#define LED_verde 22
#define LED_rojo 23
#define pulsador 35
unsigned char letra;
int estado= 0;int t1=0;int t2=500;
void IRAM_ATTR cambio()
{
  t1=millis();
  if ((t1-t2)>500)
  {
    if (estado == 1)
    {
      estado = 0;
      t2=t1;
    }
    else
    {
      estado = 1;
      t2=t1;
    }
  }
  
}
void setup()
{
  // put your setup code here, to run once:
  pinMode(LED_rojo, OUTPUT);
  pinMode(pulsador, INPUT_PULLUP);
  pinMode(LED_verde,OUTPUT);
  Serial.begin(9600);
  delay(1000);
  Serial.println("Dos leds con pulsador");
  attachInterrupt(digitalPinToInterrupt(pulsador), cambio, RISING);
}

void loop() 
{
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  
  
  if (estado == 1)
  {
    digitalWrite(LED_verde, LOW);
    digitalWrite(LED_rojo, HIGH);
    delay(1000);
    digitalWrite(LED_rojo, LOW);
    delay(1000);
  }
  if (estado == 0)
  {
    digitalWrite(LED_rojo, LOW);
    digitalWrite(LED_verde, HIGH);
    delay(1000);
    digitalWrite(LED_verde, LOW);
    delay(1000);
  }
}