// Sinal - Semáforo
int ledDelay = 10000; // delay entre as mudancas
int redPin = 23;
int yellowPin = 22;
int greenPin = 21;
void setup() {
pinMode(redPin, OUTPUT);
pinMode(yellowPin, OUTPUT);
pinMode(greenPin, OUTPUT);
}
void loop() {
  // liga o vermelho
  digitalWrite(redPin, HIGH);
  delay(ledDelay); // aguarda 5 segundos
  digitalWrite(greenPin, HIGH); // liga o verde
  digitalWrite(redPin, LOW); // desliga o vermelho
  digitalWrite(yellowPin, LOW); // desliga o amarelo
  delay(ledDelay); // aguarda ledDelay milisegundos
  digitalWrite(yellowPin, HIGH); // liga o amarelo
  digitalWrite(greenPin, LOW); // desliga o verde
  delay(2000); // aguarda 2 segundos
  digitalWrite(yellowPin, LOW); // desliga o amarelo
  // repete o loop
}