mini project documentation format

8/2/2019 Mini Project Documentation Format

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PASSWORD SECURED APPLIANCES CONTROL

SYSTEM USING MICROCONTROLLER

A MINI PROJECT REPORT

Submitted in partial fulfillment of the requirements for theAward of the Degree

Of

BACHELOR OF TECHNOLOGY

in

ELECTRONICS AND COMMUNICATION ENGINEERING

By

Mr. B. Dinesh Reddy (07C31A0425)

Mr. Aditya Rao Devaraj (07C31A0408)

Mr. Abhinay Karthik (07C31A0405)

Mr. Praveen Kumar (07C31A0464)

Mr. A. S. Ramesh (07C31A0402)

Under the Guidance of

Mr. P. Kiran KumarAssoc.Prof.

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING

BALAJI INSTITUTE OF TECHNOLOGY AND SCIENCE(Affiliated to JNTU, Hyderabad)

NARSAMPET, WARANGAL506 331201011


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BALAJI INSTITUTE OF TECHNOLOGY AND SCIENCE

NARSAMPET, WARANGAL506 331

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING

CERT I F I CA TE This is to certify that this Project Work entitled PASSWORD SECURED

APPLIANCES CONTROL SYSTEM USING MICROCONTROLLER is a

bonafide work carried out by Mr. B. Dinesh Reddy (07C31A0425), Mr. Aditya Rao

Devaraj (07C31A0408), Mr. Abhinay Karthik (07C31A0405), Mr.Praveen

Kumar (07C31A0464), Mr.A.S.Ramesh (07C31A0402), in partial fulfillment of the

requirements for the award of the degree of Bachelor of Technology from JNTU,

Hyderabad during the period 2010-11 under our guidance and supervision.

Internal Guide Head of the Dept. Principal

Mr. P. Kiran Kumar Prof. S. Umamaheshwar Prof. V. Vikram ReddyAssoc. Prof. Professor & Head Principal,Dept. of ECE Dept. of ECE BITS, NarsampetBITS, Narsampet BITS, Narsampet

EXTERNAL EXAMINER


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DECLARATION

We, Mr. B. Dinesh Reddy (07C31A0425), Mr. Aditya Rao Devaraj

(07C31A0408), Mr. Abhinay Karthik(07C31A0405), Mr. Praveen Kumar

(07C31A0464), Mr. A. S. Ramesh (07C31A0402), here by declare that the project

entitled PASSWORD SECURED APPLIANCES CONTROL SYSTEM USING

MICROCONTROLLER, submitted in the partial fulfillment of the requirements

for the award of Bachelor of Technology in Electronics and Communication

Engineering, to Balaji Institute of Technology & Science, Narsampet, affiliated to

JNTU, Hyderabad is a authentic work and has not been submitted to any other

university or institution for award of the degree.





Mr. A.S. Ramesh (07C31A0402)


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ACKNOWLEDGEMENTS

It is a great pleasure to express our deepest sense of gratitude and indebtedness,

to our Internal guide Mr. P. Kiran Kumar, Assoc. Prof., Dept. of ECE, BITS College

Narsampet, for having been a source of constant inspiration, precious guidance and

generous assistance during the project work. We deem it as a privilege to have worked

under his able guidance. Without his close monitoring and valuable suggestions this

work wouldnt have taken this shape. We feel that this help is un-substitutable and

unforgettable.

We wish to express our sincere thanks to Prof. V. Vikram Reddy, Principal,

BITS, Narsampet for providing the college facilities for the completion of the project.

We are profoundly thankful to Prof. S. Umamaheshwar, Prof., & Head, Dept.

of ECE, for his cooperation and encouragement.

We are greatly thankful to our Project coordinators Mr. P. Kiran Kumar,

Assoc. Prof. & Mr. V. Rama Krishna Reddy, Asst. Prof., Dept. of ECE, BITS,Narsampet for their support throughout our project.

We are thankful to the Mr. P. Ram Chandar Rao, Teaching Asst., Dept. of

ECE, BITS, Narsampet for his Technical Support to carryout our project.

Finally, we thank all the faculty members, supporting staff of ECE Dept. and

friends for their kind co-operation and valuable help for completing the project.





Mr. A. S. Ramesh (07C31A0402)


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ABSTRACT

Security is prime concern in our day-to-day life. Everyone wants to be asmuch as secure as to be possible. An access control systems forms a vital link in a securitychain. The Microcontroller based digital lock presented here is an access control system thatallows only authorized persons to access a restricted area. This system is best suitable for

corporate offices, Banks, ATMs and Home security.The system comprises a small electronic unit with a numeric keypad,

which is fixed outside the entry door to control a solenoid-operated lock with the help of arelay to switch on a Computer (or to run stepper motor). When an authorized person enterspredetermined user ID and password via the keypad, the relay turns on (or stepper motor isoperated).

When the code has been incorrectly entered three times in a row, the codelock will switch to block mode. This function thwarts any attempt by hackers to quickly try

a large number of codes in a sequence. If the user forgets his password, the code lock can beaccessed by a unique 10 digit administrator password. The secret code can be changed anytime after entering the current code (Master code).

An LED is provided for acknowledgment of the key impression.Whenever a key is pressed on the numeric key pad, the system acknowledges the impressionby a short sharp glow of the LED.

This project uses regulated 5V, 500mA power supply. 7805 threeterminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier isused to rectify the ac output of secondary of 230/12V step down transformer.


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CONTENTS

Chapter No. Description Page No.

CHAPTER 1 INTRODUCTION 9

CHAPTER 2 BLOCK DIAGRAM 10

2.1 Block Diagram Description 112.1.1 Power Supply 112.1.2 Transformer 112.1.3 Rectifier 112.1.4 Filter 122.1.5 Voltage Regulator 122.1.6 Microcontrollers 12

2.1.6.1. Features Of P89V51RD2 132.1.6.2. Pin Diagram 16

2.1.6.3. Pin Description 17

CHAPTER 3 PROGRAMMING THE FLASH 20

CHAPTER 4 KEY PAD 24

4.1 Interfacing Keypad 24

CHAPTER 5 TRANSISTOR DRIVER CIRCUIT 27

CHAPTER 6 LIQUID CRYSTAL DISPLAY 28

6.1 Interfacing Liquid Crystal Display 29

CHAPTER 7 SOFTWARES USED 34

7.1 Keil u Vision 347.2 Flash Magic 347.3 Working procedure 34

CHAPTER 8 CODE 37


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LIST OF FIGURES

S.No. Fig. No. Description Page No.

