30-07-2012, 11:16 AM
EMBEDDED PASSWORD BASED SECURITY DOOR LOCK SYSTEM
A EMBEDDED PASSWORD.doc (Size: 636.5 KB / Downloads: 160)
ABSTRACT
AIM:
This project is described to design and develop a digital code lock using micro controller AT 89s52
DESCRIPTION:
Home/office security is top priority of all concerned. Today there are plenty of home/office security products to ensure your family’s security completely. Home/office security is the most significant one for every home/office owner either in an individual house or an apartment. For that different security systems are available. Those are smart cards, RFID’s, I-button, password and biometrics etc.
Access control is the ability to permit or deny the use of a particular resource by a particular entity. Access control system can be used in managing physical resources (such as a movie theater, to which only ticket holders should be admitted), logical resources (a bank account, with a limited number of people authorized to make a withdrawal), or digital resources, for these kinds of things.
The main idea of designing digital locking system is to provide many modern security features than mechanical lock; here key pad is used to enter the password. If that password matches to the password that was already stored in flash of the controller then the dc motor is activated and the door will be opened. If it does not matched then the buzzer is activated. Applications are entrance doors, car doors, bank lockers etc.
SELECTION OF MICROCONTROLLER:
As we know that there so many types of micro controller families that are available in the market.
Those are
1) 8051 Family
2) AVR microcontroller Family
3) PIC microcontroller Family
4) ARM Family
Basic 8051 family is enough for our application; hence we are not concentrating on higher end controller families.But still we selected AT89S52 controller because of inbuilt ISP (in system programmer) option.
There are minimum six requirements for proper operation of microcontroller.
Those are:
1) power supply section
2) pull-ups for ports (it is must for PORT0)
3) Reset circuit
4) Crystal circuit
5) ISP circuit (for program dumping)
6) EA/VPP pin is connected to Vcc.
PORT0 is open collector that’s why we are using pull-up resistor which makes PORT0 as an I/O port. Reset circuit is used to reset the microcontroller. Crystal circuit is used for the microcontroller for timing pluses. In this project we are not using external memory that’s why EA/VPP pin in the microcontroller is connected to Vcc that indicates internal memory is used for this application.
CIRCUIT OPERATION:
Here after giving the power supply it will display to open the door or to close the door to close the door we have to press the ‘*’ and for opening the door ‘#’ has to pressed. Program will not continue till we press ‘*’ or ’#’.after that it will ask to enter the password and instead of displaying the password we are displaying ‘*’ on the LCD. If password is matched according to the command door will open/close. For opening and closing the door in this project we connected DC motors and we are rotating forward direction for opening the door and reverse direction for closing the door. If password not matched buzzer will start .This process will continue .Here in this project we kept password as 160 we can change it through program and changed program we have to dump it in to the microcontroller.