#include <TimerOne.h>


void setup() 
{
pinMode(3, OUTPUT);

Timer1.initialize(1000); 		//zapne timer1 interrupty (5 ms)
Timer1.attachInterrupt(Timer1_ISR);	
}
void loop() 
{
}


void Timer1_ISR()
{	
digitalWrite(3, HIGH);						//PB3
digitalWrite(3, LOW);
}