1 Fig.1 Block Diagram 10

2 Fig. 2 Power Supply 11

3 Fig.3 Microcontroller Architecture 13

4 Fig.4 Block Diagram Of P89V51RD2 15

5 Fig.5 Pin Diagram 16

6 Fig.6 Telephone Keypad 24

7 Fig.7 Transistor Driver Circuit 27

8 Fig.8 Procedure of 8-bit Initialisation 33

9 Fig.9 LCD Interfacing with the microcontroller 3310 Fig.10 Schematic Diagram 36


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LIST OF TABLES

S.No. Table No. Description Page No.

1 Table -1 Port 3 Alternate Functions 19

2 Table-2 Flash Programming Modes 22

3 Table-3 LCD Pin Functions 29

4 Table-4 LCD Basic Commands 31


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CHAPTER 1

INTRODUCTION

An embedded system is a combination of software and hardware to p erform a

dedicated task.

Some of the main devices used in embedded products are Microprocessors and

Microcontrollers.

Microprocessors are commonly referred to as general purpose processors as they

simply accept the inputs, process it and give the output.

In contrast, a Microcontroller not only accepts the data as inputs but also manipulates

it, interfaces the data with various devices, controls the data and thus finally gives the result.

The Project Password securedAppliances Control System is an excellent project

that provides security in every way. This project is very useful in places where security is

must.


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CHAPTER 2

BLOCK DIAGRAM

Fig.1 Block Diagram


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2.1. BLOCK DIAGRAM DESCRIPTION

2.1.1. POWER SUPPLY

The input to the circuit is applied from the regulated power supply. The a.c. input i.e.,

230V from the mains supply is step down by the transformer to 12V and is fed to a rectifier.

The output obtained from the rectifier is a pulsating d.c voltage. So in order to get a pure d.c

voltage, the output voltage from the rectifier is fed to a filter to remove any a.c components

present even after rectification. Now, this voltage is given to a voltage regulator to obtain a

pure constant dc voltage.

Fig. 2 Power Supply

2.1.2. TRANSFORMER

Usually, DC voltages are required to operate various electronic equipment and these

voltages are 5V, 9V or 12V. But these voltages cannot be obtained directly. Thus the a.c

input available at the mains supply i.e., 230V is to be brought down to the required voltage

level. This is done by a transformer. Thus, a step down transformer is employed to decrease

the voltage to a required level.

2.1.3. RECTIFIER

The output from the transformer is fed to the rectifier. It converts A.C. into pulsating

D.C. The rectifier may be a half wave or a full wave rectifier. In this project, a bridge rectifieris used because of its merits like good stability and full wave rectification.

RegulatorFilterBridge

Rectifier

Step down

transformer

230V AC

50Hz D.COutput


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2.1.4. FILTER

Capacitive filter is used in this project. It removes the ripples from the output of

rectifier and smoothens the D.C. Output received from this filter is constant until the mains

voltage and load is maintained constant. However, if either of the two is varied, D.C. voltage

received at this point changes. Therefore a regulator is applied at the output stage.

2.1.5. VOLTAGE REGULATOR

As the name itself implies, it regulates the input applied to it. A voltage regulator is an

electrical regulator designed to automatically maintain a constant voltage level. In this

project, power supply of 5V and 12V are required. In order to obtain these voltage levels,7805 and 7812 voltage regulators are to be used. The first number 78 represents positive

supply and the numbers 05, 12 represent the required output voltage levels.

2.1.6. MICROCONTROLLERS

Microprocessors and microcontrollers are widely used in embedded systems products.

Microcontroller is a programmable device. A microcontroller has a CPU in addition to a

fixed amount of RAM, ROM, I/O ports and a timer embedded all on a single chip. The fixed

amount of on-chip ROM, RAM and number of I/O ports in microcontrollers makes them

ideal for many applications in which cost and space are critical.

The Intel 8051 is a Harvard architecture, single chip microcontroller (C) which was

developed by Intel in 1980 for use in embedded systems. It was popular in the 1980s and

early 1990s, but today it has largely been superseded by a vast range of enhanced devices

with 8051-compatible processor cores that are manufactured by more than 20 independent

manufacturers including Philips, Atmel, Infineon Technologies and Maxim Integrated

Products.

8051 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at a

time. Data larger than 8 bits has to be broken into 8-bit pieces to be processed by the CPU.

8051 is available in different memory types such as EEPROM, UV-EPROM, Flash and NV-

RAM.


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The present project is implemented on Keil Uvision. In order to program the device,

Flash Magic tool has been used to burn (dump) the program onto the Microcontroller.

Fig.3 Microcontroller Architecture

The features, pin description of the microcontroller and the software tools used are discussed

in the following sections.

2.1.6.1. FEATURES OF P89V51RD2

GENERAL DESCRIPTION

The P89V51RD2 is an 80C51 microcontroller with 64 kB Flash and 1024 bytes of

data RAM.A key feature of the P89V51RD2 is its X2 mode option. The design engineer can

choose to run application with the conventional 80C51 clock rate (12 clocks per machine

cycle) or select the X2 mode (6 clocks per machine cycle) to achieve twice throughput at the

same clock frequency by half.


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The flash program memory supports both parallel programming and in serial In

System Programming (ISP). Parallel programming mode offers gang programming at high

speed, reducing programming costs and time to market. ISP allows a device to be

reprogrammed in the end product under software control. The capability to field / update the

application firmware makes a wide range of application possible.

The P89V51RD2 is also In Application Programmable (IAP), allowing the flash

program memory to be reconfigured even while the application is running.

FEATURES

80C51Central Processing Unit. 5V Operating voltage from 0 to 40MHz. 64kB of on chip Flash Program memory with ISP (In System Programming) and IAP

(In Application Programming).

