/*
  Blink

  Turns an LED on for one second, then off for one second, repeatedly.
*/
#include <avr/io.h>
#include <util/delay.h>

int main(void)
{
  DDRA |= (1<<DDA3);      // set LED pin as output
  PORTA |= (1<<PA3);     // turn on LED by setting pin to high
  while (true)            // repeat continuously
  {
    PINA |= (1<<DDA3);   // toggle state of LED pin
    _delay_ms(1000);
  }
  return (0);
}