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

LiquidCrystal_I2C lcd(0x27, 20, 4);  // Alamat I2C untuk LCD 20x4

const int trigPin = 5; // Pin Trigger HC-SR04
const int echoPin = 18; // Pin Echo HC-SR04
const int greenLedPin = 4; // Pin LED Hijau
const int yellowLedPin = 2; // Pin LED Kuning
const int redLedPin = 15; // Pin LED Merah

void setup() {
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(yellowLedPin, OUTPUT);
  pinMode(redLedPin, OUTPUT);

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

void loop() {
  long duration, distance;
  
  // Mengirimkan pulsa ultrasonik
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Menerima waktu pulsa kembali
  duration = pulseIn(echoPin, HIGH);
  
  // Menghitung jarak
  distance = (duration * 0.034) / 2;

  // Menampilkan jarak di Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Menampilkan teks di LCD
  lcd.setCursor(0, 0);
  lcd.print("SENSOR BANJIR");
  lcd.setCursor(0, 1);
  lcd.print("POLJAN CIPARAY");
  lcd.setCursor(0, 2);
  lcd.print("CITARUM");
  lcd.setCursor(0, 3);

  // Menyalakan LED berdasarkan jarak
  if (distance >= 180) {
    digitalWrite(greenLedPin, HIGH);
    digitalWrite(yellowLedPin, LOW);
    digitalWrite(redLedPin, LOW);
    lcd.setCursor(0, 3);
    lcd.print("Status: Aman      ");
  } else if (distance >= 150 && distance < 180) {
    digitalWrite(greenLedPin, LOW);
    digitalWrite(yellowLedPin, HIGH);
    digitalWrite(redLedPin, LOW);
    lcd.setCursor(0, 3);
    lcd.print("Status: Siaga 1    ");
  } else if (distance >= 120 && distance < 150) {
    digitalWrite(greenLedPin, LOW);
    digitalWrite(yellowLedPin, HIGH); // LED kuning menyala
    digitalWrite(redLedPin, LOW);
    lcd.setCursor(0, 3);
    lcd.print("Status: Siaga 2    ");
  } else {
    digitalWrite(greenLedPin, LOW);
    digitalWrite(yellowLedPin, LOW);
    digitalWrite(redLedPin, HIGH); // LED merah menyala
    lcd.setCursor(0, 3);
    lcd.print("Status: Siaga 3    ");
  }
  
  delay(1000);
}