Supports 12-clock (default) or 6-clock mode selection via software or ISP. SPI (Serial Peripheral Counter Array) with PWM and Capture/Compare functions. Four 8-bit I/O ports with three high current Port 1 pins (16mA each). Three 16-bit Timers/Counters. Two 16-bit Timer/Counters. Programmable Watch Dog Timer (WDT). Eight interrupt sources with four priority levels. Second DPTR register. Low EMI mode (ALE inhibit). TTL and CMOS compatible logic levels. Brown out detection. Low power modes -1.Power down mode with external interrupt wakeup & 2.Idle

mode.

PDIP40, PLCC44 and TQFP44 packages.


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\

Fig.4 Block Diagram Of P89V51RD2


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2.1.6.2. PINDIAGRAM

Fig.5 Pin Diagram


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2.1.6.3. PIN DESCRIPTION

Vcc-Pin 40 provides supply voltage to the chip. The voltage source is +5V.

GND-Pin 20 is the ground.

XTAL1 and XTAL2

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier

that can be configured for use as an on-chip oscillator, as shown in Figure 11. Either a quartz

crystal or ceramic resonator may be used. To drive the device from an external clock source,

XTAL2 should be left unconnected while XTAL1 is driven, as shown in the below figure.

There are no requirements on the duty cycle of the external clock signal, since the input to the

internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum

voltage high and low time specifications must be observed.

Fig: Oscillator Connections

C1, C2 = 30 pF 10 pF for Crystals

= 40 pF 10 pF for Ceramic Resonators

Fig: External Clock Drive Configuration


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RESET-Pin9 is the reset pin. It is an input and is active high. Upon applying a high pulse to

this pin, the microcontroller will reset and terminate all the activities. This is often referred to

as a power-on reset.

EA (External access)-Pin 31 is EA. It is an active low signal. It is an input pin and must be

connected to either Vcc or GND but it cannot be left unconnected. The 8051 family members

all come with on-chip ROM to store programs. In such cases, the EA pin is connected to Vcc.

If the code is stored on an external ROM, the EA pin must be connected to GND to indicate

that the code is stored externally.

PSEN (Program store enable)-This is an output pin.

ALE (Address latch enable)-This is an output pin and is active high.

Ports 0, 1, 2 and 3-The four ports P0, P1, P2 and P3 each use 8 pins, making them 8-bit

ports. All the ports upon RESET are configured as input, since P0-P3 have value FFH on

them.

Port 0(P0)-Port 0 is also designated as AD0-AD7, allowing it to be used for both address and

data. ALE indicates if P0 has address or data. When ALE=0, it provides data D0-D7, but

when ALE=1, it has address A0-A7. Therefore, ALE is used for demultiplexing address and

data with the help of an internal latch.

When there is no external memory connection, the pins of P0 must be connected to a

10K-ohm pull-up resistor. This is due to the fact that P0 is an open drain. With external pull-

up resistors connected to P0, it can be used as a simple I/O, just like P1 and P2. But the ports

P1, P2 and P3 do not need any pull-up resistors since they already have pull-up resistors

internally. Upon reset, ports P1, P2 and P3 are configured as input ports.

Port 1 and Port 2-With no external memory connection, both P1 and P2 are used as simple

I/O. With external memory connections, port 2 must be used along with P0 to provide the 16-

bit address for the external memory. Port 2 is designated as A8-A15 indicating its dual

function. While P0 provides the lower 8 bits via A0-A7, it is the job of P2 to provide bits A8-

A15 of the address.


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Port 3-Port 3 occupies a total of 8 pins, pins 10 through 17. It can be used as input or output.

P3 does not need any pull-up resistors, the same as port 1 and port 2. Port 3 has an additional

function of providing some extremely important signals such as interrupts.

Table: Port 3 Alternate Functions

Machine cycle for the 8051

The CPU takes a certain number of clock cycles to execute an instruction. In the 8051

family, these clock cycles are referred to as machine cycles. The length of the machine cycle

depends on the frequency of the crystal oscillator. The crystal oscillator, along with on-chip

circuitry, provides the clock source for the 8051 CPU.

The frequency can vary from 4 MHz to 30 MHz, depending upon the chip rating and

manufacturer. But the exact frequency of 11.0592 MHz crystal oscillator is used to make the

8051 based system compatible with the serial port of the IBM PC.

In the original version of 8051, one machine cycle lasts 12 oscillator periods.

Therefore, to calculate the machine cycle for the 8051, the calculation is made as 1/12 of the

crystal frequency and its inverse is taken.

The assembly language program is written and this program has to be dumped into the

microcontroller for the hardware kit to function according to the software. The program

dumped in the microcontroller is stored in the Flash memory in the microcontroller. Before

that, this Flash memory has to be programmed and is discussed in the next section.


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CHAPTER 3

PROGRAMMING THE FLASH

PROGRAMMING THE FLASH

The P89V51RD2 is normally shipped with the on-chip Flash memory array in the

erased state (that is, contents = FFH) and ready to be programmed. The programming

interface accepts either a high-voltage (12-volt) or a low-voltage (VCC) program enable

signal. The low-voltage programming mode provides a convenient way to program the

P89V51RD2 inside the users system, while the high-voltage programming mode is

compatible with conventional third party Flash or EPROM programmers. The P89V51RD2 is

shipped with either the high-voltage or low-voltage programming mode enabled. The

respective top-side marking and device signature codes are listed in the following table.

The P89V51RD2 code memory array is programmed byte-byte in either programming

mode.

To program any nonblank byte in the on-chip Flash Memory, the entire memory must

be erased using the Chip Erase Mode.

PROGRAMMING ALGORITHM

Before programming the P89V51RD2, the address, data and control signals should be

set up according to the Flash programming mode table. To program the P89V51RD2, the

following steps should be considered:

1. Input the desired memory location on the address lines.

2. Input the appropriate data byte on the data lines.

3. Activate the correct combination of control signals.

4. Raise EA/VPP to 12V for the high-voltage programming mode.

5. Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-

write cycle is self-timed and typically takes no more than 1.5 ms.

Repeat steps 1 through 5, changing the address and data for the entire array or until the end of

the object file is reached.


