DOC B.1 Security 2

7/29/2019 DOC B.1 Security 2

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GOKARAJU RANGARAJU INSTITUTE OF

ENGINEERING AND TECHNOLOGY

Hyderabad, Andhra Pradesh.

DEPARTMENT OF ELECTRICAL & ELECTRONICS

ENGINEERING

[1]


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DIGITAL SECURITY CODE LOCK USING

8051 MICROCONTROLLER

By :

ANIL . R (07241A0258)

ANUDEEP REDDY.R (07241A0259)

BHANU CHANDER.V (07241A0262)

SAATWIK.G (07241A0295)

SAI KISHORE .P (07241A0296)

[2]


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CONTENTS

TOPIC PAGE NO.

Abstract 04

1. Introduction 05

2. Block Diagram & Description 10

3. Hardware Design 13

4. Software Design 29

5. Testing and Results 32

6. Source code 34

7. Applications ,Advantages 48

& Disadvantages

8. References 52

[3]


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ABSTRACT :

The microcontroller based digital lock is an access control system that allows only

authorized persons to access any restricted division. The major components include

a keypad, LCD,EEPROM and the micro controller AT89C51 which belongs to the

8051 series of micro controllers . The system is fully controlled by the 8 bit

microcontroller AT89C51 which has a 2Kbytes of ROM for the program memory.

The electronic control assembly allows the system to unlock the device with a

password.A four digit predefined password needs to be specified the user. A 4x3

matrix KEYPAD and a 16x2 LCD have been used here to set the password which

is stored in the EPROM so that we can change it at any time. 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, 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 the digit is displayed on

LCD. If all the four digits match with set password, LCD displays password is

correct and the lock output pin goes high and the led glows. If the security code

is wrong, Wrong Password is sent to be displayed on LCD and the buzzer rings

which is connected to the microcontroller. It has wide applications in the present

world. It is mainly used for door alarms, equipment privacy locks, cell phones,

computers and in many lock systems.

[4]


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Chapter 1: INTRODUCTION

1.1 Objective

1.2 What is Digital security code lock?

1.3 Need for Digital security code lock

[5]

1.4 Introduction


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1.1 Objective :

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. The system is fully controlled by the 8

bit microcontroller AT89C51 which has a 4Kbytes 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. If we entered a wrong password for more than three times then the Alarm is

switched on.

[6]


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1.2

What is Digital security code lock?

'Digital Security' gives individuals the freedom to embrace the

digital lifestyle confidently engage in everyday interactions across all digital devices.

According to Olivier Piou, CEO of global digital security company Gemalto, digital

security hasa key role to play in the digital revolution. Yet fear of fraud, identity theft,

and other concerns are holding people back from making the most of (what the digital

revolution has to offer). They need to feel that the wealth of devices and services

available are both convenient to use and trustworthy."Digital security affects all

aspects of the digital lifestyle, which, among others, comprises computers and the

internet, telecommunications, financial transactions, transportation, healthcare and

secure access.

New approaches offer the best of both worlds by combining network DVR capabilities

with intelligent access control and alarm monitoring panel functionality into a

single IP solution. Systems now combine digital video Monitoring/recording,

access control and intrusion detection functionality in a single panel solution. With

these integrated digital video recording and access control platforms, security officers

can display live and stored video associated with alarm conditions and cardholder

activity

When considering the security measures that are typically installed within homes and

properties, they often are systems that are not effective and not of much use. With the

number of contemptible acts like robberies, ransacking and vandalism, the absence of

competent security solutions is an open invitation to trouble. Digital cameras are

extremely useful devices that ensure the safety of your property when you are away at

work on or vacation. With technological advancements you can now implement

strong measures to keep trouble makers away

[7]


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[8]

1.3Need for Digital security code lock

We have seen the security personnel checking the employees identification cards

at the entrances to avoid illegal entry. The employees sign a register at the entrance before

getting in. This is still being practiced in most of the companies.

However, the disadvantages are that, when there is a necessity of providing

control at many locations inside the company, a person at each point will not be an

economical way of implementing it.

Then came were the punch cards. Employees possess cards, which are punched

when they enter into the building. But it had disadvantages. Workers started to practice

buddy punching, for their co-workers.

