const int LED_PIN = 13;
const int INTERRUPT_PIN = 2;
int cas = 0;
//unsigned long previousMillis = 0UL;
//unsigned long interval = 1000UL;

void setup() {
  // put your setup code here, to run once:
  pinMode(LED_PIN, OUTPUT);
  pinMode(INTERRUPT_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), resetcasovac, FALLING);
  Serial.begin(9600);
  return run();
}

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

}

void run(){

    for(cas; cas < 30;cas++){
    delay(1000);
      //unsigned long currentMillis = millis();

  //if(currentMillis - previousMillis > interval)
  //{
    //cas++;
 	//previousMillis = currentMillis;
    Serial.println(cas);
  //}
    if(cas>20){
      digitalWrite(LED_PIN, HIGH);
    }

  }
  Serial.println("Tlacitko nezmacknuto.");

}

void resetcasovac(){
  cas = 0;
  digitalWrite(LED_PIN, LOW);
  Serial.println("Tlacitko zmacknuto.");


}