#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

//32 bit code
int code = 0b11111111100000000111111011100001;

//length of each bit
#define BIT_LENGTH 10

//Generates the carrier requency for the supplied timeframe
void carrier(int BlastTime) {
  for(int i=0; i<(BlastTime / 2); i++)
  {
    PORTB |= (1 << 0x04);
    _delay_ms(BIT_LENGTH);
    PORTB &= ~(1 << 0x04);
    _delay_ms(BIT_LENGTH);
  }
  return;
}

// send '1' bit
int sendShort(void){
  carrier(BIT_LENGTH);
  _delay_ms(BIT_LENGTH);
  return 0;
}

// send '0/ bit
int sendLong(void){
  _delay_ms(BIT_LENGTH);
  carrier(BIT_LENGTH);
  _delay_ms(BIT_LENGTH);
  return 0;
}

//Send the entire code including init, start, and end bits
void sendBlast(void) { 
  carrier(20);
  _delay_ms(20);

  //start bit
  sendShort();
  _delay_ms(BIT_LENGTH);
  
    for(int i=0; i<32; i++){
        if (code &0x80000000){
            sendShort();
        }
        else{
            sendLong();
        code<<=1;
        }
    }

  //stop bit
  sendShort();
}

int main(void) {
  //PB1 Button (pin 6); PB4 LED (pin 3)

  DDRB |= (1 << 0x04); // Set PB4 Output
  PORTB |= (1 << 0x01); //Set PB1 high

  while(true)
  {
    if ((PINB & (1 << 0x01)) == 0){ //if the button is pushed start sending code
      sendBlast();
    }
    else {
      PORTB &= ~(1 << 0x04); //if the button is not pushed make sure PB4 is off
    }
  }
}