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DATA POLLING

The P89V51RD2 features Data Polling to indicate the end of a write cycle. During a

write cycle, an attempted read of the last byte written will result in the complement of the

written datum on PO.7. Once the write cycle has been completed, true data are valid on all

outputs, and the next cycle may begin. Data Polling may begin any time after a write cycle

has been initiated.

READY/BUSY

The progress of byte programming can also be monitored by the RDY/BSY output

signal. P3.4 is pulled low after ALE goes high during programming to indicate BUSY. P3.4

is pulled high again when programming is done to indicate READY.

CHIP ERASE

The entire Flash array is erased electrically by using the proper combination of

control signals and by holding ALE/PROG low for 10 ms. The code array is written with all

1s. The chip erase operation must be executed before the code memory can be re

programmed.

READING THE SIGNATURE BYTESThe signature bytes are read by the same procedure as a normal verification of

locations 030H, 031H, and 032H, except that P3.6 and P3.7 must be pulled to a logic low.

The values returned are as follows.

(030H) = 1EH indicates manufactured by Atmel

(031H) = 51H indicates 89C51

(032H) = FFH indicates 12V programming(032H) = 05H indicates 5V programming

PROGRAMMING INTERFACE

Every code byte in the Flash array can be written and the entire array can be erased by

using the appropriate combination of control signals. The write operation cycle is self timed

and once initiated, will automatically time itself to completion. All major programming

vendors offer worldwide support for the Atmel microcontroller series.


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Fig: Flash Programming Modes

EEPROM

In the design of all microprocessors-based systems, semiconductor memories are used

as primary storage for code and data. Semiconductor memories are connected directly to the

CPU and they are the memory that the CPU first asks for information (code and data). For

this reason, semiconductor memories are sometimes referred to as primary memory.

IMPORTANT TERMINOLOGY COMMON TO ALL SEMICONDUCTOR

MEMORIES

MEMORY CAPACITY

The number of bits that a semiconductor memory chip can store is called chip

capacity. It can be in units of Kilobits, Megabits and so on. This must be distinguished from

the storage capacity of computer system. While the memory capacity of a memory IC chip is

always given in bits, the memory capacity of a computer system is given in bytes.

MEMORY ORGANIZATION


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Memory chips are organized into a number of locations within the IC. Each location

can hold 1 bit, 4 bits, 8 bits or even 16 bits, depending on how it is designed internally. The

number of bits that each location within the memory chip can hold is always equal to the

number of data pins on the chip. i.e., the total number of bits that a memory chip can store is

equal to the number of locations times the number of data bits per location.

SPEED

One of the most important characteristics of a memory chip is the speed at which its

data can be accessed. The speed of the memory chip is commonly referred to as its access

time. The access time of memory chip varies from a few nanoseconds to hundreds of

nanoseconds, depending on the IC technology used in the design and fabrication process.

The different types of memories are RAM, ROM, EPROM and EEPROM.

RAM and ROM are inbuilt in the microprocessor.

This project requires the data such as the user identification number and password to

be stored permanently. Thus this data has to be stored in such a location where it cannot be

erased when power fails and also the data should be allowed to make changes in it without

the system interface i.e., there should be a provision in such a way that the data should be

accessed (or modified) while it is in system board but not external erasure and programming.

The flash memory inbuilt in the microcontroller can erase the entire contents in less than a

second and the erasure method is electrical. But the major drawback of Flash memory is that

when flash memorys contents are erased, the entire device will be erased but not a desired

section or byte.

For this purpose, we prefer EEPROM in our project.

EEPROM (ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY

MEMORY)

EEPROM has several advantages over other memory devices, such as the fact that its

method of erasure is electrical and therefore instant. In addition, in EEPROM one can select

which byte to be erased, in contrast to flash , in which the entire contents of ROM are erased.

The main advantage of EEPROM is that one can program and erase its contents while it is in

system board. It does not require physical removal of the memory chip from its socket. In

general, the cost per bit for EEPROM is much higher when compared to other devices.


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CHAPTER 4

KEYPAD

KEYPAD

Keypads and LCDs are the most widely used input/output devices of the 8051 and a

basic understanding of them is essential. The keypads are mainly three types:

1. 4*3 keypad2. 4*4 keypad3. 4*8 keypad.

The keypad used in this project is 4*3 keypad.

Fig.6 Telephone Keypad

INTERFACING THE KEYPAD TO 8051

At the lowest level, keyboards are organized in a matrix of rows and columns. The

CPU accesses both rows and columns through ports. Therefore, with two 8-bit ports, an 8*8

matrix of keys can be connected to a microprocessor. When a key is pressed, a row and a

column make a contact, otherwise there is no connection between rows and columns. A

single microcontroller (consisting of a microprocessor, RAM, EPROM and several ports allon a single chip) takes care of hardware and software interfacing of the keypad. In such


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systems, it is the function of programs stored in EPROM of the microcontroller to scan the

keys continuously, identify which one has been activated and present it to the motherboard.

Fig: 4*3 Matrix Keypad Connections to Ports

SCANNING AND IDENTIFYING KEY

The rows are connected to an output port and the columns are connected to an input

port. If no key has been pressed, reading the input port will yield 1s for all columns since they

are all connected to high (Vcc). If all the rows are grounded and a key is pressed, one of the

columns will have 0 since the key pressed provides the path to ground. It is the function of

the microcontroller to scan the keypad continuously to detect and identify the key pressed.

GROUNDING ROWS AND READING THE COLUMNS

To detect a pressed key, the microcontroller grounds all rows by providing 0 (zero) to

the output latch, then it reads the columns. If the data read from the columns is D2-D0 =111,

no key has been pressed and the process continues until a key press is detected. However, if

one of the column bits has a zero, this means that a key press has occurred i.e., for example, if


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D2-D0=110, this means that a key in the D0 column has been pressed. After a key press is

detected, the microcontroller will go through a process of identifying the key. Starting with

the top row, the microcontroller grounds it by providing a low to row D0 only and then it

reads the columns. If the data read is all 1s, no key in that row is activated and the process is

moved to the next row. It grounds the next row, reads the columns and checks for any zero.

This process continues until the row is identified. After identification of the row in which the

key has been pressed, the next task is to find out which column the pressed key belongs to.

