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

// Inisialisasi objek LCD
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Inisialisasi pin sensor ultrasonik
const int trigPin = 9;
const int echoPin = 10;

// Inisialisasi pin LED
const int led1 = 2;
const int led2 = 3;
const int led3 = 4;
const int led4 = 5;

void setup() {
  // Inisialisasi pin-mode
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);

  // Inisialisasi LCD
  lcd.begin(16, 2);
  lcd.print("Jarak: ");
}

void loop() {
  // Mengirim pulse ultrasonik
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Menerima hasil echo
  long duration = pulseIn(echoPin, HIGH);

  // Menghitung jarak dalam centimeter
  int distance = duration * 0.034 / 2;

  // Menampilkan hasil di LCD
  lcd.setCursor(7, 0);
  lcd.print("    "); // Membersihkan karakter sebelumnya
  lcd.setCursor(7, 0);
  lcd.print(distance);
  lcd.print(" cm");

  // Mengaktifkan LED berdasarkan jarak
  updateLEDs(distance);

  delay(500); // Delay untuk memperlambat pembacaan
}

void updateLEDs(int distance) {
  if (distance < 50) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
  } else if (distance >= 50 && distance < 150) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
  } else if (distance >= 150 && distance < 250) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, LOW);
  } else if (distance >= 250 && distance < 350) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
  } else {
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
  }
}