This document describes the design and construction of a password-based digital door lock system. It lists the objectives as developing an intelligent lock that opens with the correct password and closes automatically after 5 seconds. It also aims to offer safe and secure access by keeping the door closed if the wrong password is entered and triggering a buzzer. The key hardware components needed are described as a 4x4 keypad, LCD, servo motor, Arduino Uno, ATmega328 microcontroller, power supply, breadboard, resistors, potentiometer and buzzer. Diagrams of the circuit and block are also provided, along with a flowchart of the working process.

1. Design and construction of
Password Base Digital Door Lock
Prepared By
Md. Rezaul Karim Palash
B.Sc. In EEE
Daffodil International University
Email: erkpalash@gmail.com

2. CONTENTS
 Introduction
Objectives
 Hardware Requirements
 Circuit Diagram
Working Process Of Our Circuit
 Flowchart Diagram of proposed System
Video Presentation
Advantages
Disadvantages
Limitations
Applications
Future Scope
Conclusion erkpalash@gmail.com

3. INTRODUCTION
The aim of our project is to develop “Password Based Door Lock System”.
This is a kind of microcontroller based projects, which created a secure access
for a door which needs a password to open the door.
The system will be used in places where we need more security.
It can also be used in door, lockers, offices, main gate of house, ATM etc.
erkpalash@gmail.com

4. OBJECTIVES
To develop an intelligent, Whenever the right password will be received, the
controller will accordingly give instruction to servo motor. Servo motor will perform
the action on door unlocking.
The door will close automatically after 5 seconds.
To offer safe and secure, if the password is wrong, then door would remain closed,
denying access to the person.
If give wrong password the buzzer will sound.
erkpalash@gmail.com

5. HARDWARE REQUIREMENTS
4×4 keypad
LCD
Servo Motor
Arduino Uno
Microcontroller ATmega328
Power Supply
Breadboard
1KΩ, 220Ω Resistor
10KΩ Potentiometer
Buzzer
Connecting wires
erkpalash@gmail.com

6. POWER SUPPLY UNIT
CIRCUIT DIAGRSM
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7. MICROCONTROLLER INTERFACE
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8. BLOCK DIAGRAM
POWER SUPPLY
LCD
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9. FLOW CHART
START
INITIALIZE:
•MICRO-CONTROLLER
•LCD & KEYPAD
BUZZER ON
ENTER PASSWORD
IS
PASSWORD
ICORRECT?
EXTRACTION
OF DETAILS
ServoOperates
END
Servo Revers
Yes
No
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10. MAIN COMPONENTS
Microcontroller AT mega 328
Servo Motor
4*4 Keypad
16*2 LCDBuzzer
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11. IMPLEMENTATION
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12.  Arduino providers are almost available in our country.
 We can control the home appliances by protecting with password from
unwanted hazards.
 We can set password as we wish.
 It is cheaper when compared to other type of automation system.
 It is more effective when compared to other type of automation system.
 It is easy to change to the systems action according to change in situation.
ADVANTAGES
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13.  It works only when DC power supply has given.
If you forget the password it is not possible to open the door.
DISADVANTAGES
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14. APPLICATION
This simple circuit can be used at residential places to ensure better safety.
It can be used at organizations to ensure authorized access to highly secured
places.
With a slight modification this Project can be used to control the switching of
loads through password.
erkpalash@gmail.com

15. FUTURE SCOPE
We can send this data to a remote location using mobile or internet.
We can add fingerprint sensor so entry will be allowed for the authorized person
using their fingerprints.
We can add fire and LPG sensors so that, the doors will automatically open.
erkpalash@gmail.com

16. THANKS TO ALL