Now this will be easy since the microcontroller knows at any time which row and column are

being accessed.


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CHAPTER 5

TRANSISTOR DRIVER CIRCUIT

TRANSISTOR DRIVER CIRCUIT

Digital systems and microcontroller pins lack sufficient current to drive the circuits

like LED circuits and relay circuits. While these circuits need around 10milli amps to be

energized, the microcontrollers pin can provide a maximum of 1-2milli amps current. For

this reason, a driver such as a power transistor is placed in between the microcontroller and

the LED.

Fig.7 Transistor Driver Circuit

OPERATION OF THE CIRCUIT

The input to the base of the transistor is applied from the microcontroller port pin

P1.0. The transistor will be switched on when the base to emitter voltage is greater than 0.7V

(cut-in voltage). Thus when the voltage applied to the pin P1.0 is high i.e., P1.0=1 (>0.7V),

the transistor will be switched on and thus the LED will be activated and produces a glow.

When the voltage at the pin P1.0 is low i.e., P1.0=0 (


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CHAPTER 6

LIQUID CRYASTAL DISPLAY

LIQUID CRYSTAL DISPLAY

LCD stands for Liquid Crystal Display. LCD is finding wide spread use replacing

LEDs (seven segment LEDs or other multi segment LEDs) because of the following reasons:

1. The declining prices of LCDs.2. The ability to display numbers, characters and graphics. This is in contrast to LEDs,

which are limited to numbers and a few characters.

3. Incorporation of a refreshing controller into the LCD, thereby relieving the CPU ofthe task of refreshing the LCD. In contrast, the LED must be refreshed by the CPU to

keep displaying the data.

4. Ease of programming for characters and graphics.These components are specialized for being used with the microcontrollers, which

means that they cannot be activated by standard IC circuits. They are used for writing

different messages on a miniature LCD.

A model described here is for its low price and great possibilities most frequently

used in practice. It is based on the HD44780 microcontroller (Hitachi) and can display

messages in two lines with 16 characters each . It displays all the alphabets, Greek letters,

punctuation marks, mathematical symbols etc. In addition, it is possible to display symbols

that user makes up on its own. Automatic shifting message on display (shift left and right),

appearance of the pointer, backlight etc. are considered as useful characteristics.


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PIN FUNCTIONS

There are pins along one side of the small printed board used for connection to the

microcontroller. There are total of 14 pins marked with numbers (16 in case the background

light is built in). Their function is described in the table below:

FunctionPin

NumberName

Logic

StateDescription

Ground 1 Vss - 0V

Power supply 2 Vdd - +5V

Contrast 3 Vee - 0Vdd

Control ofoperating

4 RS0

1

D0D7 are interpreted as

commands

D0D7 are interpreted as data

5 R/W

0

1

Write data (from controller to

LCD)

Read data (from LCD to

controller)

6 E

0

1

From 1 to

0

Access to LCD disabled

Normal operating

Data/commands are transferred to

LCD

Data / commands

7 D0 0/1 Bit 0 LSB

8 D1 0/1 Bit 1

9 D2 0/1 Bit 2

10 D3 0/1 Bit 3

11 D4 0/1 Bit 4

12 D5 0/1 Bit 5

13 D6 0/1 Bit 6

14 D7 0/1 Bit 7 MSB


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LCD SCREEN

LCD screen consists of two lines with 16 characters each. Each character consists of

5x7 dot matrix. Contrast on display depends on the power supply voltage and whether

messages are displayed in one or two lines. For that reason, variable voltage 0-Vdd is applied

on pin marked as Vee. Trimmer potentiometer is usually used for that purpose. Some

versions of displays have built in backlight (blue or green diodes). When used during

operating, a resistor for current limitation should be used (like with any LE diode).

LCD BASIC COMMANDS

All data transferred to LCD through outputs D0-D7 will be interpreted as commands

or as data, which depends on logic state on pin RS:

RS = 1 - Bits D0 - D7 are addresses of characters that should be displayed. Built in processor

addresses built in map of characters and displays corresponding symbols. Displaying

position is determined by DDRAM address. This address is either previously defined or the

address of previously transferred character is automatically incremented.

RS = 0 - Bits D0 - D7 are commands which determine display mode. List of commands

which LCD recognizes are given in the table below:


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I/D

1 =

Incr

eme

nt

(by

1)

R/L

1 =

Shif

t

right

0 = Decrement (by 1) 0 = Shift left

S 1 = Display shift on DL 1 = 8-bit interface

0 = Display shift off 0 = 4-bit interface

D 1 = Display on N 1 = Display in two lines

0 = Display off 0 = Display in one line

U 1 = Cursor on F 1 = Character format 5x10 dots

0 = Cursor off 0 = Character format 5x7 dots

B 1 = Cursor blink on D/C 1 = Display shift

0 = Cursor blink off 0 = Cursor shift

Command RSRWD7D6D5D4D3 D2 D1 D0Execution

Time

Clear display 0 0 0 0 0 0 0 0 0 1 1.64mS

Cursor home 0 0 0 0 0 0 0 0 1 x 1.64mS

Entry mode set 0 0 0 0 0 0 0 1 I/D S 40uS

Display on/off control 0 0 0 0 0 0 1 D U B 40uS

Cursor/Display Shift 0 0 0 0 0 1 D/C R/L x x 40uS

Function set 0 0 0 0 1 DL N F x x 40uS

Set CGRAM address 0 0 0 1 CGRAM address 40uS

Set DDRAM address 0 0 1 DDRAM address 40uS

Read BUSY flag (BF) 0 1 BF DDRAM address -

Write to CGRAM or

DDRAM1 0 D7 D6 D5 D4 D3 D2 D1 D0 40uS

Read from CGRAM or

DDRAM1 1 D7 D6 D5 D4 D3 D2 D1 D0 40uS


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LCD INITIALISATION

Once the power supply is turned on, LCD is automatically cleared. This process lasts

for approximately 15mS. After that, display is ready to operate. The mode of operating is set

by default. This means that:

1. Display is cleared

2. Mode

DL = 1 Communication through 8-bit interface

N = 0 Messages are displayed in one line

F = 0 Character font 5 x 8 dots

3. Display/Cursor on/off

D = 0 Display offU = 0 Cursor off

B = 0 Cursor blink off

4. Character entry

ID = 1 Addresses on display are automatically incremented by 1.

