#include <Servo.h>
Servo S;
#define echoPin 2
#define trigPin 3
long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  S.attach(9);
  S.write(0);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2; 
  if ((distance > 0)&&(distance <= 10))
  {
    S.write(180);
    delay(3000);
    S.write(0);
  }
}