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Digital Code lock using AT89C2051

Tuesday, November 18th, 2008

Here is a project called ‘Digital Code Lock using AT89C2051′. LCD is used for display and a keyboard is used to input  the keys. This project source code is written in C. Both the C files and hex files are given for download.

A Brief Description:

This a simple project with efficient hacking prevention from Brute Force etc. The basic user lock is of 5 Digits and Master Lock is of 10 digits so its not easy for an intruder to break the lock unless you keep the code simple.

The input is taken from a 4×3 Keypad (please see the schematic for more information) and Display the user input on a 2×16 LCD. A pin is assigned as output for activating and deactivating the lock. For demonstration i have connected an LED to that pin.

From user side:
The user has two options either he/she can use its own 5 digit code or use the default 5 digit code. If user has to do setup his own code, then he has to enter “12345″ and press ‘#’. After this.. controller will ask for 10 Digit master password which is preprogrammed in the controller. Entering master lock, user can enter the new 5 digit code for the lock and press ‘#’ to save it.

Using the Keypad:
Keypad has 12 keys (4×3) starting from 1,2,3,4,5,6,7,8,9,*,0,# (please see the schematic for layout). Numeric keys are used for entering numbers. ‘*’ is used as the Cancel key and ‘#’ is used as the Enter key.

Circuit Diagram:

Circuit diagram of Digital Code lock using AT89C2051

Circuit diagram of Digital Code lock using AT89C2051

Download File Information:

  1. LCD.C – 4-Bit LCD Drivers
  2. LCD.H – LCD function prototypes and other declerations
  3. Lock.C – code for lock functioning
  4. LOCK.H – lock function declarations
  5. KEYPAD.C – Keypad drivers
  6. KEYPAD.H – Function declarations
  7. DELAY.C – Delay Functions
  8. DELAY.H – Function Prototypes only
  9. MAIN.C – Main function!
  10. Digital Code Lock Schematic – PDF file of orcad schematic

Download the source codes by clicking here

By Ajay Bhargav

http://rickeyworld.info

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Author Name :
Ranjith

Total : 23 Comments

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23 Responses to Digital Code lock using AT89C2051

  1. AMS
    March 14th, 2009 at 3:38 pm

    Hello Ajay Bhargav, which compiler did u use? I used SDCC but ur code seems to generate error. So cannot proceed for the asm files to be created.

  2. AVR
    July 20th, 2009 at 2:03 pm

    Nice project, but where do you store unlock key? I would put an EEPROM for key so you can change it programatically.

  3. emeka
    August 4th, 2009 at 12:00 am

    pls sir, from the files listed above, which one do I burn into the ucontroller

  4. emeka
    August 4th, 2009 at 12:03 am

    Pls Sir, from the files listed above, which one do I burn into the micro controller

  5. haider sharef mahde
    December 2nd, 2009 at 3:38 pm

    Digital Code Lock Schematic – PDF file of orcad schematic

  6. santosh
    January 17th, 2010 at 7:13 am

    you can burn this file emeka

    lock
    intel hex file
    6kb

  7. Aimbot Download
    January 18th, 2010 at 12:33 am

    A well written article, i’ve bookmarked it so I can look at it once i’m back from work.Thanks for writing it! :)

  8. irin
    February 6th, 2010 at 3:32 pm

    more information about digital code lock.

  9. thiru
    February 20th, 2010 at 1:27 pm

    nice useful for me
    how much cost this project is?

  10. Prakash
    August 3rd, 2010 at 4:51 pm

    fine

    good…
    thank u very much

  11. PATHIK PATEL
    August 20th, 2010 at 7:15 am

    Please Give Me The Program of AT89C2051. Plz it’s Ergent

  12. sahitya
    September 17th, 2010 at 6:47 pm

    sir please give me documentation for this project.

  13. jordan
    October 9th, 2010 at 7:10 pm

    asm file please hehe

  14. monika
    October 18th, 2010 at 5:24 pm

    pls give the microcontroller code for this code lock..

  15. mike
    November 2nd, 2010 at 6:52 pm

    hi monica
    here is the c code for microcontroller based digital code lock
    http://www.engineersgarage.com/microcontroller/8051projects/electronic-code-lock-with-password-using-at89c51

  16. Ayesha
    November 10th, 2010 at 11:48 pm

    which l.c.d u used in this kindly tell me the model and Vendor name of l.c.d or give me the data sheet if that L.C.D.
    Thnx
    Regards
    Ayesha

  17. Divyam Chhaya
    November 19th, 2010 at 1:49 pm

    Excellent !!!
    You’re genius….

  18. PHANI
    December 23rd, 2010 at 10:57 am

    please can you provide detailed information about code lock

  19. dhiru
    February 19th, 2011 at 12:29 am

    sir,i implementd on proteus but hex file shws enter lock code,but it dont
    take 12345 or anythng as a password plz help

  20. yemane
    May 16th, 2011 at 6:02 pm

    Sir,I need circuit design how to connect the keypad,and microcontroll 8051.
    thank you.

  21. sumeet
    September 11th, 2011 at 7:53 pm

    i want to make a digital clock with 3 displays of hours minutes and seconds using 8051 uc & 7 segment displays….so can u please tell me how to interface six seven segments with the microcontroller for this purpose?

  22. dhanashri suryawanshi
    September 21st, 2011 at 8:49 am

    Please sir, give me the more detail information,block diagram of digital code lock & keypad using AT89C2051.Plz it’s urgend.

  23. amit
    January 9th, 2012 at 9:45 pm

    sir,which file i must burn in microcontroller….????

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