S = 0 Display shift off

Automatic reset is mainly performed without any problems. Mainly but not always! If

for any reason power supply voltage does not reach full value in the course of 10mS, display

will start perform completely unpredictably. If voltage supply unit can not meet this condition

or if it is needed to provide completely safe operating, the process of initialization by which a

new reset enabling display to operate normally must be applied.

Algorithm according to the initialization is being performed depends on whether

connection to the microcontroller is through 4- or 8-bit interface. All left over to be done after

that is to give basic commands and of course- to display messages.


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Fig: Procedure on 8-bit initialization.

LCD INTERFACING WITH THE MICROCONTROLLER

P2.0P2.1P2.2

P89V51RD2

P1.0P1.1P1.2P1.3

P1.4P1.5P1.6P1.7

4 (RS) 15 (R/W) 26(EN) 3

LCD

D0D1D2D3

D4D5 15D6 16D7


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CHAPTER 7

SOFTWARES USED

KEIL COMPILER

Keil compiler is a software used where the machine language code is written and

compiled. After compilation, the machine source code is converted into hex code which is to

be dumped into the microcontroller for further processing. Keil compiler also supports C

language code.

FLASH MAGIC

Flash-Magic is the Software which accepts any file like hex, assembly language, C,

C++, JAVA class files. Once the machine code is converted into hex code, that hex code has

to be dumped into the microcontroller and this is done by the Flash-Magic. Flash-Magic is a

programmer which itself contains a microcontroller in it other than the one which is to be

programmed. This microcontroller has a program in it written in such a way that it accepts

the hex file from the keil compiler and dumps this hex file into the microcontroller which is

to be programmed. As the Flash-Magic programmer kit requires power supply to be operated,this power supply is given from the power supply circuit designed above. It should be noted

that this programmer kit contains a power supply section in the board itself but in order to

switch on that power supply, a source is required. Thus this is accomplished from the power

supply board with an output of 12volts.

WORKING PROCEDURE

The Project Password based Computer control system using P89V51RD2

Microcontroller is an exclusive project that provides security at Corporate Offices, Banks,

ATM centers, offices and homes.

Security is of primary concern and in this busy, competitive world, human cannot find

ways to provide security to his confidential belongings manually. Instead, he finds an

alternative which can provide a full fledged security as well as automized. This project has

been developed on this motto.


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In this project every user, a part of an organization, is given an unique user ID and

password. The passwords of all the users of that particular organization will be stored in

EEPROM present in the system board because the data in EEPROM can be changed any

number of times without the physical removal of the memory chip from its socket.

This system will be fixed at the main door of the restricted area. Whenever the user tries to

enter into the organization, this system asks the user to enter his user id. This message Enter

USER ID will be displayed on the LCD. Then the user has to enter his identification number

then, The microcontroller accepts this data and compares this user id which is already stores

in the EEPROM. If the user id is not matched with any of the stored user ids, the

microcontroller will not proceed for further details but displays a message Invalid USER

ID. If this user id is matched with any one of the already stored user ids, then the system

asks the user to enter his password. After he enters his password, the microcontroller onceagain compares the entered password with the already passwords in the EEPROM. If this

password matches with any one of the passwords stored, the microcontroller supllies the

power to the computer by enabling the relay for the person to enter into the restricted area

and the message PROCESSING will be displayed on the LCD display.

But if the entered password does not match with the already stored passwords, the

message Password failed. Enter ID will be displayed on the LCD and the computer does

not on.

If the password is entered wrongly for 3 times continuously, then the total system will

be blocked. The system can come to normal condition only after pressing the RESET switch.

Initially the system is given with default passwords as shown below.

User ID Password

101 555

102 556

103 557

104 558

If the user forgot his password then he should consult administrator. Then the

administrator enters a 10 digit code which is admin PSWD. Then the forgotte n password is

displayed on LCD. Default password for administrator is 1234567890. # key should be

entered after completion of entering ID or password. This key acts like a ENTER key.


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Fig: SCHEMATIC DIAGRAM


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CHAPTER 8

CODE

FAILCOUNT DATA 22H

KEYCOUNT DATA 25H ;TO STORE THE NO. KEYS ENTERD FOR EACH

TIME

TEMP DATA 26H ;TEMP VARIABLE

PWDFIND DATA 27H ;TO FIND WHICH PASSWORD SHOULD BE

COMPARED

PCOUNT1 DATA 28H ;TO STORE THE NO.OF DIGITS OF

PASSWORD1

PCOUNT2 DATA 29H ;TO STORE THE NO.OF DIGITS OF

PASSWORD2

PCOUNT3 DATA 2AH ;TO STORE THE NO.OF DIGITS OF

PASSWORD3

PCOUNT4 DATA 2BH ;TO STORE THE NO.OF DIGITS OF

PASSWORD4

ORG 00H

MOV P3,#00000111B ;MAKE P3.0-P3.2 AS INPUT PINS FOR

COLUMNS

MOV R1,#50H ;SCANNED KEY IS STORED IN THIS

LOCATION

;MOV R0,#0

CLR P2.7 ; LED OFF

MOV FAILCOUNT,#0

;LCD INTIALIZATION

MOV DPTR,#COMM

XX: CLR A

MOVC A,@A+DPTR

JZ START1

ACALL COMMAND

ACALL DELAYINC DPTR


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SJMP XX

START1: MOV DPTR,#MSGA ;DISPLAY "BITS"

ACALL DISPLAY1

ACALL DELAY

ACALL DELAY

ACALL DELAY

MOV A,#0C0H

ACALL COMMAND

ACALL DELAY

MOV DPTR,#MSGB

ACALL DISPLAY1

ACALL DELAYACALL DELAY

ACALL DELAY

MOV DPTR,#MSG ;DISPLAY "SECURITY SYSTEM"

