printTimerInterrupts.ino

void setup() {
  // put your setup code here, to run once:

  //TCCR1A = B00000000; //Normal Mode, no automatic pin toggling
  //TCCR1B = _BV(CS12) | _BV(CS10); //Set up x1024 prescaler
  TIMSK1 |= _BV(TOIE1);

  Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
}

ISR(TIMER1_OVF_vect){
  Serial.println(millis());
}