#include <LiquidCrystal_I2C.h>

// Inisialisasi LCD dengan alamat I2C dan ukuran 16x2
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Deklarasi pin LED
int ledMerah = 6;
int ledBiru = 7;
int ledJingga = 5;

void setup() {
  pinMode(3, OUTPUT); // Pin Trig
  pinMode(2, INPUT);  // Pin Echo
  pinMode(ledMerah, OUTPUT);
  pinMode(ledBiru, OUTPUT);
  pinMode(ledJingga, OUTPUT);
  
  lcd.init();
  lcd.backlight();
  lcd.clear();
}

void loop() {
  digitalWrite(3, LOW);
  delayMicroseconds(2);
  digitalWrite(3, HIGH);
  delayMicroseconds(10);
  digitalWrite(3, LOW);

  int waktu = pulseIn(2, HIGH);
  float jarak = waktu * 0.034 / 2;

  lcd.setCursor(0, 0);
  lcd.print("Jarak: ");
  lcd.print(jarak);
  lcd.print(" CM ");

  // Reset semua LED
  digitalWrite(ledMerah, LOW);
  digitalWrite(ledBiru, LOW);
  digitalWrite(ledJingga, LOW);
  
  lcd.setCursor(0, 1); // Pindah ke baris kedua

  if (jarak < 50) {
    digitalWrite(ledMerah, HIGH);
    lcd.print("Bahaya      ");
  } else if (jarak < 150) {
    digitalWrite(ledBiru, HIGH);
    lcd.print("Waspada     ");
  } else {
    digitalWrite(ledJingga, HIGH);
    lcd.print("Aman mi     ");
  }
  delay(100);
}