BME280.h

00001  /**
00002  *  Library for "BME280 temperature, humidity and pressure sensor module" from Switch Science
00003  *    https://www.switch-science.com/catalog/2236/
00004  *
00005  *  For more information about the BME280:
00006  *    http://ae-bst.resource.bosch.com/media/products/dokumente/bme280/BST-BME280_DS001-10.pdf
00007  */
00008  
00009 #ifndef MBED_BME280_H
00010 #define MBED_BME280_H
00011 
00012 #include "mbed.h"
00013 
00014 #define DEFAULT_SLAVE_ADDRESS (0x76 << 1)
00015 
00016 #ifdef _DEBUG
00017 //extern Serial pc;
00018 #define DEBUG_PRINT(...) pc.printf(__VA_ARGS__)
00019 #else
00020 #define DEBUG_PRINT(...)
00021 #endif
00022 
00023 /**  Interface for controlling BME280 Combined humidity and pressure sensor
00024  *
00025  * @code
00026  * #include "mbed.h"
00027  * #include "BME280.h"
00028  * 
00029  * Serial pc(USBTX, USBRX);
00030  * 
00031  * #if defined(TARGET_LPC1768)
00032  * BME280 sensor(p28, p27);
00033  * #else
00034  * BME280 sensor(I2C_SDA, I2C_SCL);
00035  * #endif
00036  * 
00037  * int main() {
00038  *     
00039  *     while(1) {
00040  *         pc.printf("%2.2f degC, %04.2f hPa, %2.2f %%\n", sensor.getTemperature(), sensor.getPressure(), sensor.getHumidity());
00041  *         wait(1);
00042  *     }
00043  * }
00044  * 
00045  * @endcode
00046  */
00047 
00048 /** BME280 class
00049  *
00050  *  BME280: A library to correct environmental data using Boshe BME280 environmental sensor device
00051  *
00052  */ 
00053 class BME280
00054 {
00055 public:
00056 
00057     /** Create a BME280 instance
00058      *  which is connected to specified I2C pins with specified address
00059      *
00060      * @param sda I2C-bus SDA pin
00061      * @param scl I2C-bus SCL pin
00062      * @param slave_adr (option) I2C-bus address (default: 0x76)
00063      */
00064     BME280(PinName sda, PinName sck, char slave_adr = DEFAULT_SLAVE_ADDRESS);
00065 
00066     /** Create a BME280 instance
00067      *  which is connected to specified I2C pins with specified address
00068      *
00069      * @param i2c_obj I2C object (instance)
00070      * @param slave_adr (option) I2C-bus address (default: 0x76)
00071      */
00072     BME280(I2C &i2c_obj, char slave_adr = DEFAULT_SLAVE_ADDRESS);
00073 
00074     /** Destructor of BME280
00075      */
00076     virtual ~BME280();
00077 
00078     /** Initializa BME280 sensor
00079      *
00080      *  Configure sensor setting and read parameters for calibration
00081      *
00082      */
00083     void initialize(void);
00084 
00085     /** Read the current temperature value (degree Celsius) from BME280 sensor
00086      *
00087      */
00088     float getTemperature(void);
00089 
00090     /** Read the current pressure value (hectopascal)from BME280 sensor
00091      *
00092      */
00093     float getPressure(void);
00094 
00095     /** Read the current humidity value (humidity %) from BME280 sensor
00096      *
00097      */
00098     float getHumidity(void);
00099 
00100 private:
00101 
00102     I2C         *i2c_p;
00103     I2C         &i2c;
00104     char        address;
00105     uint16_t    dig_T1;
00106     int16_t     dig_T2, dig_T3;
00107     uint16_t    dig_P1;
00108     int16_t     dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9;
00109     uint16_t    dig_H1, dig_H3;
00110     int16_t     dig_H2, dig_H4, dig_H5, dig_H6;
00111     int32_t     t_fine;
00112 
00113 };
00114 
00115 #endif // MBED_BME280_H