int led = 13;
int pauza = 1000; 

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

  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(led, HIGH);
  Serial.println("Svieti");
  delay(pauza);
  
  digitalWrite(led, LOW);
  Serial.println("Nesvieti");
  delay(pauza);
}