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

const int buttonPin = 9;   // Push button pin
const int buzzerPin = 7;   // Buzzer
const int ledPin = 8;      // LED

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  pinMode(buttonPin, INPUT_PULLUP); // Use internal pull-up
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);

  lcd.begin(16, 2);
  lcd.backlight();

  Serial.begin(9600);
  lcd.setCursor(0, 0);
  lcd.print("Water Level Mon.");
}

void loop() {
  int buttonState = digitalRead(buttonPin);

  if (buttonState == LOW) {
    digitalWrite(buzzerPin, HIGH); // Buzzer ON
    digitalWrite(ledPin, HIGH);    // LED ON
    Serial.println("Water Level LOW! Please refill.");
    lcd.setCursor(0, 0);
    lcd.print("LOW! Refill tank ");
    lcd.setCursor(0, 1);
    lcd.print("Sim Btn Pressed  ");
  } else {
    digitalWrite(buzzerPin, LOW);  // Buzzer OFF
    digitalWrite(ledPin, LOW);     // LED OFF
    Serial.println("Water Level Normal.");
    lcd.setCursor(0, 0);
    lcd.print("Tank OK           ");
    lcd.setCursor(0, 1);
    lcd.print("Btn Released      ");
  }
  delay(500);
}