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

const int trigPin = 2;
const int echoPin = 3;
const int buzzerPin = 4;
const int redPin = 5;
const int yellowPin = 6;
const int greenPin = 7;

long duration;
int distance;

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Inisialisasi LCD dengan alamat 0x27, 16 kolom dan 2 baris

void setup() {
  Serial.begin(9600);
  lcd.init();  // Inisialisasi LCD
  lcd.backlight();  // Nyalakan backlight LCD
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
}

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

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

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

  lcd.clear();  // Bersihkan layar LCD
  lcd.setCursor(0, 0);  // Pindahkan kursor ke kolom 0, baris 0
  lcd.print("Jarak: ");
  lcd.print(distance);
  lcd.print(" cm");

  if (distance > 100) {
    digitalWrite(redPin, LOW);    // Matikan LED merah
    digitalWrite(yellowPin, LOW);  // Matikan LED kuning
    digitalWrite(greenPin, HIGH);  // Hidupkan LED hijau
    lcd.setCursor(0, 1);
    lcd.print("Air Rendah   ");
    tone(buzzerPin, 200);          // Bunyi buzzer dengan frekuensi rendah
  } 
  else if (distance <= 100 && distance > 50) {
    digitalWrite(redPin, LOW);    // Matikan LED merah
    digitalWrite(yellowPin, HIGH); // Hidupkan LED kuning
    digitalWrite(greenPin, LOW);   // Matikan LED hijau
    lcd.setCursor(0, 1);
    lcd.print("Air Sedang  ");
    tone(buzzerPin, 500);          // Bunyi buzzer dengan frekuensi sedang
  } 
  else {
    digitalWrite(redPin, HIGH);   // Hidupkan LED merah
    digitalWrite(yellowPin, LOW); // Matikan LED kuning
    digitalWrite(greenPin, LOW);  // Matikan LED hijau
    lcd.setCursor(0, 1);
    lcd.print("Air Tinggi   ");
    tone(buzzerPin, 1000);        // Bunyi buzzer dengan frekuensi tinggi
  }

  delay(10000);
}