#include<avr/io.h>
#include<util/delay.h>
#include <avr/interrupt.h>
#define DELAY_TIME 150

volatile uint8_t id;
volatile uint8_t state;

ISR(TIMER2_OVF_vect, ISR_NAKED)
{
	if(state == 0){
	  PORTC &= ~(1<<id);
	  state++;
	}else{
	  PORTC |= (1<<id);
	  state = 0;
	  id++;
	  if(id == 8)
		id = 0;
	}
	reti();
}

void set_led(int id){
  PORTC &= ~(1<<id);
  _delay_ms(DELAY_TIME);
  PORTC |= (1<<id);
  _delay_ms(DELAY_TIME);
}

int main(void) {
 DDRC = (0xff);
 PORTC = (0xff);
 
 TCCR2B |= (0b111);
 
 TIMSK2 |= 0b1;
 
 sei();
 
 for(;;);

 return 0;
}