIN_WAIT 100
+#elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_62m5)
+#define BME280_MAIN_WAIT 60
+#elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_125m)
+#define BME280_MAIN_WAIT 120
+#elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_250m)
+#define BME280_MAIN_WAIT 240
+#elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_500m)
+#define BME280_MAIN_WAIT 100
+#elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_1000m)
+#define BME280_MAIN_WAIT 500
+#elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_10m)
+#define BME280_MAIN_WAIT 50
+#elif ((BME280_CONFIG_REG_DATA >> 5) == BME280_STANDBY_20m)
+#define BME280_MAIN_WAIT 59
+#endif
+
+
+ /**
+ * Create bme280 controller class
+ *
+ * @param bme280 class
+ *
+ */
+class bme280 {
+
+public:
+
+ /**
+ * Public data structure for CME280 correction values.
+ *
+ **/
+ typedef struct {
+ uint16_t dig_T1; /*!< calibration parameter -> Temp T1 */
+ int16_t dig_T2; /*!< calibration parameter -> Temp T2 */
+ int16_t dig_T3; /*!< calibration parameter -> Temp T3 */
+
+ uint16_t dig_P1; /*!< calibration parameter -> Press P1 */
+ int16_t dig_P2; /*!< calibration parameter -> Press P2 */
+ int16_t dig_P3; /*!< calibration parameter -> Press P3 */
+ int16_t dig_P4; /*!< calibration parameter -> Press P4 */
+ int16_t dig_P5; /*!< calibration parameter -> Press P5 */
+ int16_t dig_P6; /*!< calibration parameter -> Press P6 */
+ int16_t dig_P7; /*!< calibration parameter -> Press P7 */
+ int16_t dig_P8; /*!< calibration parameter -> Press P8 */
+ int16_t dig_P9; /*!< calibration parameter -> Press P9 */
+
+ uint8_t dig_H1; /*!< calibration parameter -> Hum H1 */
+ int16_t dig_H2; /*!< calibration parameter -> Hum H2 */
+ uint8_t dig_H3; /*!< calibration parameter -> Hum H3 */
+ int16_t dig_H4; /*!< calibration parameter -> Hum H4 */
+ int16_t dig_H5; /*!< calibration parameter -> Hum H5 */
+ int8_t dig_H6; /*!< calibration parameter -> Hum H6 */
+
+ uint32_t t_fine; /*!< scratch T_FINE */
+
+ uint8_t ctrl_hum_reg; /*!< config -> hum */
+ uint8_t ctrl_meas_reg; /*!< config -> temp press mode */
+ uint8_t config_reg; /*!< config -> delay filter spi3w */
+ } bme_cal;
+
+ /**
+ * Public data structure to obtain CME280 data.
+ *
+ **/
+ typedef struct {
+ int raw_temp; /*!< raw temperature reading, 20 bits */
+ int raw_baro; /*!< raw pressure reading, 20 bits */
+ int raw_hum; /*!< raw humidity reading, 16 bits */
+ int corr_temp; /*!< corrected temperature as integer*/
+ int64_t corr_baro; /*!< corrected pressure as integer */
+ uint32_t corr_hum; /*!< corrected humidity as integer */
+ double bme_temp; /*!< corrected temperature as a float */
+ double bme_baro; /*!< corrected pressure as a float */
+ double bme_hum; /*!< corrected humidity as a float */
+ } bme_data;
+
+ /**
+ * Public enum for selecting polarity of I2C address pin.
