HTU21D.h

00001 #ifndef HTU21D_H
00002 #define HTU21D_H
00003  
00004 /**
00005  * Includes
00006  */
00007 #include "mbed.h"
00008  
00009 /**
00010  * Defines
00011  */
00012 // Acquired from Datasheet.
00013  
00014 #define HTU21D_I2C_ADDRESS  0x40 
00015 #define TRIGGER_TEMP_MEASURE  0xE3
00016 #define TRIGGER_HUMD_MEASURE  0xE5
00017  
00018  
00019 //Commands.
00020 #define HTU21D_EEPROM_WRITE 0x80
00021 #define HTU21D_EEPROM_READ  0x81
00022  
00023  
00024 /**
00025  * Honeywell HTU21D digital humidity and temperature sensor.
00026  */
00027 class HTU21D {
00028  
00029 public:
00030  
00031     HTU21D();
00032     /**
00033      * Constructor.
00034      *
00035      * @param sda mbed pin to use for SDA line of I2C interface.
00036      * @param scl mbed pin to use for SCL line of I2C interface.
00037      */
00038     HTU21D(PinName sda, PinName scl);
00039  
00040  
00041     /**
00042      * @brief Samples the temperature, input void, outputs an int in celcius. 
00043      * @return  [description]
00044      */
00045     int sample_ctemp(void);
00046     
00047     /**
00048      * @brief Samples the temperature, input void, outputs an int in fahrenheit.
00049      * @return  [description]
00050      */
00051     int sample_ftemp(void);
00052     
00053     /**
00054      * @brief Samples the temperature, input void, outputs an int in kelvin.
00055      * @return  [description]
00056      */
00057     int sample_ktemp(void);
00058     
00059     /**
00060      * @brief Samples the humidity, input void, outputs and int.
00061      * @return  [description]
00062      */
00063     int sample_humid(void);
00064  
00065    
00066  
00067 private:
00068  
00069     I2C* i2c_;
00070  
00071     /**
00072      * Write to EEPROM or RAM on the device.
00073      *
00074      * @param EepromOrRam 0x80 -> Writing to EEPROM
00075      * @param address Address to write to.
00076      * @param data Data to write.
00077      */
00078     void write(int EepromOrRam, int address, int data);
00079  
00080     /**
00081      * Read EEPROM or RAM on the device.
00082      *
00083      * @param EepromOrRam 0x81 -> Reading from EEPROM
00084      * @param address Address to read from.
00085      * @return The contents of the memory address.
00086      */
00087     int read(int EepromOrRam, int address);
00088  
00089 };
00090 
00091 
00092 #endif