const int TRIG =10;
const int ECO =9;
const int LED =3;
int DURACION;
int DISTANCIA;

void setup(){
  pinMode(TRIG, OUTPUT);
  pinMode(ECO, INPUT);
  pinMode(LED, OUTPUT);

  Serial.begin(9600);
}

void loop(){
  digitalWrite(TRIG, HIGH);
  delay(1);
  digitalWrite(TRIG, LOW);

  DURACION= pulseIn(ECO, HIGH);
  DISTANCIA= DURACION/58.2;

  Serial.println(DISTANCIA);
  delay(100);

  if (DISTANCIA<=20 && DISTANCIA>=0){
    digitalWrite(LED, HIGH);
    delay(100);
    digitalWrite(LED, LOW);
    digitalWrite(LED, HIGH);
    delay( DISTANCIA*10);
    digitalWrite(LED, LOW);

  

   

  



  }
  }