#include <avr/io.h>
#include <util/delay.h>
    
    int main (void) {
    
      float sekunden = 10.5;
      int zeit = 1000 * sekunden;
      
       DDRB |= 0b00100000; // 0b00 = 1 (on)/ PIN 13 = 1 
      
      while (1) {
        

        PORTB |= 0b00100000; //13 on
        _delay_ms(zeit); 
        PORTB &= 0b11011111; // 13 off
      }
      return 0; //ende
    }