Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. An access control for doors forms a vital link in a security chain. The microcontroller based digital lock for Doors is an access control system that allows only authorized persons to access a restricted area.
An electronic lock or digital lock is a device which has an electronic control assembly attached to it. They are provided with an access control system. This system allows the user to unlock the device with a password. The password is entered by making use of a keypad. The user can also set his password to ensure better protection. The major components include a Keypad, LCD and the controller PIC16F877A. This article describes the making of an electronic code lock using the 16F877A microcontroller.
The system is fully controlled by the 8 bit microcontroller 16F877A which has a 8Kbytes of ROM for the program memory. The password is stored in the EPROM so that we can change it at any time. The system has a Keypad by which the password can be entered through it. When the entered password equals with the password stored in the memory then the relay gets on and so that the door is opened.
The code is built in a modular style to allow a user to find ways to modify project. In start the D Lock programs loads with a default code of "2345" format is *2345# which can be enter to unlock the door, the code cam be change by entering the master code in the format *23455#new 4 digit code. In this program i only display the result on LCD and lock will be placed at PORTA bit 0 where i put led for simulation.
A 4x3 matrix keypad and a 16x2 LCD have been used here. Keypad and LCD are very commonly used input & output devices, respectively. The password is stored in the system EEPROM.
While unlocking, if the entered password from keypad matches with the stored password, then the lock opens and a message is displayed on LCD. Also an output pin is made high to be used for further purpose..
As the program starts, wait for 5sec and press * string ‘Enter Password’ is displayed on LCD. The keypad is scanned for pressed digits one by one. Every time, row and column of the key pressed is detected and is displayed on LCD. After the four digits are entered, the user should press # to Confirm Password and again the input is taken through LCD. If the passwords do not match, a message is displayed to indicate ‘Access Denied’ otherwise the ‘Access Granted’ message.
Update 28-8-2013
1. Here two circuit are provided, the smaller one works only forsimulation and the larger one works only in real world( Problem
with Pull Down resistors)
2. Due to frequent Requests I have Uploaded the HEX(8Mhz Crystal) file of these project in Our Facebook Group-Click Here
Code
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7 comments:
One of the sadder aspects of living in society is the prevalence of theft. Intruders and would be burglars and thieves abound. And if anything of value is left unattended it is quite likely to be stolen. This is why locks of all kinds have come to exist.We'll always need the security of door locks as the first line of defense against such criminal acts.
electronic door lock
Proximity Credentials provides a higher level of security, more convenience and far greater functionality than a proximity card. As used on your business and in newer access control systems, smart credentials have the ability to manage access and many other functions much more securely.
electronic door lock
I cannot download the code you provided because of the downloading service asking to purchase membership first.
Your code works but still there is a problem. When the simulation starts lcd displays "Press *" and when the star is pressed. It says "Access Denied"
I truly appreciate for your efforts you to put in this article, this is educational and helpful. I truly enjoyed in reading this blog. Continue sharing and give us updates.
ip camera CCTV System & pbx phone system
This article is really helpful, thank you for giving us more knowledge! Introduce your side to the fingerprint khoa dien tu yale! thank you very much
This work is good. But has lot of loop holes
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