ACALL DISPLAY

ACALL DELAY

START2: CLR P2.7

MOV DPTR,#MSG1 ;ASKING FOR ID

ACALL DISPLAY

ACALL DELAY

ACALL KEYSCAN ;ENTER THE ID

ACALL DELAY

ACALL COMPARISON ;ID COMPARISION

ACALL DELAY

SJMP START2

/*@@@@@@@ KEYSCAN SUBROUTINE @@@@@@@@@@@@@@@*/

KEYSCAN: MOV R1,#50H ;SCANNED KEY IS STORED IN THIS

LOCATION

MOV A,#0C3H

;ENTERD KEYS ARE DISPLAYED FROM 4TH LOCATION OF 2ND LINE

LCALL COMMAND

LCALL DELAY

MOV KEYCOUNT,#0


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NEXTKEY: MOV P0,#0F0H ;GROUND ALL ROWS INTIALLY

MOV A,P3 ;READ ALL COLMNS;ENSURE ALL KEYS

OPEN

ANL A, #00000111B

CJNE A,#00000111B,NEXTKEY

K2: ACALL DELAY

MOV A,P3 ;READ ALL COLMNS;ENSURE ALL KEYS

OPEN

ANL A, #00000111B

CJNE A,#00000111B,OVER

SJMP K2

OVER: ACALL DELAYMOV A,P3 ;READ ALL COLMNS

ANL A, #00000111B

CJNE A,#00000111B,OVER1

SJMP K2

OVER1: MOV P0,#00001110B ;GROUND ROW 0

MOV A,P3 ;READ ALL COLMNS

ANL A, #00000111B

CJNE A,#00000111B,ROW_0

MOV P0,#00001101B ;GROUND ROW 1


ANL A, #00000111B

CJNE A,#00000111B,ROW_1



ANL A, #00000111B

CJNE A,#00000111B,ROW_2



ANL A, #00000111B

CJNE A,#00000111B,ROW_3

LJMP K2

ROW_0: MOV DPTR,#KCODE0

SJMP FIND


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SJMP FIND


SJMP FIND


FIND: RRC A

JNC MATCH

INC DPTR

SJMP FIND

MATCH: SETB P2.7

ACALL DELAY ;IF KEY IS DETECTED THEN GIVE A BEEP

SOUNDACALL DELAY

CLR P2.7

CLR A

MOVC A,@A+DPTR

MOV @R1,A

CJNE A,#23H,NK ;STOP THE KEYSCANNING WHEN '#' IS

PRESSED

RET

NK: ACALL DATAWRT ;DISPLAY THE

PRESSED KEY

ACALL DELAY

INC KEYCOUNT

INC R1

SJMP NEXTKEY

COMPARISON: MOV A,KEYCOUNT

CJNE A,#3,FFAIL

CHECKID1: MOV A,#'1' ;COMPARE WITH ID1

CJNE A, 50H, CHECKID2

MOV A,#'0'

CJNE A,51H,CHECKID2

MOV A,#'1'

CJNE A,52H,CHECKID2


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SJMP PWDCHECK1 ;IF ID MATCHED GO FOR ITS

PASSWORD


CJNE A,50H,CHECKID3

MOV A,#'0'

CJNE A,51H,CHECKID3

MOV A,#'2'

CJNE A,52H,CHECKID3

SJMP PWDCHECK2

;COMPARE WITH ID3


CJNE A,50H,CHECKID4MOV A,#'0'

CJNE A,51H,CHECKID4

MOV A,#'3'

CJNE A,52H,CHECKID4

SJMP PWDCHECK3

;COMPARE WITH ID4


CJNE A,50H,FFAIL

MOV A,#'0'

CJNE A,51H,FFAIL

MOV A,#'4'

CJNE A,52H,FFAIL

LJMP PWDCHECK4

FFAIL: LJMP FAIL

PWDCHECK1: MOV PWDFIND,#10000001B ;TO SET 8th,1st BIT

THIS LOGIC IS USED TO KNOW WHICH ID'S PASSWORD SHOULD BE COMPARED

MOV DPTR,#MSG2 ;ASK FOR PASSWORD

ACALL DISPLAY

ACALL KEYSCAN ;ENTER PASSWORD

ACALL DELAY

MOV A,KEYCOUNT

CJNE A,#10,PD1 ;IF NO.OF KEYS ENTERD

ARE 10 THEN GO COMPARE WITH ADMINPASSWORD


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LJMP ADMIN_PSWD

PD1: MOV PCOUNT1,KEYCOUNT ;LOAD THE NO.OF DIGITS

OF PASSWORD1 IN PCOUNT1

ACALL NEXT ;CHECK WHETHER USER

WANTS TO CHANGE PASSWORD OR NOT

LJMP START2

PWDCHECK2: MOV PWDFIND,#01000010B ;TO SET 7th AND 2nd BIT

MOV DPTR,#MSG2

ACALL DISPLAY

ACALL KEYSCAN

ACALL DELAY

MOV A,KEYCOUNTCJNE A,#10,PD1

LJMP ADMIN_PSWD

PD11: MOV PCOUNT2,KEYCOUNT

ACALL NEXT

LJMP START2

PWDCHECK3: MOV PWDFIND,#00100100B ;TO SET 6th,3rd BIT

MOV DPTR,#MSG2

ACALL DISPLAY

ACALL KEYSCAN

ACALL DELAY

MOV A,KEYCOUNT

CJNE A,#10,PD111

LJMP ADMIN_PSWD


ACALL NEXT

LJMP START2

PWDCHECK4: MOV PWDFIND,#00011000B ;TO SET 5th,4th BIT

MOV DPTR,#MSG2

ACALL DISPLAY

ACALL KEYSCAN

ACALL DELAY

MOV A,KEYCOUNT

CJNE A,#10,PD1111


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LJMP ADMIN_PSWD


ACALL NEXT

LJMP START2

NEXT: MOV A,KEYCOUNT

CJNE A,#3,INTIALCHECK

MOV A,#'1'

CJNE A,50H,INTIALCHECK



INTIALCHECK: ACALL CHECKPWD

ACALL DELAYLJMP SUCCESS

CHECKPWD: JB PWDFIND.7,PSWD1

JB PWDFIND.6,PSWD2

JB PWDFIND.5,PSWD3

JB PWDFIND.4,PSWD4

LJMP START2

PSWD1: MOV A,PCOUNT1

MOV A,#'5' ;COMPARE WITH ID1

CJNE A,50H,K

MOV A,#'5'

