gistfile1.c

//IRMusicPlayer
//Jennifer Schumaker
//22.Feb.12

// PIND is an Arduino command that gets a byte containing the input
// status of bytes 0 through 7. In our case we want the bit
// corresponding to pin 2. 
// NOTE: If you are seeking input from ports 8 - 15 use PINDB.
// For analong pins 0 - 5 use PINC
//
//

#include "pitches.h"

#define IRInputPin0 1
#define IRInputPin1 2
#define IRInputPin2 4
#define IRInputPin3 8
#define IRInputPin4 16
#define IRInputPin5 32
#define IRInputPin6 64
#define IRInputPin7 128

#define IRpin_PIN  PIND

// PIND brings in a byte each bit of which holds the INPUT status
// of the Arduino's pins 0 through 7. In the following definition
// we select pin 2 to be our input pin for the IR detector. The
// binary value of the number 4 is all zeros except for the bit
// that corresponds to pin 2. To determine if the IR detector is
// seeing infrared we logically combine PIND and IRpin_PIN and test
// this bit.
//      Pin to be tested  Mask in binary  Mask in DEC
//      0                  00000001        1
//      1                  00000010        2
//      2                  00000100        4
//      3                  00001000        8
//      4                  00010000        16
//      5                  00100000        32
//      6                  01000000        64
//      7                  10000000       128
#define IRpin      IRInputPin2
#define NUMBITS 12
#define RES 50
#define LOWUS 600
#define HIGHUS 1200
#define MAXPULSE 5000
#define MAXREST 20000
#define soundPin 4

uint16_t currMessage = 0;

#define HIGHP true
#define LOWP false

void setup(){
  Serial.begin(9600);
}
void loop(){
  if(readIR())
  {
    printFull(currMessage);
  }
}

int wait(boolean type, int timeout)
{
  int num = 0;  // we wait in increments of RES in microseconds.
  while( ( type == HIGHP && (IRpin_PIN & IRpin) )
          ||
         ( type == LOWP && !(IRpin_PIN & IRpin ) ) )
  {
    // pin is still HIGH    
    delayMicroseconds(RES);
    num++;    
    // if the pulse is too long we 'timed out'
    if(num*RES >= timeout) 
    {
      return -1;
    }
  }
  
  return num*RES;  // return the duration of the pulse
}

// Data is collected here.
boolean readIR()
{
  currMessage = 0;
  
  if( wait(HIGHP, MAXREST) == -1)
  {//timeout ( before sees a low pulse)
      Serial.println("Timed out with no pulse");
    return false;
  }
  
    if(wait(LOWP, MAXPULSE) == -1) //start pulse
    {
      Serial.println("Timed out in reading pulse");
      return false; //timeout
    }
      //start decoding message
      
      for(int i = 0;i<NUMBITS;i++)
      {
        if(wait(HIGHP, MAXPULSE) == -1)
         {return false;}
        int data = wait(LOWP, MAXPULSE);
        if(data == -1)
        { return false; } //timeout
        
        // Here the pulse is put in it's
        // appropriate bit position.
        if(data * 2 > LOWUS + HIGHUS)
        {
          //one
          //currMessage = currMessage | (1 << (15-i)); 
          currMessage = currMessage | (1 << i);
          Serial.println("One");
        }
        else
        {
          //zero
          Serial.println("Zero");
        }
      }
      
      return true;
      
}

void printFull(uint16_t n){
  uint8_t command = n & 127;
  uint16_t address = (n >> 7);
  if(command == 4){
    tone(soundPin,NOTE_A4);
  }
  else{
    noTone(soundPin);
  }
}
//////////// END OF PROGRAM /////////////////