const int ledPin = 13;

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED as an output.
  pinMode(13, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
    digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
delay(1000);
    digitalWrite(13, LOW);   // turn the LED on (HIGH is the voltage level)
    delay(1000);
}