Introduction:-

In Electronics Access control system , we will control the door using password protection. In thisd project we will control  it using microcontroller 89C051. we will use key matrix to enter data, if entered data will match with stored data in microcontrolller, then only it will allow the door to open , otherwise it will remain locked.

The main key in this project is coding  of password.we will use stepper motor to open the door , so that door will open step by step.

We will use LCD display to show the entered password.

It will also show the entered password match with stored password, if the password will match then it will show access successful, otherwise it will show denied. LCD dislay will also show clock. if entered password three times denied, then it will move the programmer in continuous loop & will not allow to entered password.

When signal match with the stored password then microcontroller will give its output to stepper motor  circuit through port3. it will give supply to stepper motor & rx pulses from microcontroller .

Then dooor will open.

Microcontrollers:

Look around. Notice the smart “intelligent” systems? Be it the T.V, washing machines, video games, telephones, automobiles, aero planes, power systems, or any application having a LED or a LCD as a user interface, the control is likely to be in the hands of a micro controller!

Measure and control, that’s where the micro controller is at its best.

Micro controllers are here to stay. Going by the current trend, it is obvious that micro controllers will be playing bigger and bigger roles in the different activities of our lives.

These embedded chips are very small, but are designed to replace components  much bigger and bulky In size. They process information very intelligently and efficiently. They sense the environment around them. The signals they gather are tuned into digital data that streams through tributaries of circuit lines at the speed of light. Inside the microprocessor collates and calculators. The software has middling intelligence. Then in a split second, the processed streams are shoved out.

 What is the primary difference between a microprocessor and a micro controller?

Unlike the microprocessor, the micro controller can be considered to be a true “Computer on a chip”.

In addition to the various features like the ALU, PC, SP and registers found on a microprocessor, the micro controller also incorporates features like the ROM, RAM, Ports, timers, clock circuits, counters, reset functions etc.

While the microprocessor is more a general-purpose device, used for read, write and calculations on data, the micro controller, in addition to the above functions also controls the environment.
8051 micro controller

The 8051
The 8051 developed and launched in the early 80`s, is one of the most popular micro controller in use today. It has a reasonably large amount of built in ROM and RAM. In addition it has the ability to access external memory.

The generic term `8×51` is used to define the device. The value of x defining the kind of ROM, i.e. x=0, indicates none, x=3, indicates mask ROM, x=7, indicates EPROM and x=9 indicates EEPROM or Flash.

A note on ROM
The early 8051, namely the 8031 was designed without any ROM. This device could run only with external memory connected to it. Subsequent developments lead to the development of the PROM or the programmable ROM. This type had the disadvantage of being highly unreliable.

The next in line, was the EPROM or Erasable Programmable ROM. These devices used ultraviolet light erasable memory cells. Thus a program could be loaded, tested and erased using ultra violet rays. A new program could then be loaded again.

An improved EPROM was the EEPROM or the electrically erasable PROM. This does not require ultra violet rays, and memory can be cleared using circuits within the chip itself.

Finally there is the FLASH, which is an improvement over the EEPROM. While the terms EEPROM and flash are sometimes used interchangeably, the difference lies in the fact that flash erases the complete memory at one stroke, and not act on the individual cells. This results in reducing the time for erasure.
Different microcontrollers in market.

 

• PIC                  One of the famous microcontrollers used in the industries. It is based on RISC Architecture which makes the microcontroller process faster than other microcontroller.

• INTEL             These are the first to manufacture microcontrollers. These are not as sophisticated other microcontrollers but still the easiest one to learn.

• Atmel                       Atmel’s AVR microcontrollers are one of the most powerful in the embedded industry. This is the only microcontroller having 1kb of ram even the entry stage. But it is unfortunate that in India we are unable to find this kind of microcontroller.

Intel 8051

  Intel 8051 is CISC architecture which is easy to program in assembly language and also has a good support for High level languages.

The memory of the microcontroller can be extended up to 64k.

This microcontroller is one of the easiest microcontrollers to learn.

The 8051 microcontroller is in the field for more than 20 years. There are lots of books and study materials are readily available for 8051.

Derivatives

The best thing done by Intel is to give the designs of the 8051 microcontroller to everyone. So it is not the fact that Intel is the only manufacture for the 8051 there more than 20 manufactures, with each of minimum 20 models. Literally there are hundreds of models of  8051 microcontroller available in market to choose.  Some of the major manufactures of 8051 are

Ø      Atmel

Ø      Philips

Philips

The Philips‘s 8051 derivatives has more number of features than in any microcontroller. The costs of the Philips microcontrollers are higher than the Atmel’s which makes us to choose Atmel more often than Philips

Dallas

Dallas has made many revolutions in the semiconductor market. Dallas’s 8051 derivative is the fastest one in the market. It works 3 times as fast as a 8051 can process. But we are unable to get more in India.

 Atmel

These people were the one to master the flash devices. They are the cheapest microcontroller available in the market. Atmel’s even introduced a 20pin variant of 8051 named 2051. The Atmel’s 8051 derivatives can be got in India less than 70 rupees. There are lots of cheap programmers available in India for Atmel. So it is always good for students to stick with 8051 when you learn a new microcontroller.

Features :-

LCD display- entered password show on LCD

Programmable- flexible- programming can be change , so this project is flexible

Component easily available

Low cost

General use for security system

Applications:

1.    Security System of offices,lockers,rooms

2.    For cranes – we can make cranes with same logic

3.    For lift control- with change in programming we can change in to lift control circuit

Component List:-

Microcontroller 89C051

LCD display 16*2 matrix

Keys matrix

Stepper Motor

Wood or ply

Crystal 3.58Mhz

Resistance 220 ohm

Capacitor 0.01 micro farad

Keyboard general or push to on Button

DIP switches

Connecting wires

Microcontroller programming kit

12v supply

copper clad board

Ferric chloride

Marker

Computer