///you need to set this values depends on your room
int NORMAL_DISTANCE = ###;
int THRESHOLD_DISTANCE =  ##;

const int trigPin = 9;
const int echoPin = 10;
long duration;
int distanceCm, distanceInch;
int dis() {
  digitalWrite(A2, LOW);
  delayMicroseconds(2);
  digitalWrite(A2, HIGH);
  delayMicroseconds(10);
  digitalWrite(A2, LOW);
  duration = pulseIn(A1, HIGH);
  distanceCm= duration*0.034/2;
  distanceInch = duration*0.0133/2;
  return distanceCm;
}