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

#define Password_Lenght 7

LiquidCrystal_I2C lcd(0x27, 16, 2);
char Data[Password_Lenght]; // 6 is the number of chars it can hold + the null char = 7
char Master[Password_Lenght] = "123456";
byte data_count = 0, master_count = 0;
bool Pass_is_good;
char customKey;

const byte ROWS = 4;
const byte COLS = 4;

char keys[ROWS][COLS] = {
    {'1', '2', '3', '+'},
    {'4', '5', '6', '-'},
    {'7', '8', '9', '*'},
    {'C', '0', '=', '/'}
};

byte rowPins[ROWS] = {9, 8, 7, 6};
byte colPins[COLS] = {5, 4, 3, 2};

Keypad customKeypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS); // initialize an instance of class NewKeypad

void setup() {
    lcd.init(); // initialize the lcd
    lcd.backlight();
}

void loop() {
    lcd.setCursor(0, 0);
    lcd.print("Enter Password");
    customKey = customKeypad.getKey();
    
    if (customKey) {
        Data[data_count] = customKey;
        lcd.setCursor(data_count, 1);
        lcd.print(Data[data_count]);
        data_count++;
    }

    if (data_count == Password_Lenght - 1) {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Password is ");
        
        if (!strcmp(Data, Master))
            lcd.print("Good");
        else
            lcd.print("Bad");
        
        delay(5000);
        lcd.clear();
        clearData();
    }
}

void clearData() {
    while (data_count != 0) {
        Data[data_count--] = 0;
    }
    return;
} // End Program