Concerns about buddy punching-the practice where employees fraudulently clock

their co-workers in or out to give them credit for time that wasn't actually worked-led

Continental Airlines to implement a fingerprint ID system to augment their automated

employee time and attendance recording system. The company expanded the system from

Control Module after it saved an estimated $100,000 in the first year. This led to the bar

code readers.

It is a much common sight to see a bar code reader in the companies. These are

used to check with the employees identification. The employees swipe the card in the

provided slot. Then the access is given after checking the authenticity of the card. This

was a substitute to the security and emerged as a new technique in access control. This

acted as a starting to the automation of the access control


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1.4 IntroductionThe concept of access control is brought about using a card, a corresponding

card reader and a control panel interfaced with the server. The card is a proximity card

with a unique identification number integrated in it. The reader reads the data and sends

it to the control panel, which is the micro controller. This controller checks the validity

of the data with the server, which bears the database. The server is loaded with the

details about the employee for that number.

The control panel checks whether he/she is allowed to enter the particular dooror not. If the employee is authentic, then he/she is allowed access in the particular

entrance.

The employees can be permitted in a given entrance as per his/her designation.

The access control is employed at this point.

In our project, the microcontroller is used to gain access through the door. The

controller used is AT89C51.

[9]


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Chapter 2: Block Diagram & Description

2.1 Block Diagram

2.2 Description of Block Diagram

[10]


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2.1 Block Diagram

[11]

XTAL218

XTAL119

ALE30

EA31

PSEN29

RST9

P0.0/AD039

P0.1/AD138

P0.2/AD237

P0.3/AD336

P0.4/AD435

P0.5/AD534

P0.6/AD633

P0.7/AD732

P1.01

P1.12

P1.23

P1.34

P1.45

P1.56

P1.67

P1.78

P3.0/RXD10

P3.1/TXD11

P3.2/INT012

P3.3/INT113

P3.4/T014

P3.7/RD17P3.6/WR16

P3.5/T115

P2.7/A1528

P2.0/A821

P2.1/A922

P2.2/A1023

P2.3/A1124

P2.4/A1225

P2.5/A1326

P2.6/A1427

U1

AT89C51

D7

14

D6

13

D5

12

D4

11

D3

10

D2

9

D1

8

D0

7

E

6

RW

5

RS

4

VSS

1

VDD

2

VEE

3

LCD1LM016L default password is " 1234".

1 2 3

4 5 6

7 8 9

0 #

1 2 3

A

B

C

D

* = Backspace

# = Enter

SCK6

SDA5

WP7

A01

A12

A23

U2

24C32A

D1LED-BLUE

LS1

SOUNDER

C1

33p

D1(A)

X1CRYSTAL

C2

33p


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2.2 Description of Block Diagram

Consider a case of one research institute where there are three kinds of

employs. One is clerk and peon. Second one is junior scientists and the last one is

senior scientists.

Entry to company main door should be allowed to every person. General

research work space is only for junior scientists and senior scientists and finally only

senior scientists can access high profile research work space.

.

Controller receives this id then compares availability and priority of this id, if

they are matched it allow the access to the user.

[12]

If all information is matched then Access Granted message is displayed to

LCD otherwise Invalid Pssword.


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Chapter 3: Hardware Design

3.1 Microcontroller AT89C51

3.2 LCD Display

3.3 Relay Interface

3.4 Buzzer

3.5 EEPROM

3.6 Power Supply

[13]


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Microcontroller

Definition :

An embedded microcontroller is chip which has a computer processor with all its

support functions (clock & reset), memory (both program and data), and I/O(including bus

interface) built in to the device. These built in function minimize the need for external circuits

and devices to be designed in the final application.

Types of Microcontroller

Creating application for microcontrollers is completely different than any other

development job in computing and electronics. In most other application one probably have a

number of subsystems and interface already available for his/her use. This is not the case with

a microcontroller where one is responsible for-

Power distribution

System clocking

Interface design and wiring

System programming

Application programming

Device programming

[14]

Before selecting a particular device for an application, its important to understand what

the different option and features are and what they can mean with regard to developing

application.


