unsigned long milli = 4294967295 - 3;
unsigned long tempo = milli;
unsigned long durata = 5;

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println(milli);
  milli += 1;

  unsigned long diff = (milli - tempo);
  Serial.print("diff: ");
  Serial.println(diff);
  if (diff >= durata)
  {
    Serial.println("FIRE");
    tempo = milli;
  }

  delay(1000);
}