/*
#include <Arduino.h>
#define F_CPU 16000000UL

void isr();
void setup() {
pinMode(5, OUTPUT);
pinMode(2, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(2), isr, CHANGE);
}
void loop() {
}
void isr() {
digitalWrite(5, !digitalRead(5));
}
*/


//////////////////////////////////////////////////////////
#define F_CPU 16000000UL
#include <avr/io.h>
#include <avr/interrupt.h>
#define nop() asm volatile("nop\n")

volatile uint8_t state = 0;

ISR(INT0_vect) { 
	state = !state;
	if (state) {
		PORTD |= (1 << PORTD5);   
		} else {
		PORTD &= ~(1 << PORTD5);  
	}
}

int main(void) {
	DDRD &= ~(1 << DDD2);  
	PORTD |= (1 << PORTD2); 
	DDRD |= (1 << DDD5); 

	EICRA |= (1 << ISC00); 
	EIMSK |= (1 << INT0); 
	sei(); 
	while (1) {
		nop();
	}
}