#include <Servo.h>

#define TRIG 2 
#define ECHO 3
#define SRVO 5
int distance;
Servo servo;


void setup() {
  pinMode(TRIG,OUTPUT) ;
  pinMode(ECHO,INPUT);
  servo.attach(SRVO);
  servo.write(90);


}

void loop() {
  digitalWrite(TRIG, LOW);
  delay(2);
  digitalWrite(TRIG, HIGH);
  delay(10);
  digitalWrite(TRIG, LOW);

  distance=pulseIn(ECHO,HIGH)/58;

  if(distance<=40){
    servo.write(0);
   delay(4000);

  }else{
    servo.write(90);
  }
  delay(1000);
}