avr_hackery2.c

#include <avr/io.h>

int main(void){

  unsigned int PIN = 5;

  TCCR1B |= ((1 << CS10) | (1 << CS12));
  
  DDRB |= (1 << PIN); // enable LED pin in DDRB register

  for (;;){
    if (TCNT1 >= 7812){
      PORTB ^= (1 << PIN); 
      TCNT1 = 0;
    }
  }


}