const int TRIG = D9;
const int ECHO = D10;
const int MY_LED = 8;
void setup() {
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(MY_LED, OUTPUT);
  digitalWrite(MY_LED, LOW); // LED off at start
}
void loop() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  long duration = pulseIn(ECHO, HIGH);
  float distanceCM = (duration * 0.034) / 2;
  if (distanceCM < 10) {
    digitalWrite(MY_LED, HIGH); // Hand close — LED ON
  } else {
    digitalWrite(MY_LED, LOW);  // No hand — LED OFF
  }
  delay(100);
}