A Mini Ultrason Radar using ARDUINO UNO

#include <Servo.h>

const int trigPin = 8;
const int echoPin = 9;
const int ledPin = 7; //  LED connected to pin 7

long duration;
int distance;
Servo myServo;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT); //  Set LED pin as output
  Serial.begin(9600);
  myServo.attach(10);
}

void loop() {
  for (int i = 15; i <= 165; i++) {
    myServo.write(i);
    delay(30);
    distance = calculateDistance();

    //  Check distance and light LED if object is detected
    if (distance <= 20) {
      digitalWrite(ledPin, HIGH); // Turn on LED
    } else {
      digitalWrite(ledPin, LOW);  // Turn off LED
    }

    Serial.print(i);
    Serial.print(",");
    Serial.print(distance);
    Serial.print(".");
  }

  for (int i = 165; i > 15; i--) {
    myServo.write(i);
    delay(30);
    distance = calculateDistance();

    if (distance <= 20) {
      digitalWrite(ledPin, HIGH); // Turn on LED
    } else {
      digitalWrite(ledPin, LOW);  // Turn off LED
    }

    Serial.print(i);
    Serial.print(",");
    Serial.print(distance);
    Serial.print(".");
  }
}

int calculateDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

  return distance;
}