/*
Modified from Bill Whitaker 20160525
Adapted from Make: AVR Programming by Elliot Williams
*/

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

#define LED      PA7
#define DELAYTIME 200

#define setBit(sfr, bit)     (_SFR_BYTE(sfr) |= (1 << bit))
#define clearBit(sfr, bit)   (_SFR_BYTE(sfr) &= ~(1 << bit))

int main(void) {

  // Initialization
  setBit(DDRA, LED);        /* set LED pin for output */

  // On-off loop
  while (1) {

    setBit(PORTA, LED);     /*turn on LED*/
    _delay_ms(DELAYTIME);   /*wait*/

    clearBit(PORTA, LED);   /*turn off LED*/
    _delay_ms(DELAYTIME);   /*wait*/

  }
  return (0);                                          
}