#include <Servo.h> 
int trigger_pin = 8;
int echo_pin = 9;
int buzzer_pin = 10;
int led1 = 11;
int led2 = 12;
Servo ServoHead;
int AservoPin = 3;
int time;

int distance;


void setup ( ) {
  Serial.begin (9600);
  pinMode (trigger_pin, OUTPUT);
  pinMode (echo_pin, INPUT);
  pinMode (buzzer_pin, OUTPUT);
  pinMode (led1, OUTPUT);
  pinMode (led2, OUTPUT);
  pinMode( AservoPin, OUTPUT);
  ServoHead.attach(AservoPin);

}

void loop ( ) {
 ServoHead.write(90);
  digitalWrite (trigger_pin, HIGH);
  delayMicroseconds (10);
  digitalWrite (trigger_pin, LOW);
  time = pulseIn (echo_pin, HIGH);
  digitalWrite (led1, LOW);
  digitalWrite (led2, LOW);
  digitalWrite (buzzer_pin, LOW);
    delay(1000); 
 distance = (time * 0.034) / 2;

  if (distance <= 10)

  {
    digitalWrite (buzzer_pin, HIGH);
    digitalWrite (led1, HIGH);
      ServoHead.write(0); 
    delay (1000);

  }

  else {

    digitalWrite (buzzer_pin, LOW);
 digitalWrite (led2, HIGH);
    delay (500);
  ServoHead.write(180); 
  }

}