+ *
+ * - CSB pin = 0, user set I2C address to 0xEC
+ * - CSB pin = 1, user set I2C address to 0xEE
+ *
+ **/
+ enum CSBpolarity {
+ CSBpin_0, //CSB pin is grounded, I2C address is 0xEC and 0xED
+ CSBpin_1, //CSB pin is tied to Vdd, I2C address is 0xEE and 0xEF
+ };
+
+ /**
+ * Create a BME280 object using the specified I2C object
+ * - User defined use of the CSB pin
+ * - CSB pin = 0, user set I2C address to 0xEC
+ * - CSB pin = 1, user set I2C address to 0xEE
+ * @param sda - mbed I2C interface pin
+ * @param scl - mbed I2C interface pin
+ * @param bme280::CSBpin_0 - CSB pin tied to ground
+ * @param bme280::CSBpin_1 - CSB pin tied to VDD
+ */
+ bme280(PinName sda, PinName scl, CSBpolarity CSBpin);
+
+ /**
+ * Destructor
+ *
+ * @param --none--
+ */
+ ~bme280();
+
+ /**
+ * Get BME280 ID Register
+ *
+ * @param --none--
+ *
+ * @return ID Register value
+ */
+ uint8_t getBmeID();
+
+ /**
+ * Soft Reset the BME280
+ *
+ * @param --none--
+ *
+ * @return ACK/NACK status
+ */
+ uint8_t resetBme();
+
+ /**
+ * Get BME280 Status Register
+ *
+ * @param --none--
+ *
+ * @return Status Register value
+ */
+ uint8_t getBmeStatus();
+
+ /**
+ * Get BME280 Raw Data
+ *
+ * @param pointer to struct bme_data
+ *
+ * @return Status Register value. Pass-thru from getBmeStatus()
+ * @return raw data put into struct bme_data
+ */
+ uint8_t getBmeRawData(bme_data& bmed);
+
+ /**
+ * Convert BME280 Raw Data using integer based routines
+ *
+ * @param pointer to struct bme_data
+ * @param pointer to struct bme_cal
+ *
+ * @return converted data put into struct bme_data
+ */
+ void convertBmeRawData(bme_data& bmed, bme_cal& bmec);
+
+ /**
+ * Convert BME280 Raw Data using all floating routines
+ *
+ * @param pointer to struct bme_data
+ * @param pointer to struct bme_cal
+ *
+ * @return converted data put into struct bme_data
+ */
+ void convertBmeRawDataFloat(bme_data& bmed, bme_cal& bmec);
+
+ /**
+ * Initialize the BME280.
+ * - Sets up the command registers
+ * - Loads up the calibration data
+ *
+ * @param pointer to struct bme_data
+ *
+ * @return 0
+ */
+ uint8_t initBme(bme_cal& bmec);
+
+ /**
+ * Corrected altitude (feet) from barometer at seal level (mB)
+ *
+ * @param pointer to struct bme_data
+ * @param pressure at sea level (in mB)
+ *
+ * @return corrected altimeter (in feet)
+ */
+ float getAltitudeFT(bme_data& bmed, float sea_pressure);
+
+ /**
+ * Altitude corrected barometer (feet)
+ *
+ * @param pointer to struct bme_data
+ * @param known_alt in feet
+ *
+ * @return corrected barometer
+ */
+ float getSeaLevelBaroFT(bme_data& bmed, float known_alt);
+
+ /**
+ * Altitude corrected barometer (meters)
+ *
+ * @param pointer to struct bme_data
+ * @param known_alt in meters
+ *
+ * @return corrected barometer
+ */
+ float getSeaLevelBaroM(bme_data& bmed, float known_alt);
+
+ /**
+ * Return the dew point based on T & H. Slower but more accurate.
+ *
+ * @param pointer to struct bme_data
+ *
+ * @return dew point in degrees C
+ */
+ float getDewPt(bme_data& bmed);
+
+ /**
+ * Return the dew point based on T & H. Faster but less accurate.
+ *
+ * @param pointer to struct bme_data
+ *
+ * @return dew point in degrees C
+ */
+ float getDewPtFast(bme_data& bmed);
+
+private:
+#if not defined BMEi2cLOWLEVEL
+ char bme280Buffer[32];
+#endif
+ char i2cWAddr;
+ char i2cRAddr;
+ int _i2c_start(uint8_t i2c_addr);
+ void _i2c_stop();
+ uint8_t _i2c_write(uint8_t data);
+ uint8_t _i2c_readACK();
+ uint8_t _i2c_readNACK();
+
+protected:
+ I2C _i2c;
+};
+#endif
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