#define Trig1 6
#define Echo1 5
#define Trig2 3
#define Echo2 2

#define Led 11


void setup() {
  // put your setup code here, to run once:
pinMode(Trig1,OUTPUT);
pinMode(Echo1,INPUT);
pinMode(Trig2,OUTPUT);
pinMode(Echo2,INPUT);
Serial.begin(115200);

}

int readPerson() {
  digitalWrite(Trig1, LOW);
  delayMicroseconds(2);
  digitalWrite(Trig1, HIGH);
  delayMicroseconds(10);
  digitalWrite(Trig1, LOW);
  int duration1 = pulseIn(Echo1, HIGH);
  int distance1= duration1 * 0.034 / 2;

  digitalWrite(Trig2, LOW);
  delayMicroseconds(2);
  digitalWrite(Trig2, HIGH);
  delayMicroseconds(10);
  digitalWrite(Trig2, LOW);
  int duration2 = pulseIn(Echo2, HIGH);
  int distance2= duration2 * 0.034 / 2;

  Serial.println(distance1 - distance2);

  return distance1 - distance2;
}




void loop() {
  // put your main code here, to run repeatedly:

int Differ = readPerson();
if (abs(Differ) >100 ){
    if (Differ >0){
      while (Differ >0 ){
        Differ = readPerson();
      }
      digitalWrite(Led,LOW);
    }

    else if (Differ <0){
      while (Differ < 0 ){
        Differ = readPerson();
      }
      digitalWrite(Led,HIGH);
    }
}
}