#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

#define ECHO_PIN 1
#define TRIG_PIN 2
#define BUZZER 3

#define SOUND_SPEED 0.034 // Kecepatan suara dalam cm/us

long duration;
float distanceCm;
float distanceM;

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER, OUTPUT);
  lcd.init();
  lcd.backlight();
  Serial.begin(9600);
}

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

  // Mengukur waktu pantulan
  duration = pulseIn(ECHO_PIN, HIGH);
  
  // Menghitung jarak dalam cm dan m
  distanceCm = (duration * SOUND_SPEED / 2);
  distanceM = distanceCm / 100;

  // Tampilkan jarak di LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Kedalaman: ");
  lcd.setCursor(11, 0);
  lcd.print(distanceM, 2);  // Menampilkan dua angka di belakang koma
  lcd.setCursor(15, 0);
  lcd.print("M");  

  // Menampilkan status dan mengontrol buzzer
  lcd.setCursor(0, 1);
  if (distanceM < 0.76) {
    lcd.print("Status: Aman   ");
    noTone(BUZZER); // Matikan buzzer jika aman
  } 
  else if (distanceM >= 0.76 && distanceM <= 1.50) {
    lcd.print("Status: Waspada");
    noTone(BUZZER); // Matikan buzzer jika waspada
  } 
  else {
    lcd.print("Status: Bahaya ");
    tone(BUZZER, 100); // Frekuensi 1000 Hz
  }

  delay(1100); // Jeda sebelum pengukuran ulang
}