CJNE A,51H,K

MOV A,#'5'

CJNE A,52H,K

LJMP SUCCESS

K: LJMP FAIL



CJNE A,50H,AA

MOV A,#'5'

CJNE A,51H,AA

MOV A,#'6'

CJNE A,52H,AA

LJMP SUCCESS


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AA: LJMP FAIL



CJNE A,50H,KK

MOV A,#'5'

CJNE A,51H,KK

MOV A,#'7'

CJNE A,52H,KK

LJMP SUCCESS

KK: LJMP FAIL


MOV A,#'5' ;COMPARE WITH ID4CJNE A,50H,KKK

MOV A,#'5'

CJNE A,51H,KKK

MOV A,#'8'

CJNE A,52H,KKK

LJMP SUCCESS

KKK: LJMP FAIL

RET

KJ: LJMP FAIL

ADMIN_PSWD: MOV A,#'1' ;COMPARE WITH ID ADMIN_PSWD

CJNE A,50H,KJ

MOV A,#'2'

CJNE A,51H,KJ

MOV A,#'3'

CJNE A,52H,KJ

MOV A,#'4'

CJNE A,53H,KJ

MOV A,#'5'

CJNE A,54H,KJ

MOV A,#'6'

CJNE A,55H,KJ

MOV A,#'7'

CJNE A,56H,KJ


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MOV A,#'8'

CJNE A,57H,KJ

MOV A,#'9'

CJNE A,58H,KJ

MOV A,#'0'

CJNE A,59H,KJ

;IF ADMIN PASSWORD IS MATCHED THEN DISPLAY THE RESPECTIVE USER'S

PASSWORD

MOV DPTR,#MSG5

ACALL DISPLAY

JB PWDFIND.0,DISP_PWD1

JB PWDFIND.1,DISP_PWD2JB PWDFIND.2,DISP_PWD3

JB PWDFIND.3,DISP_PWD4

DISP_PWD1: MOV A,#0C0H

ACALL COMMAND

ACALL DELAY

MOV DPTR,#PWD1 ;IF THE ID & PSWD ARE

MATCHED THEN PC STARTS

ACALL DISPLAY

ACALL L_DELAY

SJMP DO_AGAIN

;DISPLAY PASSWORD2


ACALL COMMAND

ACALL DELAY



ACALL DISPLAY

ACALL L_DELAY

SJMP DO_AGAIN

;DISPLAY PASSWORD3


ACALL COMMAND

ACALL DELAY


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ACALL DISPLAY

ACALL L_DELAY

SJMP DO_AGAIN

;DISPLAY PASSWORD4


ACALL COMMAND

ACALL DELAY



ACALL DISPLAYACALL L_DELAY

DO_AGAIN: LJMP START2

SUCCESS: MOV FAILCOUNT,#0

MOV DPTR,#MSG3

ACALL DISPLAY

ACALL DEVICE

LJMP START2

FAIL: MOV DPTR,#MSG4

ACALL DISPLAY

INC FAILCOUNT

MOV A,#3

CJNE A,FAILCOUNT,TRY1

MOV FAILCOUNT,#0

MOV DPTR,#MSG10

ACALL DISPLAY

SETB P2.7

SJMP $

TRY1: SETB P2.7

ACALL DLAYms

ACALL DLAYms

CLR P2.7

ACALL DELAY

ACALL DELAY


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SETB P2.7

ACALL DLAYms

ACALL DLAYms

CLR P2.7

ACALL DELAY

ACALL DELAY

SETB P2.7

ACALL DLAYms

ACALL DLAYms

LJMP START2

DEVICE : MOV DPTR,#MSG7

ACALL DISPLAYACALL DELAY

DD: SETB P2.7

CLR P2.0

SJMP DD

RET

/* LCD DISPLAY SUBROUTINE */

DISPLAY: MOV A,#01H

ACALL COMMAND

ACALL DELAY

DISPLAY1: CLR A

MOVC A,@A+DPTR

JZ XYZ

ACALL DATAWRT

ACALL DELAY

INC DPTR

SJMP DISPLAY1

XYZ: MOV A,#0C4H

ACALL COMMAND

ACALL DELAY

RET

;SEND COMMANDS TO LCD

COMMAND: MOV P1,A


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CLR P3.3

CLR P3.4

SETB P3.5

ACALL DELAY

CLR P3.5

RET

;SEND DATA TO LCD

DATAWRT: MOV P1,A

SETB P3.3

CLR P3.4

SETB P3.5

ACALL DELAYCLR P3.5

RET

DELAY: MOV R6,#200

HERE1: MOV R7,#100

HERE: DJNZ R7,HERE

DJNZ R6,HERE1

RET

DLAYms: MOV R6,#100

MOV B,#00

MS1: DJNZ B,$

DJNZ B,$

DJNZ R6,MS1

RET

L_DELAY: MOV R7,#0AH

LLL: LCALL DLAYms

DJNZ R7,LLL

RET

COMM: DB 38H,0EH,01H,06H,84H,00H

ID1: DB "101",0

ID2: DB "102",0

ID3: DB "103",0

ID4: DB "104",0


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PWD1: DB "555",0

PWD2: DB "556",0

PWD3: DB "557",0

PWD4: DB "558",0

ADMINPWD: DB "1234567890",0

MSGA: DB "BITS",0

MSGB: DB "ECE-A,IV YEAR...",0

MSG: DB "SECURITY SYSTEM",0

MSG1: DB "ENTER ID",0

MSG2: DB "ENTER PASSWORD",0

MSG3: DB "SUCCESS",0MSG4: DB "FAIL",0

MSG5: DB "YOUR PSWD IS ",0

MSG6: DB "MAX LENTH OVER ",0

MSG7: DB "SYSTEM ON.. ",0

MSG8: DB "SYSTEM OFF.. ",0

MSG9: DB "INVALID PSWD ",0

MSG10: DB " SYSTEM BLOCKED ",0

MSG11: DB " BITS... ",0

KCODE0: DB '1','2','3'

KCODE1: DB '4','5','6'

KCODE2: DB '7','8','9'

KCODE3: DB '*','0','#'

END

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