const int ledAzul = 8;
const int interruptor = 4;

void setup() {
  pinMode(ledAzul, OUTPUT);
  pinMode(interruptor, INPUT);
}

void loop() {
  // Lê o sinal do interruptor
  int sinal = digitalRead(interruptor);

  // Envia o sinal do interruptor para o led
  digitalWrite(ledAzul, sinal);
}