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Embedded Microcontroller

When all the hardware required to run the application is provided on the chip,

it is refer to as an embedded microcontroller. All that is typically required to operate

the device is power, reset, and a clock. Digital I/O pins are provided to allow

interfacing with external devices.

External Memory Microcontroller

Sometimes, the program memory is insufficient for an application or , during

debug; a separate ROM(or even RAM) would make the work easier. Some

microcontrollers including the 8051 allow the connection of external memory.

An external memory microcontroller seems to primarily differ from a

microprocessor in the areas of built in peripheral features. These features could

include memory device selection (avoiding the need for external address decoders or

DRAM address multiplexers), timers, interrupt controllers, DMA, and I/O devices

like serial ports.

[15]


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Features of AT89C51

Compatible with MCS-51 Products

4K Bytes of In-System Reprogrammable Flash Memory

Endurance: 1,000 Write/Erase Cycles

Fully Static Operation: 0 Hz to 24 MHz

Three-level Program Memory Lock

128 x 8-bit Internal RAM

32 Programmable I/O Lines

Two 16-bit Timer/Counters

Six Interrupt Sources Programmable Serial Channel

Low-power Idle and Power-down Modes

Description

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with

4K

bytes of Flash programmable and erasable read only memory (PEROM). The device

is manufactured using Atmels high-density non-volatile memory technology and is

compatible with the industry-standard MCS-51 instruction set and pin out. The on-

chip flash allows the program memory to be reprogrammed in-system or by a

conventional non-volatile memory programmer. By combining a versatile 8-bit CPU

with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer

which provides a highly-flexible and cost-effective solution to many embeddedcontrol applications

[16]


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PIN DIAGRAM OF 8051

BLOCK DIAGRAM

[17]


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3.2 LCD Display Interface

The dot-matrix liquid crystal display controller and driver LSI displays

alphanumeric, characters, and symbols. It can be configured to drive a dot-matrix

liquid crystal display under the control of a 4 or 8-bit microprocessor. Since all the

functions such as display RAM, character generator, and liquid crystal driver,

required for driving a dot-matrix liquid crystal display are internally provided on one

chip, a minimal system can be interfaced with this controller/driver. A single

HD44780U can display up to two 8-character lines (16 x 2).

A 16 x 2 line LCD module to display user information. Micro controller sendthe data signals through pin 11 through 18(RC0-RC3) and control signal through 4,6

and 7 of the micro controller. Pin no 3 of the LCD is used to control the contrast by

using preset PR1.

[18]


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3.3 Relay Interface

A single pole dabble throw (SPDT) relay is connected to port RB1 of the

microcontroller through a driver transistor. The relay requires 12 volts at a current of

around 100ma, which cannot provide by the microcontroller. So the driver transistor

is added. The relay is used to operate the external solenoid forming part of a locking

device or for operating any other electrical devices. Normally the relay remains off.

As soon as pin of the microcontroller goes high, the relay operates. When the relay

operates and releases. Diode D2 is the standard diode on a mechanical relay to

prevent back EMF from damaging Q3 when the relay releases. LED L2 indicates

relay on.

[19]


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3.4 Buzzer

A buzzer connected to port RB0 of the micro controller through a driver

transistor. The buzzer requires 12 volts at a current of around 50ma, which cannot

provided by the micro controller. So the driver transistor is added. The buzzer is

used to audible indication for valid user and error situation and alarm mode. As soon

as pin of the micro controller goes high, the buzzer operates.

[20]


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3.5 EEPROM :

EEPROM (also written E2PROM and pronounced "e-e-prom," "double-e prom" or simply

"e-squared") stands forElectrically Erasable ProgrammableRead-Only Memory and is a type

ofnon-volatile memory used in computers and other electronic devices to store small

amounts of data that must be saved when power is removed, e.g., calibration tables or device

configuration.

When larger amounts of static data are to be stored (such as in USB flash drives) a specific

type of EEPROM such as flash memory is more economical than traditional EEPROM

devices. EEPROMs are realized as arrays offloating-gate transistors.

