#include <Servo.h>
Servo servo1;

const int pingPin = 13;
int inPin = 12;

int l1=7;
int l2=6;
int l3=5;

void setup() {
Serial.begin(9600);

servo1.attach(11);

pinMode(l1, OUTPUT);
pinMode(l2, OUTPUT);
pinMode(l3, OUTPUT);
}
 
void loop() {
long duration, cm;
 
pinMode(pingPin,OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);

pinMode(inPin,INPUT);
duration = pulseIn(inPin, HIGH);
 
cm = microsecondsToCentimeters(duration);
 
Serial.print(cm);
Serial.print(" cm");
Serial.println();
delay(100);

if(cm <= 200) {
delay(500);
 servo1.write(90);
  digitalWrite(l1,1);
  digitalWrite(l3,1);
  digitalWrite(l2,0);

}

if(cm > 200) {
delay(500);
  servo1.write(0);
  digitalWrite(l2,1);
  digitalWrite(l3,0);
  digitalWrite(l1,0);
}

}
 
long microsecondsToCentimeters(long microseconds)

{return microseconds / 29 / 2;}