Design And Construction Of A Digital Door Code Lock System Using Computer Interface

Project and Seminar Material For Electrical Electronics Engineering EEE

Project and Seminar Material For Electrical Electronics Engineering EEE


This project topic titled digital door code lock system using computer interface is a door security system for a door having an electrical, digital and computer actuated lock.

This door lock is controlled by a code lock controller having a correct code memory. Code lock as a mechanical device for securing a door or object so that it cannot be opened except by a series of manipulations that can be carried not only by a person knowing the secret or code”.

This project also tells the characteristics of each component that is used in the construction and operation of this digital door lock system and then the recommendation and conclusion of the work.

Chapter One

1.0 Introduction

A digital door code lock system using computer interface makes use of “code lock as a digital, electrical and mechanical device. It is designed for low usage application such as staff only area, information technology (IT) rooms, office doors, toilets, bank doors and store cupboards.

The unit is fully reversible, simple to fit stays locked until correct code is entered, code easily changed, over 8000 codes to choose from suitable for entering use and doors up to 55mm thick.

It could be used for locking the door, the bike, the fence and so on. It is a simple and secure method of locking without having to resort to the use of keys.

The digital door is a practical and code locking solution, ideal for commercial or residential premises where only a few internal doors need securing. It removes the need for keys, taking away the hassle and cost of copying or replacing lost ones.

Doors fitted with a co-door are opened by typing in a code, minimizing the risk of unwanted visitors gaining access to a restricted area, without imprinting the daily activities of tenants or staff.

This digital door incorporates an electronic code cock, a mechanical locking device and a power unit in the same housing and alternations to the door frame.

The door slides itself when the correct code is entered (2,4,6,8) and closes when a switch is pressed OFF. It provides user with a secure, convenient and cost effective way of locking doors.

The target or major aim of the digitally controlled door is to increase reliability and confidence limits by offering access to certified persons belonging to the set having the knowledge of the codes or permitted by the computerized interface.

It is therefore worthy of consideration as it is consistent with recent global realities where recession and global melt down has increased crime rates and hence the more need for security consciousness.

Constituent Circuits

The digitally coded door can be organized into:

  • The flip flop section.
  • Mono stable section
  • Manual close section
  • Computer interface section.

Basic Observed Configuration

There exist certain variations which is a product of the different combinations and the relationship between one of these segments and the other. Some of the variations can be noted as follows:

  1. A combination which is opened by a single button push and automatically closed after a specified time lag with default buttons e.g. banks.
  2. A combination of single push button to open and a single push button to close.
  3. A combination of multiple push buttons to open and multiple push buttons to close.
  4. A combination of a multiple push button to open and a single push button to close.

All of the above variations can be programmed with a computer Interface which makes this particular project unique in nature.

1.1 Significance Of The Study

The significance is inherent in the importance of security. After life is the major gift from the divine or supernatural men, the most primary obligation of man as his own role in appreciation of the gift of the divine, is security be it of life or extended to property.

Any effort therefore to ensure security is the compulsory role of man to appreciate the divine hence the relevance of this project: digitally coded door with computer interface.

This project targets to eliminate all or most of the problems associated with the use of manually operated doors and improves the confidence and convenience of the user. It equally targets to reduce all factors leading to insecurity of lives and properties. Thus the significance of this project is;

  1. To provide security in such a way that only authorized persons with the knowledge of the code can have entry access.
  2. To reduce labour as it eliminates the option of a member
    of the closed set waiting for another who might stand on the door and open close doors.
  3. It is more convenience to the user as unpermitted persons don’t interrupt his movement.
  4. It does not require a high voltage to drive it and is as such easily handled due to its less harmful nature.
  5. This project incorporates a logic system that switches off the rotating motor and prevents it from wear and tear which arises when it runs permanently.
  6. The user has the liberty of taking his/her time to perform operations or use the access until the reverse button is pressed unlike the banks where after time lag the door shuts.

Disadvantages Of This Project

  1. A visitor coming to the house must call before having access to the door.
  2. If used on a cupboard, where documents are kept, when the person with the code dies will lead to breaking the cupboard.
  3. When drunk and code forgotten, you can never have access to it.
  4. When there is power failure access to the door will be restricted.

1.2 Scope Of Study

1. The scope of this project covers the construction of a digitally coded door with computer interface.
2. There is no emphasis on any display system hence no display system is involved in this project.
3. The voltage rating for each component did not exceed the stipulated values in order to avoid damaging the circuit.
4. The scope therefore covers the above mentioned points coupled with the understanding of the working principles of the various four (4) basic observed configurations.
5. It strives to understand the working principles of the industrial components and their characteristics combinational activities applied to the project.

1.3 Definition Of Terms

The term digital coded door with computer interface could be simplified as the use of codes and computer to control the opening and closing processes of the door system of offices, homes, gates etc.

The operation of input codes is controlled by four (4) different flip flop integrated circuits that compares or evaluates the different four (4) input codes for opening the door system. The integrated circuit value is CD4013 which is used as bi stable multi vibrator.

The timing of the circuit is the period of motor rotation at a particular time is controlled by the mono stable section endorsed by the NE555 integrated circuits and determined by the equation T = 1+RC.

The buffer circuit maintains a constant voltage.

Chapter Five


The design of this project coded door with computer interface is a worthwhile project as it avails the executor with theoretical knowledge of the operation of digital codes.

In this project in particular the use of the four integrated circuits to accept the four different input codes is a worthwhile experience too. Most importantly the practical knowledge of the assembling of the different components and understanding their different roles individually and in different combination is a life experience.

Initially when this project mandate was given, the mere mention of complete interface was terrorizing but with the continuous research under supervision and with the issue and concept of computer interface was climatified. The entire project therefore combined the work and benefit of the code lock system as in automatic coded safe with the gains of the computer to achieve a great result.

When the proper codes are keyed in properly, they are accepted and the relays trigger to energies the motor that slides the door.

Consequently the computer can be used to issue an open and close command to the door with another final one way button. Just for closing the system. The above are synchronized and package carefully to meet specification and compete favorably in the market.

Importance Of The Design

  1. The automatic digitally coded door has a free float system; this permits the user to enter the apartment without any increased resistance to the door operation.
  2. This design reduce to the bearest minimum the possibility of thief, and all sorts of break and entry into our homes
  3. This design could also be applicable not only in our apartments but also in the opening and closing of banks vaults with little or no motivation.
  4. The design is portable and therefore can be removed and re-installed in another door until as need arises.

Get Complete Project Material

5,000 5000

The Complete Material Will Be Sent to You in Just 2 Steps

Quick & Simple…

Step One Purchase

Make Payment (Through Transfer) of ₦5,000 to the Account Below

Zenith BankAcc No: 1225513212
Samphina Academy
Current Account

Or CLICK HERE To Pay With Debit Card

CLICK HERE To Purchase Material ($15)

Step Two Purchase

Send the Following Details on WhatsApp ( 08143831497) After Payment

  1. Payment Details

  2. TOPIC: Design And Construction Of A Digital Door Code Lock System Using Computer Interface

The Complete Material Will Be Sent To You On WhatsApp After Receiving Your Details
T & C Apply

  Contact Our Help Desk

Need a Different Topic? Perform a Quick Search

List of Related Works

Click on Any Topic to Preview the Content

Samphina Academy

Samphina Academy is an Online Educational Resource Center that is aimed at providing students with quality information and materials to aid them in succeeding in their academic pursuit.