BME280.h

00001 /**
00002  ******************************************************************************
00003  * @file    BME280.h
00004  * @author  Toyomasa Watarai
00005  * @version V1.0.0
00006  * @date    11 March 2017
00007  * @brief   This file contains the class of a BME280 Combined humidity and pressure sensor library with I2C interface
00008  ******************************************************************************
00009  * @attention
00010  *
00011  * Permission is hereby granted, free of charge, to any person obtaining a copy
00012  * of this software and associated documentation files (the "Software"), to deal
00013  * in the Software without restriction, including without limitation the rights
00014  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00015  * copies of the Software, and to permit persons to whom the Software is
00016  * furnished to do so, subject to the following conditions:
00017  *
00018  * The above copyright notice and this permission notice shall be included in
00019  * all copies or substantial portions of the Software.
00020  *
00021  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00022  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00023  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00024  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00025  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00026  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00027  * THE SOFTWARE.
00028  */
00029  
00030 /**
00031  *  Library for "BME280 temperature, humidity and pressure sensor module" from Switch Science
00032  *    https://www.switch-science.com/catalog/2236/
00033  *
00034  *  For more information about the BME280:
00035  *    http://ae-bst.resource.bosch.com/media/products/dokumente/bme280/BST-BME280_DS001-10.pdf
00036  */
00037  
00038 #ifndef MBED_BME280_H
00039 #define MBED_BME280_H
00040 
00041 #include "mbed.h"
00042 
00043 #define DEFAULT_SLAVE_ADDRESS (0x77 << 1)
00044 
00045 #ifdef _DEBUG
00046 extern Serial pc;
00047 #define DEBUG_PRINT(...) pc.printf(__VA_ARGS__)
00048 #else
00049 #define DEBUG_PRINT(...)
00050 #endif
00051 
00052 /**  Interface for controlling BME280 Combined humidity and pressure sensor
00053  *
00054  * @code
00055  * #include "mbed.h"
00056  * #include "BME280.h"
00057  * 
00058  * Serial pc(USBTX, USBRX);
00059  * 
00060  * #if defined(TARGET_LPC1768)
00061  * BME280 sensor(p28, p27);
00062  * #else
00063  * BME280 sensor(I2C_SDA, I2C_SCL);
00064  * #endif
00065  * 
00066  * int main() {
00067  *     
00068  *     while(1) {
00069  *         pc.printf("%2.2f degC, %04.2f hPa, %2.2f %%\n", sensor.getTemperature(), sensor.getPressure(), sensor.getHumidity());
00070  *         wait(1);
00071  *     }
00072  * }
00073  * 
00074  * @endcode
00075  */
00076 
00077 /** BME280 class
00078  *
00079  *  BME280: A library to correct environmental data using Boshe BME280 environmental sensor device
00080  *
00081  */ 
00082 class BME280
00083 {
00084 public:
00085 
00086     /** Create a BME280 instance
00087      *  which is connected to specified I2C pins with specified address
00088      *
00089      * @param sda I2C-bus SDA pin
00090      * @param scl I2C-bus SCL pin
00091      * @param slave_adr (option) I2C-bus address (default: 0x76)
00092      */
00093     BME280(PinName sda, PinName sck, char slave_adr = DEFAULT_SLAVE_ADDRESS);
00094 
00095     /** Create a BME280 instance
00096      *  which is connected to specified I2C pins with specified address
00097      *
00098      * @param i2c_obj I2C object (instance)
00099      * @param slave_adr (option) I2C-bus address (default: 0x76)
00100      */
00101     BME280(I2C &i2c_obj, char slave_adr = DEFAULT_SLAVE_ADDRESS);
00102 
00103     /** Destructor of BME280
00104      */
00105     virtual ~BME280();
00106 
00107     /** Initializa BME280 sensor
00108      *
00109      *  Configure sensor setting and read parameters for calibration
00110      *
00111      */
00112     void initialize(void);
00113 
00114     /** Read the current temperature value (degree Celsius) from BME280 sensor
00115      *
00116      */
00117     float getTemperature(void);
00118 
00119     /** Read the current pressure value (hectopascal)from BME280 sensor
00120      *
00121      */
00122     float getPressure(void);
00123 
00124     /** Read the current humidity value (humidity %) from BME280 sensor
00125      *
00126      */
00127     float getHumidity(void);
00128 
00129 private:
00130 
00131     I2C         *i2c_p;
00132     I2C         &i2c;
00133     char        address;
00134     uint16_t    dig_T1;
00135     int16_t     dig_T2, dig_T3;
00136     uint16_t    dig_P1;
00137     int16_t     dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9;
00138     uint16_t    dig_H1, dig_H3;
00139     int16_t     dig_H2, dig_H4, dig_H5, dig_H6;
00140     int32_t     t_fine;
00141 
00142 };
00143 
00144 #endif // MBED_BME280_H