#define pinoRele 4
#define LedVermelha 6
void setup() 
{

 Serial.begin(9600);
 pinMode(pinoRele, OUTPUT);
 pinMode(LedVermelha, OUTPUT);

 digitalWrite(pinoRele, LOW);// MÓDULO RELÉ INICIAR
 delay(2000);
}

void loop() 
{

 digitalWrite(pinoRele, HIGH); //LOW:Para relé NA. HIG:Para relé NF
 Serial.println("Ligado");
 digitalWrite(LedVermelha, HIGH);
 delay(2000);

 digitalWrite(pinoRele, LOW);
 Serial.println("Desligado");
 digitalWrite(LedVermelha, LOW);
 delay(2000);
}