EEPROM is user-modifiable read-only memory (ROM) that can be erased and

reprogrammed (written to) repeatedly through the application of higher than normal electrical

voltage generated externally or internally in the case of modern EEPROMs. EPROM usually

must be removed from the device for erasing and programming, whereas EEPROMs can be

programmed and erased in circuit. Originally, EEPROMs were limited to single byte

operations which made them slower, but modern EEPROMs allow multi-byte page

operations. It also has a limited life - that is, the number of times it could be reprogrammed

was limited to tens or hundreds of thousands of times. That limitation has been extended to a

million write operations in modern EEPROMs. In an EEPROM that is frequently

reprogrammed while the computer is in use, the life of the EEPROM can be an important

design consideration. It is for this reason that EEPROMs were used for configuration

information, rather than random access memory.

Here, we are using AT 24C32A EEPROM because of that design configuration.

[21]
http://en.wikipedia.org/wiki/Non-volatile_memoryhttp://en.wikipedia.org/wiki/USB_flash_drivehttp://en.wikipedia.org/wiki/Flash_memoryhttp://en.wikipedia.org/wiki/Floating-gate_transistorhttp://en.wikipedia.org/wiki/Floating-gate_transistorhttp://en.wikipedia.org/wiki/Flash_memoryhttp://en.wikipedia.org/wiki/USB_flash_drivehttp://en.wikipedia.org/wiki/Non-volatile_memory


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FEATURES :

Voltage operating range: 4.5V to 5.5V

- Maximum write current 3 mA at 5.5V

- Standby current 1 A typical at 5.0V

2-wire serial interface bus, I2C- compatible

100 kHz and 400 kHz compatibility

Self-timed ERASE and WRITE cycles

Power on/off data protection circuitry

Hardware write protect

1,000,000 Erase/Write cycles guaranteed

32-byte page or byte write modes available

Schmitt trigger filtered inputs for noise suppression

Output slope control to eliminate ground bounce

2 ms typical write cycle time, byte or page

Up to eight devices may be connected to the

same bus for up to 256K bits total memory

Electrostatic discharge protection > 4000V

Data retention > 200 years

8-pin PDIP and SOIC packages

Temperature ranges

DESCRIPTION :

[22]

The Microchip Technology Inc. 24C32A is a 4K x 8(32K bit) Serial Electrically Erasable

PROM. It has been developed for advanced, low power applications such as personal

communications or data acquisition. The 24C32A also has a page-write capability of up to 32

bytes of data. The 24C32A is capable of both random and sequential reads up to the 32K

boundary. Functional address lines allow up to eight 24C32A devices on the same bus, for up

to 256K bits address space. Advanced CMOS technology and broad voltagerange make thisdevice ideal for low-power/low-voltage, nonvolatile code and data applications. The2 4C32A

is available in the standard 8-pin plastic DIPand both 150 mil and 200 mil SOIC packaging.


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- Commercial (C): 0C to 70C

- Industrial (I): -40C to +85C

- Automotive (E): -40C to +125C

PACKAGE TYPES :

PDIP :

SOIC :

[23]


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BLOCK DIAGRAM :

PIN DESCRIPTIONS :

A0, A1, A2 Chip Address Inputs : The A0..A2 inputs are used by the 24C32A for multiple

device operation and conform to the 2-wire bus standard. The levels applied to these pins

define theaddress block occupied by the device in the addressmap. A particular device is

selected by transmitting thecorresponding bits (A2, A1, A0) in the control byte

[24]

SDA Serial Address/Data Input/Output : This is a Bi-directional pin used to transfer

addressesand data into and data out of the device. It is an opendrain terminal, therefore the

SDA bus requires a pullupresistor to VCC (typical 10K for 100 kHz, 2 K for400 kHz)

For normal data transfer SDA is allowed to change onlyduring SCL low. Changes duringSCL HIGH arereserved for indicating the START and STOP conditions.


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SCL Serial Clock : This input is used to synchronize the data transfer fromand to the

device.

WP : This pin must be connected to either VSS or VCC. If tied to VSS, normal memory

operation is enabled (read/write the entire memory 000-FFF). If tied to VCC, WRITE

operations are inhibited. The entire memory will be write-protected. Read operations are not

affected.

