Sht31.h

00001 /***************************************************
00002   This is a library for the SHT31 Digital Humidity & Temp Sht31
00003 
00004   Designed specifically to work with the SHT31 Digital Sht31 from Adafruit
00005   ----> https://www.adafruit.com/products/2857
00006 
00007   These displays use I2C to communicate, 2 pins are required to
00008   interface
00009   Adafruit invests time and resources providing this open source code,
00010   please support Adafruit and open-source hardware by purchasing
00011   products from Adafruit!
00012 
00013   Written by Limor Fried/Ladyada for Adafruit Industries.
00014   BSD license, all text above must be included in any redistribution
00015  ****************************************************/
00016 
00017 #ifndef Sht31_H
00018 #define Sht31_H
00019 
00020 #include "mbed.h"
00021 
00022 #define SHT31_DEFAULT_ADDR          0x44
00023 #define SHT31_MEAS_HIGHREP_STRETCH  0x2C06
00024 #define SHT31_MEAS_MEDREP_STRETCH   0x2C0D
00025 #define SHT31_MEAS_LOWREP_STRETCH   0x2C10
00026 #define SHT31_MEAS_HIGHREP          0x2400
00027 #define SHT31_MEAS_MEDREP           0x240B
00028 #define SHT31_MEAS_LOWREP           0x2416
00029 #define SHT31_READSTATUS            0xF32D
00030 #define SHT31_CLEARSTATUS           0x3041
00031 #define SHT31_SOFTRESET             0x30A2
00032 #define SHT31_HEATEREN              0x306D
00033 #define SHT31_HEATERDIS             0x3066
00034 
00035 class Sht31 {
00036 public:
00037     Sht31(PinName sda, PinName scl);
00038     float readTemperature(void);
00039     float readHumidity(void);
00040 
00041 private:
00042     void reset(void);
00043     uint16_t readStatus(void);
00044     void writeCommand(uint16_t cmd);
00045     bool readTempHum(void);
00046     uint8_t crc8(const uint8_t *data, int len);
00047 
00048     I2C _i2c;
00049     int _i2caddr;
00050     float humidity, temp;
00051 };
00052 
00053 #endif