//Using IR Transmitter/Receiver to sound the buzzer for Dragon12 Plus Trainer Board 
//PT5 of PORTT is connected to buzzer/speaker on Dragon12+ board
//This program sounds the buzzer whenever the IR detects an object
//Put your hands in front of them and buzzer will sound. Remove your hnad and buzzer will stop 

//On Dragon12 board the PT4 is used to turn on the Astable multivibrator (Square wave Freq generator) made of 4093 chip
//It is an active low so PT4=0 turns it on and it provides 38KHz frequency to IR Transmitter (IRTX)
//The IR Receiver (IRRX) is connected to PT3. So we can sample the IR receiver (PT3) as many times per second as we wnat (10 times per second)
//Written and tested by M. Mazidi with some input from Travis Chandler.

//MAKE SURE YOU MOVE THE JUMPERS ON J27 (IT IS BOTTOM LEFT OF CPU) BEFORE RUNNING THIS PROGRAM
//PUT JUMPER BETWEEN 6 AND 5 (SIDEWAY VERTICAL). ALSO PUT JUMPER BETWEEN 4 AND 5 (SIDEWAY VERTICAL)
//IF JUMPERS ARE SET PROPERLY BOTH TX AND RX LEDs ARE TURNED ON        


#include <hidef.h>      /* common defines and macros */
#include "derivative.h"      /* derivative-specific definitions */


void MSDelay(unsigned int);
void main(void) 
{
  /* put your own code here */
  
     
  
  DDRT = DDRT | 0b00110000;   //PT5=out for buzzer, PT4=out for IR Transmitter (IRTX),PT3=in for IR Receiver (IRRX)
  PTT = PTT & 0b11101111;     //turn on Astabale Multivibrator(4093 chip) 38 KHz Freq genrator (it is active Low)

   while(1)
   {
      if(PTT & 0x08)     //sample the receiver
      {
         PTT = PTT ^ 0b00100000; 	//if high toggle the buzzer (you can use PWM to sound the buzzer for better sound)
         MSDelay(10);             //change this for different buzzer sounds
      } 
      
       MSDelay(10);             //sample it 10 times per second
   }
  

}

void MSDelay(unsigned int itime)  //msec delay
  {
    unsigned int i; unsigned int j;
    for(i=0;i<itime;i++)
      for(j=0;j<4000;j++);
  }