#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

const int TRIG_PIN  = 6;  
const int ECHO_PIN  = 7;  

const int SERVO_PIN = 9;
Servo servo;

float duration_us, distance_cm;

void setup() {
  Serial.begin (9600); 
  lcd.init();
  lcd.backlight();

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  servo.attach(SERVO_PIN);
  servo.write(0);

}

void loop() {

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

  duration_us = pulseIn(ECHO_PIN, HIGH);
  distance_cm = 0.017 * duration_us;

  Serial.print("distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");


  lcd.setCursor(0, 0);
  Serial.print("uitr : ");

  lcd.setCursor(2, 1);
  lcd.print(distance_cm); 
  
  lcd.setCursor(14, 1);
  lcd.print("cm  "); 
  delay(200);
  
  if(distance_cm >= 100 && distance_cm <= 100 ){
    servo.write(180);
  }

  else{
    servo.write(90);
  }
}