READ OPERATION :Read operations are initiated in the same way as writeoperations

with the exception that the R/W bit of theslave address is set to one. There are three basic

typesof read operations: current address read, random read,and sequential read.

Current Address Read : The 24C32A contains an address counter that maintains the

address of the last word accessed, internallyincremented by one. Therefore, if the previous

access (either a read or write operation) was to address n (n isany legal address), the next

current address read operation would access data from address n + 1. Uponreceipt of the slave

address with R/W bit set to one, the24C32A issues an acknowledge and transmits theeight

bit data word. The master will not acknowledgethe transfer but does generate a stop

condition and the24C32A discontinues transmission.

Random Read : Random read operations allow the master to accessany memory location in

a random manner. To performthis type of read operation, first the word address must be set.

This is done by sending the word address to the24C32A as part of a write operation (R/W bitset tozero). After the word address is sent, the master generates a start condition following the

acknowledge. This terminates the write operation, but not before the internal address pointer

is set. Then the master issues thecontrol byte again but with the R/W bit set to a one. The

24C32A will then issue an acknowledge and transmitthe 8-bit data word. The master will not

acknowledgethe transfer but does generate a stop condition whichcauses the 24C32A to

discontinue transmission.

Contiguous Addressing Across Multiple Devices

The device select bits A2, A1, A0 can be used to expand the contiguous address space for up

to 256K bits by adding up to eight 24C32A's on the same bus. In this case, software can use

A0 of the control byte as address bit A12, A1 as address bit A13, and A2 as address bit A14.

Sequential Read :

[25]

Sequential reads are initiated in the same way as a random read except that after the 24C32A

transmits the first data byte, the master issues an acknowledge as opposed to the stop

condition used in a random read. This acknowledge directs the 24C32A to transmit the nextsequentially addressed 8-bit word . Following the final byte transmitted to the master, the

master will NOT generate an acknowledge but will generate a stop condition. To provide


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sequential reads the 24C32A contains an internal address pointer which is incremented by

one atthe completion of each operation. This address pointer allows the entire memory

contents to be serially read during one operation. The internal address pointer will

automatically roll over from address 0FFF to address 000 if the master acknowledges the byte

received from the array address 0FFF.

WRITE OPERATION :

[26]

Byte Write : Following the start condition from the master, the control code (four bits), the

device select (three bits), andthe R/W bit which is a logic low are clocked onto the bus by the

master transmitter. This indicates to theaddressed slave receiver that a byte with a word

address will follow after it has generated an acknowledge bit during the ninth clock cycle.

Therefore, thenext byte transmitted by the master is the high-orderbyte of the word address

and will be written into theaddress pointer of the 24C32A. The next byte is theleast

significant address byte. After receiving another acknowledge signal from the 24C32A the

masterdevice will transmit the data word to be written into theaddressed memory location.

The 24C32A acknowledges again and the master generates a stop condition. This initiates the

internal writecycle, and during this time the 24C32A will not generate acknowledge signals.


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Page Write : The write control byte, word address and the first databyte are transmitted to

the 24C32A in the same way asin a byte write. But instead of generating a stop condition,

the master transmits up to 32 bytes which are temporarily stored in the on-chip page buffer

and will bewritten into memory after the master has transmitted astop condition. After

receipt of each word, the five loweraddress pointer bits are internally incremented by one.Ifthe master should transmit more than 32 bytes priorto generating the stop condition, the

address counterwill roll over and the previously received data will beoverwritten. As with

the byte write operation, once thestop condition is received, an internal write cycle will

begin.

3.6 Power supply

Two supply voltages are required for the telephone remote system circuit. A transformer is

used for taking a 12V supply. This 12V is connected to bridge rectifier for converting it into

DC supply. The input coming from rectifier unit contains AC voltage component. This is

filtered out with the help of high capacity capacitors connected in parallel. Here U3 and U4

are supplied with a regulated 5V from a 7805(U2) fixed voltage regulator.The unregulated

voltage of approximately 12V is required for relay and buzzer driving circuit. LEDs L1

indicate power supply status. LED has a current limiting resister in series.

