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CHAPTER 1

INTRODUCTION

1.1 RFIDRFID stands for Radio-Frequency IDentification. The acronym refers to small

electronic devices that consist of a small chip and an antenna. The chip typically is

capable of carrying 2,000 bytes of data or less.

It is a generic term that is used to describe a system that transmits the identity (in the

form of a unique serial number) of an object or person wirelessly, using radio waves. It's

grouped under the broad category of Automatic Identification Technologies.

Auto-ID technologies include bar codes, optical character readers and some

biometric technologies, such as retinal scans. The auto-ID technologies have been used to

reduce the amount of time and labor needed to input data manually and to improve data

accuracy.

Some auto-ID technologies, such as bar code systems, often require a person to

manually scan a label or tag to capture the data. RFID is designed to enable readers to

capture data on tags and transmit it to a computer systemwithout needing a person to

be involved.

1.2 LOCATION BASED SERVICES

Location-based services are a general class of computer program-level services

used to include specific controls for location and time data as control features in

computer programs. As such (LBS) is an information and has a number of uses in Social

Networking today as an entertainment service, which is accessible with mobile

devices through the mobile network and which uses information on the geographical

position of the mobile device. This has become more and more important with the

expansion of the smart phone and tablet markets as well.

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Fig 1.1:Classification on Location Based Systems

Some examples of location-based services are:

Recommending social events in a city Requesting the nearest business or service, such as an ATM or restaurant Turn by turn navigation to any address Locating people on a map displayed on the mobile phone Receiving alerts, such as notification of a sale on gas or warning of a traffic jam Location-based mobile advertising Asset recovery combined with active RF to find, for example, stolen assets in

containers where GPS would not work

Games where your location is part of the game play, for example your movementsduring your day make your avatar move in the game or your position unlocks

content.

Real-time Q&A revolving around restaurants, services, and other venues.

1.3 GAINING IMPORTANCE OF RFID

Even though it has been used for more than seventy years (e.g., RFID was used

in World War II for identifying enemy aircrafts), it is only now that this technology is re-

emerging as an important communication paradigm that claims to revolutionize

inventory and automation processes.

In an international study undertaken by IT consultancy LogicaCMG, the majority of the

companies interviewed in the Netherlands, UK, Ireland, Germany, France and Belgium,

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gave RFID top priority in terms of planned IT investment. The study shows that half of

the 50 companies interviewed in Europe have or are planning to deploy RFID pilot

projects throughout 2004, with the vast majority planning to start implementing the

technology within the next three years. The RFID implementations will lead to an

irreversible process in the retail market.

1.4 ADVANTAGES OF RFID

RFID technology does not require line-of-sight reading: Unlike a bar code, an

RFID tag can be read through other materials (though some materials may cause

problems). Theoretically, this means that you could take a pallet of mixed products, all of

which contain individual RFID tags, and have an RFID reader read all the tags within the

palletized load without having to physically move any of the materials or open any cases.

RFID tags can hold more data than bar code: As the data storage capacity of

RFID tags increase, so does the cost of the tags. Therefore, it is likely that many RFID

tags will not hold any more data than a bar code.

RFID tag data can be changed or added to as a tag passes through specific

operations: Read-only tags are much less expensive than read/write tags. Therefore,

limited use of this functionality is likely.

RFID tags are more effective in harsh environments where bar code labels have

problems: RFID tags can be sealed within a plastic enclosure eliminating many of the

problems that plague bar codes in harsh environments where they are exposed to

chemicals, heat, abrasion, dirt and grease buildup, etc.

A large number of RFID tags can be read almost instantaneously: This brings us

back to the palletized load scenario where the load contains a large quantity of products,

each with its own RFID tag. Though it may seem as though the tags are all read at once,

they are actually read sequentially (one at a time), however, this happens so fast that it is

virtually imperceptible.

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1.5 DISADVANTAGES OF RFID

Cost: This is the biggest hurdle to RFID tags replacing bar codes for item-level tracking

of low-cost products. We can produce a bar code on an item for less than 1 cent, yet the

most optimistic proponents of RFID are still hoping for 5 or 10-cent RFID tags

sometime in the future (this may be years away). And even if we get 5-cent tags, that is

still a significant cost to add to the manufactured cost of low-cost consumer goods. And

even with higher-cost products, or case and pallet level tracking, the benefits of RFID

must be greater than this additional cost. The funniest thing is that cost of these tags will

not reduce until they are widely used, and they wont be widely used unless their cost

decreases.

