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

// Define pins for Ultrasonic Sensor
#define TRIG_PIN 9
#define ECHO_PIN 10

// Define water level thresholds
#define SHALLOW_LEVEL 100  // 1 meter in centimeters
#define ADEQUATE_LEVEL 200  // 2 meters in centimeters
#define CAUTION_LEVEL 300  // 3 meters in centimeters

// LED pin
#define LED_SHALLOW 2
#define LED_ADEQUATE 3
#define LED_CAUTION 4
#define LED_DANGER 5

// Buzzer pin
#define BUZZER_PIN 6

// Initialize LCD
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Change the address (0x27) based on your LCD address

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.clear();
  pinMode(LED_SHALLOW, OUTPUT);
  pinMode(LED_ADEQUATE, OUTPUT);
  pinMode(LED_CAUTION, OUTPUT);
  pinMode(LED_DANGER, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  delay(1000);  // Delay 1 second

  // Send a ping to the ultrasonic sensor to get the distance
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  unsigned int distance = pulseIn(ECHO_PIN, HIGH) / 58;

  // Check the water level and display the appropriate status on the LCD
  if (distance >= 400) {
    lcd.setCursor(0, 0);
    lcd.print("Air Bahaya");
    digitalWrite(LED_DANGER, HIGH);
    tone(BUZZER_PIN, 2000);
  } else if (distance >= 300) {
    lcd.setCursor(0, 0);
    lcd.print("Air Waspada");
    digitalWrite(LED_CAUTION, HIGH);
    noTone(BUZZER_PIN);
  } else if (distance >= 200) {
    lcd.setCursor(0, 0);
    lcd.print("Air Cukup");
    digitalWrite(LED_ADEQUATE, HIGH);
    noTone(BUZZER_PIN);
  } else if (distance >= 100) {
    lcd.setCursor(0, 0);
    lcd.print("Air Dangkal");
    digitalWrite(LED_SHALLOW, HIGH);
    noTone(BUZZER_PIN);
  }

  // Turn off all LEDs
  digitalWrite(LED_SHALLOW, LOW);
  digitalWrite(LED_ADEQUATE, LOW);
  digitalWrite(LED_CAUTION, LOW);
  digitalWrite(LED_DANGER, LOW);
}