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Hier is die StartSwitch():
Code:
void StartSwitch(void)
{
	SWITCH_OFF;
	DDRD &= ~SWITCHES;	// Switches as Input => ext. Int 1
	MCUCR &= ~((1 << ISC11) | (1 << ISC10));// Low level generates interrupt
	GICR |= (1 << INT1);					// Enable external Interrupt 1 
}