#define BUZZER_PIN 3  // GPIO pin connected to the buzzer
#include <Keypad.h>
//#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd_1(0x27, 16, 2);  
const byte ROW_NUM = 4; // Number of rows in the keypad
const byte COL_NUM = 4; // Number of columns in the keypad

// Define the keymap for your keypad
char keys[ROW_NUM][COL_NUM] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

// Define the row and column pin numbers for the keypad
byte rowPins[ROW_NUM] = {6, 7, 8, 9};  // Pin numbers connected to the keypad rows
byte colPins[COL_NUM] = {10, 11, 12, 13};  // Pin numbers connected to the keypad columns

// Create an instance of the Keypad library
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROW_NUM, COL_NUM);

void setup() {
  pinMode(4,OUTPUT);
  pinMode(2,OUTPUT);
  Serial.begin(9600);
  lcd_1.begin(16, 2);
  lcd_1.backlight();
  pinMode(BUZZER_PIN, OUTPUT);
  // Display a welcome message
  lcd_1.setCursor(0, 0);
  lcd_1.print("Enter key:");
  // Initialize the 7-segment display pins as output

  
}
int i=0;
int z;
String pass="";
void loop() {
  String pass = "";  // Reset password each time the loop starts
  int i = 0;         // Cursor position on the LCD for this password attempt

  while (true) {
    char key = keypad.getKey();  // Read the pressed key from the keypad
    digitalWrite(2, LOW);
    if (key) {
      lcd_1.setCursor(i, 1);
      lcd_1.print(key);
      i++;                // Move to the next position for the next character
      pass += key;        // Append the key to the password
    }
    
    // Display the entered password so far

    // Check if the password has been entered fully
    if (pass.length() == 6) {
      if (pass == "ABCD12") {
        // Correct password actions
        digitalWrite(4, HIGH);
        lcd_1.clear();
        lcd_1.setCursor(0, 0);
        lcd_1.print("CORRECT");
        lcd_1.setCursor(0, 1);
        lcd_1.print("key");
        tone(BUZZER_PIN, 500);  // Play a 500 Hz tone on the buzzer
        delay(500);             // Wait for 0.5 seconds
        noTone(BUZZER_PIN);     // Stop the tone
        delay(500);

        // Stop the loop to prevent further code execution after the correct password
        while (true);  // Infinite loop to halt further execution

      } else {
        // Incorrect password actions
        digitalWrite(2, HIGH);
        lcd_1.clear();
        lcd_1.setCursor(0, 0);
        lcd_1.print("WRONG");
        lcd_1.setCursor(0, 1);
        lcd_1.print("key");
        tone(BUZZER_PIN, 1000); // Play a higher tone for incorrect password
        delay(500);
        noTone(BUZZER_PIN);
        delay(500);
        
        // Clear LCD and reset for another attempt
        lcd_1.clear();
        lcd_1.print("Enter key:");
        pass = "";              // Reset password
        i = 0;                  // Reset LCD cursor position
      }
    }
  }
}