IRdecoder.h

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#pragma once 
 
#include <Arduino.h>
 
class IRDecoder
{
private:
  uint8_t pin = -1;
 
  enum IR_STATE
  {
    IR_READY,    //idle, returns to this state after you request a code
    IR_PREAMBLE, //received the start burst, waiting for first bit
    IR_REPEAT,   //received repeat code (part of NEC protocol); last code will be returned
    IR_ACTIVE,   //have some bits, but not yet complete
    IR_COMPLETE, //a valid code has been received
    IR_ERROR     //an error occurred; won't return a valid code
  }; 
 
  IR_STATE state = IR_READY; //a simple state machine for managing reception
 
  volatile uint32_t lastReceiveTime = 0; //not really used -- could be used to sunset codes
 
  volatile uint32_t currCode = 0; //the most recently received valid code
  volatile uint8_t index = 0;     //for tracking which bit we're on
 
  volatile uint32_t fallingEdge = 0;
  volatile uint32_t risingEdge = 0;
 
  volatile uint32_t lastRisingEdge = 0; //used for tracking spacing between rising edges, i.e., bit value
public:
  //volatile uint16_t bits[32];  //I used this for debugging; obsolete
 
public:
  IRDecoder(uint8_t p) : pin(p) {}
  void init(void);           //call this in the setup()
  void handleIRsensor(void); //ISR
 
  uint32_t getCode(void) //returns the most recent valid code; returns zero if there was an error
  {
    if (state == IR_COMPLETE || state == IR_REPEAT)
    {
      state = IR_READY;
      return currCode;
    }
    else
      return 0;
  }
 
  int16_t getKeyCode(bool acceptRepeat = false) //returns the most recent key code; returns -1 on error (not sure if 0 can be a code or not!!!)
  {
    if (state == IR_COMPLETE || (acceptRepeat == true && state == IR_REPEAT))
    {
      state = IR_READY;
      return (currCode >> 16) & 0x0ff;
    }
    else
      return -1;
  }
};
 
extern IRDecoder decoder;