#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>

#define trigPin 9
#define echoPin 8
#define led 2

LiquidCrystal_I2C lcd(0x27, 16, 2);
Servo servo;

void setup() {
  lcd.begin(16, 2);
  lcd.init();
  lcd.setCursor(2, 0);
  lcd.backlight();
  lcd.print("  Hello!");
  lcd.setCursor(0, 1);
  lcd.print(" Microdigisoft");
  delay(5000);
  Serial.begin (9600);
  servo.attach(10);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(led, OUTPUT);
}

void loop() {
  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(3, 0);
  lcd.print("OBJECT");
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long distance = pulseIn(echoPin, HIGH) / 58.2;
  lcd.setCursor(0, 1);
  lcd.print ("distance:");
  if (distance <= 20) {
    Serial.print(distance);
    lcd.print(distance);
    lcd.print("cm");
    digitalWrite(led, HIGH);
    for (int pos = 180; pos > 1; pos--) {
      servo.write(pos);
      delay(5);
    }
    digitalWrite(led, HIGH);
    Serial.println("cm : LED is on ");
    delay(500);
    for (int pos = 0; pos < 180; pos++) {
      servo.write(pos);
      delay(5);
    }
  } else {
    Serial.print(distance);
    lcd.print(distance);
    lcd.print("cm");
    digitalWrite(led, LOW);
    Serial.println(" cm : LED is off ");
    delay(500);
    servo.write(0);
  }
}