     if (!is_hand) {
       is_hand = true;
       Serial.println("ON");
+      digitalWrite(led, HIGH);  
     }
     Serial.print("->");
     Serial.println(distance);

  // initialize serial communication at 9600 bits per second:
  Serial.begin(115200);
  Dist.begin(A0);
}

// the loop routine runs over and over again forever:

const int LOOP_LENGTH = 50;

int distance;
int led = 13;
boolean is_hand = false;
unsigned long time;
unsigned long loop_delay;
