AtTiny85 externer Interrupt (INT0)

#include <avr/io.h>

#include <avr/interrupt.h>

void interrupt_init()

{

  // rising edge on INT0 creates an interrupt

  MCUCR |= (1 << ISC00)|(1 << ISC01);

  // turns on interrupt for INT0

  GIMSK |= (1 << INT0);

  // allow global interrupts

  sei();

  //or 'SREG |= (1 <<  7);'

}

int main(void)

{  

  //PB1 as OUTPUT

  DDRB |= (1 << PB1);

  //PB2 as INPUT

  DDRB &= ~(1<<PB2);

  //PB2 PULLUP

  PORTB |= (1 << PB2);

  // initialize interrupt

  interrupt_init();

  // loop forever

  while(1)

  {

  }

}

ISR(INT0_vect){

  PORTB ^= ( 1 << PB1 );  

}