#include <avr/io.h>
#include <avr/interrupt.h>
 
// globale Variablen
 
volatile uint8_t flag;
 
int main() {
 

 
// Timer2 konfigurieren
 
    TCCR2  = 6;                     /
    TIMSK |= (1<<TOIE2);            
 

    while(1) {
        if (flag == 1) { 
            flag = 0;
 
          
            PORTD ^= (1 << PD5);    // LED toggeln
        }
    }
}
 
/
ISR( TIMER2_OVF_vect ) {
    flag = 1;
}