// Constantes
const int ledVermelho = 13;
const int ledAmarelo = 12;
const int ledVerde = 11;

void setup() {
  pinMode(ledVermelho, OUTPUT);
  pinMode(ledAmarelo, OUTPUT);
  pinMode(ledVerde, OUTPUT);
  // Inicializa o semáforo
  digitalWrite(ledVermelho, LOW);
  digitalWrite(ledAmarelo, LOW);
  digitalWrite(ledVerde, LOW);
}

void loop() {
  digitalWrite(ledVermelho, HIGH);
  delay(10000); // 10 s
  digitalWrite(ledVermelho, LOW);
  digitalWrite(ledVerde, HIGH);
  delay(8000); // 8 s
  digitalWrite(ledVerde, LOW);
  digitalWrite(ledAmarelo, HIGH);
  delay(2000); // 2 s
  digitalWrite(ledAmarelo, LOW);
}