DHTStable.h

#pragma once
//
//    FILE: DHTStable.h
//  AUTHOR: Rob Tillaart
// VERSION: 1.1.2
// PURPOSE: DHT Temperature & Humidity Sensor library for Arduino
//     URL: https://github.com/RobTillaart/DHTstable


#include "Arduino.h"

#define DHTSTABLE_LIB_VERSION           (F("1.1.2 - DHTStable"))


const int DHTLIB_OK              = 0;
const int DHTLIB_ERROR_CHECKSUM  = -1;
const int DHTLIB_ERROR_TIMEOUT   = -2;
const int DHTLIB_INVALID_VALUE   = -999;

const int DHTLIB_DHT11_WAKEUP    = 18;
const int DHTLIB_DHT_WAKEUP      = 1;


//  max timeout is 100usec.
//  For a 16Mhz processor that is max 1600 clock cycles
//  loops using TIMEOUT use at least 4 clock cycles
//  so 100 us takes max 400 loops
//  so by dividing F_CPU by 40000 we "fail" as fast as possible
const int DHTLIB_TIMEOUT = (F_CPU/40000);


class DHTStable
{
public:
  DHTStable();

  void reset();

  //  return values:
  //  DHTLIB_OK
  //  DHTLIB_ERROR_CHECKSUM
  //  DHTLIB_ERROR_TIMEOUT
  int read11(uint8_t pin);      //  DHT11 & DHT12
  int read(uint8_t pin);        //  DHT22

  inline int read12(uint8_t pin)   { return read11(pin); };  //  ok
  inline int read21(uint8_t pin)   { return read(pin); };    //  ok
  inline int read22(uint8_t pin)   { return read(pin); };    //  ok
  inline int read33(uint8_t pin)   { return read(pin); };    //  ok
  inline int read44(uint8_t pin)   { return read(pin); };    //  ok
  inline int read2301(uint8_t pin) { return read(pin); };    //  ok
  inline int read2302(uint8_t pin) { return read(pin); };    //  ok
  inline int read2320(uint8_t pin) { return read(pin); };    //  ok
  inline int read2322(uint8_t pin) { return read(pin); };    //  ok

  //  read values from cache, call read() to refresh!
  float getHumidity()    { return _humidity; };
  float getTemperature() { return _temperature; };

  bool  getDisableIRQ()            { return _disableIRQ; };
  void  setDisableIRQ(bool b )     { _disableIRQ = b; };

private:
  uint8_t _bits[5];  //  buffer to receive data
  int     _readSensor(uint8_t pin, uint8_t wakeupDelay);
  bool    _disableIRQ = false;
  float   _humidity;
  float   _temperature;
};


//  -- END OF FILE --