#define LED PB4

#define F_CPU 8000000UL // 8MH

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

int main() {
  DDRB = (1 << PB0);
  PORTB | (1 << PB0);
  while(1)
  {
    _delay_ms(500);
    PORTB &= ~(1 << PB0);
    _delay_ms(500);
    PORTB = (1 << PB0);
  }
    return 0;
}