Concept: The project aims to create a secure door lock system that uses a password entered through a keypad to activate a relay that unlocks the door. The system will display the status and prompts on a 16x2 LCD display.

Working Method:

1.            The keypad and 16x2 LCD display are connected to the Arduino board, along with the relay and lock mechanism.

2.            The user enters the correct password using the keypad, which is displayed on the LCD display.

3.            The Arduino board checks the entered password against a pre-set password stored in the program code.

4.            If the entered password matches the pre-set password, the Arduino board activates the relay connected to the lock mechanism, which unlocks the door.

5.            If the entered password does not match the pre-set password, the Arduino board displays an error message on the LCD display and does not activate the relay.

6.            The system also includes a reset button that clears any entered passwords and resets the LCD display.

7.            The system remains in the unlocked state until the user manually locks the door, at which point the relay is deactivated, and the door is locked.