#include <Servo.h>   //servo library
Servo servo;     
int trigPin1 = 10;    
int echoPin1 = 11;   
int servoPin = 9;
int led= 10;
long duration, dist, average;   
long aver[3];   //array for average

// defines pins numbers
const int trigPin = 12;
const int echoPin = 13;
const int level4 = 8;
const int led1 = 2;
const int led2 = 3;
const int led3 = 4;
const int led4 = 5;
const int led5 = 6;
const int led6 = 7;
 
// defines variables
long duration;
int distance;
int safetyDistance;

void setup() {
   Serial.begin(9600);
    servo.attach(servoPin);  
    pinMode(trigPin1, OUTPUT);  
    pinMode(echoPin1, INPUT);  
    servo.write(0);         //close cap on power on
    delay(100);
    servo.detach(); 

 pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(echoPin, INPUT); // Sets the echoPin as an Input
pinMode(level4, OUTPUT);
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(led4, OUTPUT);
pinMode(led5, OUTPUT);
pinMode(led6, OUTPUT);  
Serial.begin(9600); // Starts the serial communication

}

void measure() {  
 digitalWrite(10,HIGH);
digitalWrite(trigPin1, LOW);
delayMicroseconds(5);
digitalWrite(trigPin1, HIGH);
delayMicroseconds(15);
digitalWrite(trigPin1, LOW);
pinMode(echoPin1, INPUT);
duration = pulseIn(echoPin1, HIGH);
dist = (duration/2) / 29.1;    //obtain distance

}

void loop() {
  for (int i=0;i<=2;i++) {   //average distance
    measure();               
   aver[i]=dist;            
    delay(10);              //delay between measurements
  }
 dist=(aver[0]+aver[1]+aver[2])/3;    

if ( dist<50 ) {
//Change distance as per your need
 servo.attach(servoPin);
  delay(1);
 servo.write(0);  
 delay(3000);       
 servo.write(150);    
 delay(1000);
 servo.detach();      
}
Serial.print(dist);

   // Clears the trigPin
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
 
// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
 
// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
 
// Calculating the distance
distance= duration*0.034/2;
 
safetyDistance = distance;
if (distance <=5)
{
  digitalWrite(level4, HIGH);
}
else
{
  digitalWrite(level4, LOW);
}
if (distance <=5)
{
  digitalWrite(led6, HIGH);
}
else
{
  digitalWrite(led6, LOW);
}
if (distance <=10)
{
  digitalWrite(led5, HIGH);
}
else
{
  digitalWrite(led5, LOW);
}
if (distance <=15)
{
  digitalWrite(led4, HIGH);
}
else
{
  digitalWrite(led4, LOW);
}
  
 if (distance <=20)
{
  digitalWrite(led3, HIGH);
}
else
{
  digitalWrite(led3, LOW);
}
  if (distance <=25)
{
  digitalWrite(led2, HIGH);
}
else
{
  digitalWrite(led2, LOW);
}
if (distance <=29)
{
  digitalWrite(led1, HIGH);
}
else
{
  digitalWrite(led1, LOW);
}
// Prints the distance on the Serial Monitor
Serial.print("Distance: ");
Serial.println(distance);

}