[27]


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[28]


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Chapter 4: Software Design

4.1 LCD Module

[29]

4.2 Process chart


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4.1 LCD MODULE

[30]

InitializationofLCD:

4bit&2linedisplay

DisplayON&

Cursorblinking

Cleardisplayscreen

Incrementcursor

Cursorbeginningof

1stline

Givinginputin

theform

of

textb RS=1

DisplaysWaitingforuser

code

STARTSTART

1


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4.2 Process Chart

[31]

Start

EEPROM

8051

Microcontroller

Check Code

Availability

LCD Display

Access Granted

LCD Display

Invalid User

RelayOn

DoorOpen

Relay On

Door O en

YesNo

Cursorbeginningof

2nd

linebyRS=0

Displaysusernumber,RFIDcodeBy

RS=1

1


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Chapter 5: Testing and Results

5.1 Hardware and Setup

5.2 LCD Test

5.3 Result

[32]


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5.1 HARDWARE SET-UP The power supply is provided first to the hardware and through voltage

regulator, the circuit components receive their proper supply voltage.

After that, the LCD displays the required BCD code and asks to the person to

show the tag.

The code is received by the module and checks the code availability.

For correct code, LCD displays the CORRECT PASSWORD

For wrong code, LCD displays INVALID PASSWORD.

5.2 LCD TESTINGLCD is used in 4 bit mode, so the 8 bit data is moved in the form of nibbles to

the LCD one by one. When LCD was tested by supplying it with proper location, it

gave correct display according to the LCD programming with cursor on and blinking

and cursor incrementing to write. LCD displays persons data base and the final

result.

5.3 RESULT

The project works for the door access by checking the password in EEPROM

and displays the results accordingly.

[33]


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Chapter 6: Source code in c-language

#include

#define EE_SCL P1_0

#define EE_SDA P1_1

#define LCD_E P1_7

#define LCD_RW P1_6

#define LCD_RS P1_5

#define LCD_DATA P3

#define buzz P0_3

#define led P1_2

void cmnwrt(int);

void datawrt(char);

char keypad_refresh();

void init();

void delay(unsigned i);

void get_sntnc(char *);

void print_msg(char*,char);

void EE_write(unsigned int, char);

char EE_read(unsigned int);

void EE_strt();

void EE_stop();

char EE_shin();

void EE_shout(char);

[34]

//----------------------------------------


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//----------------------------------------

int main(){

char tmp[17],i,j;

init();

cmnwrt(0x80);

led=1;

while(1){

if(EE_read(0) != 'p' || EE_read(1) != '='){

np:

cmnwrt(1);

print_msg("Enter new pass:\0",0x80);

get_sntnc(tmp);

EE_write(0,'p');

EE_write(1,'=');

for(i=0; tmp[i]; i++)

EE_write(i+2,tmp[i]);

EE_write(i+2,0);

}

rpa:

cmnwrt(1);

print_msg("Enter the pass:\0",0x80);

get_sntnc(tmp);

for(i=0,j=0;;i++){

if(tmp[i] != EE_read(i+2)){

j=-1;

[35]

break;


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}

if(!tmp[i])

break;

}

cmnwrt(1);

if(j==-1)

{

print_msg("Pass is wrong!\0",0x80);

led=1;

buzz=1;

delay(5000);

buzz=0;

goto rpa;

}

else

{

print_msg("Pass is right!\0",0x80);

led=0;

buzz=0;

delay(5000);

led=1;

}

cmnwrt(1);

print_msg("*=change pass\0",0x80);

[36]

print_msg("#=back\0",0xc0);


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ka:

do

i=keypad_refresh();

while(i==-1);

if(i==0x3a)

goto np;

else if(i==0x3c)

goto rpa;

else

goto ka;

}

}

//------------------------------------

//------------------------------------

void print_msg(char *msg, char line){

char i;

cmnwrt(line);

for(i=0; *(msg+i); i++)

datawrt(*(msg+i));

}

//------------------------------------

//------------------------------------

char keypad_refresh(){

[37]

char tmp,row,cl;


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P2 = 0xf0;

if(!P2_4)

row = 0;

else if(!P2_5)

row = 1;

else if(!P2_6)

row = 2;

else if(!P2_7)

row = 3;

else

return -1;

P2 = 0xff;

