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

#define TRIG_PIN 2      // TRIG ke pin 2
#define ECHO_PIN 3      // ECHO ke pin 3
#define LED_PIN 13      // LED ke pin 13

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Alamat I2C umum (ubah jika perlu)

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);

  lcd.init();           // Inisialisasi LCD
  lcd.backlight();      // Nyalakan backlight

  lcd.setCursor(0, 0);
  lcd.print("Mengukur Jarak");
  delay(1000);
  lcd.clear();
}

void loop() {
  // Trigger sensor
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Baca durasi echo
  long duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2;

  // Tampilkan jarak di LCD
  lcd.setCursor(0, 0);
  lcd.print("Jarak: ");
  lcd.print(distance, 1);
  lcd.print(" cm   ");  // Spasi untuk bersihkan sisa teks lama

  // Logika LED
  lcd.setCursor(0, 1);
  if (distance >= 50) {
    digitalWrite(LED_PIN, HIGH);
    lcd.print("LED: NYALA ");
  } else {
    digitalWrite(LED_PIN, LOW);
    lcd.print("LED: MATI  ");
  }

  delay(500);
}