Libery for DHT-22 temp sensor

Dependents:   Brew_Keg

Fork of DHT by Wim De Roeve

DHT.h

Committer:
gert_lauritsen
Date:
2016-02-05
Revision:
1:6ddabfde1db6
Parent:
0:9b5b3200688f

File content as of revision 1:6ddabfde1db6:

/* 
 *  DHT Library for  Digital-output Humidity and Temperature sensors 
 *  
 *  Works with DHT11, DHT21, DHT22
 *             SEN11301P,  Grove - Temperature&Humidity Sensor     (Seeed Studio)
 *             SEN51035P,  Grove - Temperature&Humidity Sensor Pro (Seeed Studio)
 *             AM2302   ,  temperature-humidity sensor    
 *             RHT01,RHT02, RHT03    ,  Humidity and Temperature Sensor         (Sparkfun)
 *
 *  Copyright (C) Wim De Roeve
 *                based on DHT22 sensor library by HO WING KIT
 *                Arduino DHT11 library
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documnetation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to  whom the Software is
 * furished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS OR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef MBED_DHT_H
#define MBED_DHT_H

#include "mbed.h"

enum eType{
        DHT11     = 11,
        SEN11301P = 11,
        RHT01     = 11,
        DHT22     = 22,
        AM2302    = 22,
        SEN51035P = 22,
        RHT02     = 22,
        RHT03     = 22
    } ;

enum eError {
    ERROR_NONE = 0,
    BUS_BUSY =1,
    ERROR_NOT_PRESENT =2 ,
    ERROR_ACK_TOO_LONG =3 ,
    ERROR_SYNC_TIMEOUT = 4,
    ERROR_DATA_TIMEOUT =5 ,
    ERROR_CHECKSUM = 6,
    ERROR_NO_PATIENCE =7
} ;

typedef enum {
    CELCIUS =0 ,
    FARENHEIT =1,
    KELVIN=2
} eScale;


class DHT {

public:

    DHT(PinName pin,int DHTtype);
    ~DHT();
    int readData(void);
    float ReadHumidity(void);
    float ReadTemperature(eScale Scale);
    float CalcdewPoint(float celsius, float humidity);
    float CalcdewPointFast(float celsius, float humidity);

private:
    time_t  _lastReadTime;
    float _lastTemperature;
    float _lastHumidity;
    PinName _pin;
    bool _firsttime;
    int _DHTtype;
    int DHT_data[6];
    float CalcTemperature();
    float CalcHumidity();
    float ConvertCelciustoFarenheit(float);
    float ConvertCelciustoKelvin(float);

};

#endif