#define LED_verde 22
#define LED_rojo 23
unsigned char letra;
int rojo = 0; int verde = 1;
void setup() {
  // put your setup code here, to run once:
  pinMode(LED_verde, OUTPUT);
  pinMode(LED_rojo, OUTPUT);
  Serial.begin(115200);
  Serial.println("Escriba V o R: ");
}
void loop() 
{
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  if (Serial.available()>0) 
  {
    letra = Serial.read(); // leer el byte actual
    if (letra == 'R')
    {
      rojo = 1;
      verde = 0;
    }

    if (letra == 'V')
    {
      verde = 1;
      rojo = 0;
    }
  }
  
  if (rojo == 1)
  {
    digitalWrite(LED_verde, LOW);
    digitalWrite(LED_rojo, HIGH);
    delay(1000);
    digitalWrite(LED_rojo, LOW);
    delay(1000);
  }
  if (verde == 1)
  {
    digitalWrite(LED_rojo, LOW);
    digitalWrite(LED_verde, HIGH);
    delay(1000);
    digitalWrite(LED_verde, LOW);
    delay(1000);
  }
}