P2 = 0x0f;

if(!P2_2)

cl = 0;

else if(!P2_1)

cl = 1;

else if(!P2_0)

cl = 2;

else

return -1;

[38]


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tmp = row*3+cl+1;

if(tmp == 11)

tmp = 0;

return tmp|0x30;

}

//--------------------------------------------------

//--------------------------------------------------

void get_sntnc(char *str) {

char i,j,z;

for(i=0; i


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do

j = keypad_refresh();

while(j==-1);

if(j==0x3c){

*(str+i) = 0;

break;

}else if(j==0x3a){

if(i>0){

i--;

*(str+i) = 0;

}

}else{

if(i


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}

}

//--------------------------------------------------

//--------------------------------------------------

void delay(unsigned i) {

TMOD = 1;

for (;i>0;i--) {

TH0 = 0xFc; //0xFFFF - 0xFc17 = 1000 (decimal) -> 1ms for 12MH

crystal

TL0 = 0x17;

TR0 = 1;

while(!TF0);

TR0 = 0;

TF0 = 0;

}

}

//--------------------------------------------------

//--------------------------------------------------

void cmnwrt(int cmn) {

LCD_DATA = cmn;

LCD_RS = 0;

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LCD_RW = 0;


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LCD_E = 1;

LCD_E = 0;

delay(2);

}

void datawrt(char ch) {

LCD_DATA = ch;

LCD_RS = 1;

LCD_RW = 0;

LCD_E = 1;

LCD_E = 0;

delay(2);

}

//---------------------------------------------------

//---------------------------------------------------

//Write into EEPROM

void EE_write(unsigned int addr, char dta){

char chtmp;

CY = 0;

EE_strt();

EE_shout(0xA0);

chtmp = addr>>8;

EE_shout(chtmp);

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chtmp = addr;


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void EE_strt() {

EE_SDA = 1;

EE_SCL = 1;

EE_SDA = 0;

EE_SCL = 0;

}

//Stop

void EE_stop() {

EE_SCL = 0;

EE_SDA = 0;

EE_SCL = 1;

EE_SDA = 1;

}

//Shift out

void EE_shout(char sho) {

unsigned char i,j;

for (j=0, i=0; i


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CY = 0;

EE_SDA = CY;

EE_SCL = 1;

j = j; //delay

EE_SCL = 0;

}

EE_SDA = 1;

EE_SCL = 1;

j=j; //delay

CY = EE_SDA;

EE_SCL = 0;

}

//Shift in

char EE_shin() {

char i,shi = 0;

EE_SDA = 1;

for (i=0; i


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}

EE_SDA = 1;

EE_SCL = 1;

i=i; //delay

EE_SCL = 0;

return shi;

}

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Chapter 7: Applications ,Advantages & Disadvantages

7.1 Application

7.2 Advantage

7.3 Disadvantage

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7.1 Application

The term access control refers to the practice of restricting entrance to a

property, a building or a room to authorized persons. Integrated and controller based

access control numeric and alphabetic keyless entry keypads with programmable

features for the access control of single openings. The various applications are as

follows.

Industrial facilities

Commercial buildings

Airports, civil transportation Convention halls

Psychiatric care centres

Museums and fine art galleries

Ware houses

Technology centres

Government and military

Long term care facilities

Drug rehabilitation centres

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7.2 Advantage

Use of RFID technology can increase business productivity and reduce

associated costs. To ensure that companies benefit from the advantages RFID

provides it is important to understand how to adopt this technology. By analyzing

current practices and procedures eight main areas of benefit can be identified. These

are:

Improved Productivity and Cost Avoidance.

Decreased Cycle Time and Taking Costs Out.

Reduced Rework.

Reduced Business Risk & Control of Assets.

Improved Security and Service.

Improved Utilization of Resources.

Increased Revenues.

Exception Management.

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7.3 Disadvantage

The disadvantages are that, when there is a necessity of providing control at many

locations inside the company, a person at each point will not be an economical way of

implementing it.

Then came were the punch cards. Employees possess cards, which are punched when

they enter into the building. But it had disadvantages. Workers started to practice buddy

punching, for their co-workers.

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DOC B.1 Security 2

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Transcript of DOC B.1 Security 2