Semaforo Arduino

// the setup function runs once when you press reset or power the board

void setup() {

  // initialize digital pin LED_BUILTIN as an output.

  pinMode(13, OUTPUT);

  pinMode(12, OUTPUT);

  pinMode(11, OUTPUT);

}

// the loop function runs over and over again forever

void loop() {

  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)

  delay(3000);                       // wait for a second

  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW

  delay(3000);                       // wait for a second

  digitalWrite(12, HIGH);   // turn the LED on (HIGH is the voltage level)

  delay(1000);                       // wait for a second

  digitalWrite(12, LOW);    // turn the LED off by making the voltage LOW

  delay(1000); 

  digitalWrite(11, HIGH);   // turn the LED on (HIGH is the voltage level)

  delay(3000);                       // wait for a second

  digitalWrite(11, LOW);    // turn the LED off by making the voltage LOW

  delay(3000);    

}

Explicación: Gracias al programa de arduino hemos podido imitar las luces de un semáforo (rojo, ámbar y verde). Para ello se necesitaran tres bombillas de colores (preferiblemente rojo verde y amarillo), siete cables para conectarlo todo a la placa de arduino y por último una placa protoboard.