#include <Servo.h>
Servo myservo;  
int potpin = 0;
int val;
void setup() {
  pinMode(6,OUTPUT);
  pinMode(7,INPUT);
  myservo.attach(9);
  Serial.begin(9600);


}
void loop() {
  digitalWrite(6, LOW);
  digitalWrite(6, HIGH);
  delayMicroseconds(10);
  digitalWrite(6, LOW);
  float timing  = pulseIn(7,HIGH);
  float personDistance = (timing*0.034)/2;
  if(personDistance<100){
     for (int pos = 0; pos <= 90; pos += 1) {
    myservo.write(pos);              
    delay(30);  
    if(pos == 90){
      Serial.print("pos =");
    Serial.println(pos);
      Serial.println("Turnstile gate is opened");
      delay(5000);
      
    }
  }
  }else if(personDistance>100){
  for (int pos = 90; pos >= 0; pos -= 1) {
    myservo.write(pos);            
    delay(30);
    if(pos == 0){
      Serial.print("pos =");
    Serial.println(pos);
      Serial.println("Turnstile gate is closed");
      delay(5000);
     
    }                      
  }
  }                        


}