//Declaramos variables, indicamos que usaremos un Led rojo en el pin 12
int LedR=12;

void setup()
{
  pinMode(LedR, OUTPUT);
  // put your setup code here, to run once:

}

void loop() 
{
  digitalWrite(LedR, HIGH);
  delay(2000);
  digitalWrite(LedR, LOW);
  delay(2000);
  // put your main code here, to run repeatedly:

}