const int PIN_Led=4;
const int PIN_3=3;
const int PIN_2=2;

void setup() {
  // put your setup code here, to run once:
  pinMode(PIN_Led, OUTPUT);//inicializamos los pines digitales
  pinMode(PIN_3,OUTPUT);
  pinMode(PIN_2, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(PIN_2, HIGH);
  digitalWrite(PIN_Led, HIGH);//high para decir uno y low para decir 0
  digitalWrite(PIN_3, LOW);

  delay(1000);//1 segundo

  digitalWrite(PIN_Led, LOW);
  digitalWrite(PIN_3,HIGH);
  delay(1000);
}