#include<Servo.h>
int servoPin=3;
int triggerPin=9;
int echoPin=8;
int travelTime;
float objectDistance;
float travelDistance;
int servoPos;
int opendledPin=7;
Servo myservo;
void setup() {
  myservo.attach(servoPin);
  pinMode(triggerPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(opendledPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  //trigger pluse genarating
  myservo.write(0);

  digitalWrite(triggerPin,LOW);
  delayMicroseconds(10);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  travelTime=pulseIn(echoPin,HIGH);
  travelDistance=(travelTime*765.*5280.*12.)/(3600.*1000000.);
  objectDistance=(2.54)*(travelDistance/2);
  Serial.println(objectDistance);
  //condition for open
  if(objectDistance<=40.0){
    myservo.write(90);
    digitalWrite(opendledPin, HIGH);
    Serial.println("Open");
    delay(5000);
    myservo.write(0);
    digitalWrite(opendledPin,LOW);
  }
delay(1000);
}