// declarar variables
int pinLed = 2;
int pinPulsador = 4;
int status = LOW;

void setup() {
 
  pinMode(pinLed, OUTPUT);
  pinMode(pinPulsador, INPUT); 
}

void loop() {
  
  int boton = digitalRead(pinPulsador);
  
  if (boton == HIGH && status == LOW) {
    
    if (digitalRead(pinLed) == LOW) {
      digitalWrite(pinLed, HIGH);
    } else {
      digitalWrite(pinLed, LOW);
    }
   
  } 
  status = boton; 
  delay(10);
}