Arduino Simple Lock System

//feel free to contact
//sreeramaj53@gmail.com
//www,youtube.com/ZenoModiff

#include <Wire.h>
#include <Keypad.h>                 
#include <LiquidCrystal_I2C.h>
#include<EEPROM.h>
LiquidCrystal_I2C liquid_crystal_display(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);

char password[4];

char initial_password[4],new_password[4];

int i=0;

int Led_pin = 12;

char key_pressed=0;

const byte rows = 4; 
const byte columns = 4; 

char hexaKeys[rows][columns] = {

{'1','2','3','A'},

{'4','5','6','B'},

{'7','8','9','C'},

{'*','0','#','D'}

};

byte row_pins[rows] = {5,4,3,2};

byte column_pins[columns] = {6,7,8,9};   

Keypad keypad_key = Keypad( makeKeymap(hexaKeys), row_pins, column_pins, rows, columns);

byte locked[8] = { 
  B01110,
  B01010,
  B01010,
  B01010,
  B11111,
  B11111,
  B11111,
  B00000,
};
byte unlocked[8] = { 
  B01110,
  B01010,
  B00010,
  B00010,
  B11111,
  B11111,
  B11111,
  B00000,
};

byte key[8] = {
  B11111,
  B10001,
  B10001,
  B11111,
  B00100,
  B01100,
  B00100,
  B01100
};

void setup()

{

  pinMode(Led_pin, OUTPUT);

  liquid_crystal_display.begin(16,2);
  liquid_crystal_display.createChar(0, locked);
  liquid_crystal_display.createChar(1, unlocked);
  liquid_crystal_display.createChar(2, key);

  liquid_crystal_display.setCursor(1,0);

  liquid_crystal_display.print("  ZenoModiff");

  liquid_crystal_display.setCursor(0,1);

  liquid_crystal_display.write(byte(2));
  
  liquid_crystal_display.print(" Arduino Lock ");

  liquid_crystal_display.write(byte(2));

  delay(2000);

  liquid_crystal_display.clear();

  liquid_crystal_display.print(" Enter Password");

  liquid_crystal_display.setCursor(0,1);

  initialpassword();

}




void loop()

{

  digitalWrite(Led_pin, LOW);

  key_pressed = keypad_key.getKey();

  if(key_pressed=='#')

    change();

  if (key_pressed)

  {

    password[i++]=key_pressed;

    liquid_crystal_display.print(key_pressed);

      }

  if(i==4)

  {

    delay(200);

    for(int j=0;j<4;j++)

      initial_password[j]=EEPROM.read(j);

    if(!(strncmp(password, initial_password,4)))

    {

      liquid_crystal_display.clear();

      liquid_crystal_display.print(" Pass Accepted");

      liquid_crystal_display.setCursor(7,1);

      liquid_crystal_display.write(byte(1));

     
      digitalWrite(Led_pin, HIGH);

      delay(2000);

      liquid_crystal_display.clear();

      liquid_crystal_display.setCursor(0,1);

      liquid_crystal_display.print("Pres # to change");

      delay(2000);

      liquid_crystal_display.clear();

      liquid_crystal_display.print(" Enter Password:");

      liquid_crystal_display.setCursor(0,1);

      i=0;




    }

    else

    {

      digitalWrite(Led_pin, LOW);




      liquid_crystal_display.clear();

      liquid_crystal_display.print(" Wrong Password");

      liquid_crystal_display.setCursor(7,1);

      liquid_crystal_display.write(byte(0));
      
      delay(2000);

      liquid_crystal_display.clear();

      liquid_crystal_display.setCursor(0,1);

      liquid_crystal_display.print("Pres # to change");

      delay(2000);

      liquid_crystal_display.clear();

      liquid_crystal_display.print(" Enter Password:");

      liquid_crystal_display.setCursor(0,1);

      i=0;





    }

  }

}

void change()

{

  int j=0;

  liquid_crystal_display.clear();

  liquid_crystal_display.print("Current Password");

  liquid_crystal_display.setCursor(0,1);

  while(j<4)

  {

    char key=keypad_key.getKey();

    if(key)

    {

      new_password[j++]=key;

      liquid_crystal_display.print(key);

       

    }

    key=0;

  }

  delay(500);




  if((strncmp(new_password, initial_password, 4)))

  {

    liquid_crystal_display.clear();

    liquid_crystal_display.print("Wrong Password");

    liquid_crystal_display.setCursor(0,1);

    liquid_crystal_display.print("Try Again");

    delay(1000);

  }

  else

  {

    j=0;

    liquid_crystal_display.clear();

    liquid_crystal_display.print("New Password:");

    liquid_crystal_display.setCursor(0,1);

    while(j<4)

    {

      char key=keypad_key.getKey();

      if(key)

      {

        initial_password[j]=key;

        liquid_crystal_display.print(key);

        EEPROM.write(j,key);

        j++;

     

      }

    }

    liquid_crystal_display.print("Pass Changed");

    delay(1000);

  }

  liquid_crystal_display.clear();

  liquid_crystal_display.print("Enter Password");

  liquid_crystal_display.setCursor(0,1);

  key_pressed=0;

}




void initialpassword(){

  for(int j=0;j<4;j++)

    EEPROM.write(j, j+49);

  for(int j=0;j<4;j++)

    initial_password[j]=EEPROM.read(j);

}


 //    Coded With <3 ZenoModiff 
 //    sreeramzeno@gmail.com
 //    www.youtube.com/ZenoModiff