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

#define LED_HIJAU 8
#define LED_KUNING 9
#define LED_MERAH 10
#define TRIG_PIN 7
#define ECHO_PIN 6
#define BUZZER 11


LiquidCrystal_I2C lcd(0x27, 16, 2); 
long duration;
int distance;
int waterLevel;   
bool isBuzzerOn;  

void setup() {
  pinMode(LED_HIJAU, OUTPUT);
  pinMode(LED_KUNING, OUTPUT);
  pinMode(LED_MERAH, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER, OUTPUT);

  lcd.begin(16, 2); 
  lcd.backlight();  
  lcd.print("Water Level");
  delay(2000); 
  isBuzzerOn = false;  
}

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

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

  if (distance < 5) {  
    waterLevel = 3; 
  } else if (distance >= 5 && distance <= 10) {  
    waterLevel = 2;  
  } else { 
    waterLevel = 1;  
  }

  lcd.clear();
  lcd.print("Water Level: ");
  if (waterLevel == 1) {
    lcd.print("Low"); 
    digitalWrite(BUZZER, LOW);  
    digitalWrite(LED_HIJAU, LOW);   
    digitalWrite(LED_KUNING, LOW);    
    digitalWrite(LED_MERAH, HIGH);      
    isBuzzerOn = false;
  } else if (waterLevel == 2) {
    lcd.print("Medium");  
    digitalWrite(BUZZER, LOW); 
    digitalWrite(LED_HIJAU, LOW);    
    digitalWrite(LED_KUNING, HIGH);  
    digitalWrite(LED_MERAH, LOW);          
    isBuzzerOn = false;
  } else if (waterLevel == 3) {
    lcd.print("High");  
    digitalWrite(LED_HIJAU, HIGH);    
    digitalWrite(LED_KUNING, LOW);   
    digitalWrite(LED_MERAH, LOW);     
    if (!isBuzzerOn) {                   
      digitalWrite(BUZZER, HIGH);    
      isBuzzerOn = true;
    }
  }

  lcd.setCursor(0, 1);  
  lcd.print("Dist: ");
  lcd.print(distance);
  lcd.print(" cm  "); 

  delay(500);  
}