int pinLed = 13;
int delayMil = 500;

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

  pinMode(pinLed, OUTPUT);
  Serial.begin(9600);

}

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

  digitalWrite(pinLed, HIGH);
  digitalRead(pinLed);

  delay(delayMil);

  digitalWrite(pinLed, LOW);
  digitalRead(pinLed);

  delay(delayMil);

}