Here, we build an electronic code lock system using Arduino, which provides control to operate the load.This output load can be a lamp or any other mechanical or electrical load. Such an automatic lock system contains of electronic control assembly, which manages the output load through a password.One of the prominent features of these new lock systems is their clearness and high efficiency. These techniques are a combination of mechanical and electronic components and are highly intelligent. Traditional lock using mechanical lock and key mechanism are being restored by new techniques of locking system.In this lesson we will talk about the principles of door locking, circuit diagram and working of this project. The purpose is to secure with door lock with the help of password. Hello Friends! In this project I will design a simple Password Based Door Lock using Arduino.