Code:
#include <avr/io.h>
#include <avr/interrupt.h>


#define F_CPU 1000000UL		// 1MHz




volatile uint16_t timerVal = 0;




void InitTimer() {
	TCCR1B = (1<<WGM12) | (1<<CS12) | (1<<CS10);	// CTC Mode, CLK/1024
	TIMSK1 = (1<<OCIE1A);	// Output Compare A Match Interrupt Enable
	
	OCR1A = 10000;	// Top value
}




int main(void) {
	timerVal = 0;


	InitTimer();


	sei();


	while(1) {
		if(timerVal == 1) {
			DDRA = 0x06;
			timerVal = 0;
		}
	}


	return 0;
}




ISR(TIMER1_COMPA_vect) {
	timerVal++;
}
Mal schnell programmiert, kA obs stimmt.

mfg