RFID signals may have problems with some materials: Metals and liquids can cause

problems when trying to read RFID tags. Tag placement is becoming a science in and of

itself since depending on the product even a case-level RFID tag may have to be placed

in a specific location on the case and cases stacked in a specific orientation to get a

consistent read.

Though RFID does not require of line-of-sight, it is also not restricted by it. With the

proper bar code equipment, we can selectively read a single bar coded case on a shelf

more than ten feet away. We cant do that with RFID since an RFID reader will read all

tags within its range. Even though you can get directional RFID readers, they are still not

as selective as a visual device (bar code scanner). There are still many warehouse

applications that require this line-of-site capability.

RFID can fail tags: The unique issue with RFID failure is the automated nature of RFID

optimized processes. If you have a pallet of materials with RFID tags and one of the

RFID tags is damaged, it is difficult to recognize it.

RFID programming speed: The smart label scenario (using labels with integrated RFID

chips) seems to be the most likely one for mass utilization of RFID for case and unit

tracking of inventory. Unfortunately, it takes more time to print, program, and verify an

RFID enabled label than to simply print a bar code label. In addition, RFID smart labels

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seem to have some serious quality problems. There have been average failure rates

(inability to properly program and read the tag) of anywhere from 10% to 30%.

For automated print-and-apply applications, this could be a serious problem.

RFID standards are still being developed: Nobody would want to invest in an RFID

system that is based on soon-to-be obsolete specs. Most RFID systems currently in place

are based upon proprietary technology where the readers are designed to only read RFID

tags from a specific manufacturer. When compared to bar code technology, where

standards have been in place for decades, most bar code scanners are designed to read all

standard bar code symbologies.

1.6 PROBLEMS WITH RFIDRFID has been implemented in different ways by different manufacturers; global

standards are still being worked on. It should be noted that some RFID devices are never

meant to leave their network (as in the case of RFID tags used for inventory control

within a company). This can cause problems for companies.

Consumers may also have problems with RFID standards. For example, ExxonMobil'sSpeed Pass system is a proprietary RFID system; if another company wanted to use the

convenient Speed Pass (say, at the drive-in window of your favorite fast food restaurant)

they would have to pay to access it - an unlikely scenario. On the other hand, if every

company had their own "Speed Pass" system, a consumer would need to carry many

different devices with them.

1.6.1 RFID systems can be easily disrupted

Since RFID systems make use of the electromagnetic spectrum (like Wi-Fi networks or

cell phones), they are relatively easy to jam using energy at the right frequency.

Although, this would be an inconvenience for consumers in stores (longer waits at the

checkout), it could be disastrous in other environments where RFID is increasingly used,

like hospitals or in the military in the field.

Also, active RFID tags (those that use a battery to increase the range of the system) can

be repeatedly interrogated to wear the battery down, disrupting the system.

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1.6.2RFID Reader Collision

Reader collision occurs when the signals from two or more readers overlap. The tag is

unable to respond to simultaneous queries. Systems must be carefully set up to avoid this

problem; many systems use an anti-collision protocol (also called a singulation

protocol. Anti-collision protocols enable the tags to take turns in transmitting to a reader.

1.6.3RFID Tag Collision

Tag collision occurs when many tags are present in a small area, but since the read time

is very fast, it is easier for vendors to develop systems that ensure that tags respond one

at a time.

1.6.4Security, privacy and ethics problems with RFID

The contents of an RFID tag can be read after the item leaves the supply chain. An RFID

tag cannot tell the difference between one reader and another. RFID scanners are very

portable; RFID tags can be read from a distance, from a few inches to a few yards. This

allows anyone to see the contents of your purse or pocket as you walk down the street.

Some tags can be turned off when the item has left the supply chain.

1.6.5 Attaching Issues

RFID tags are difficult to for consumers to remove; some are very small (less than a half-

millimeter square and as thin as a sheet of paper) - others may be hidden or embedded

inside a product where consumers cannot see them. New technologies allow RFID tags to

be "printed" right on a product and may not be removable at all.

1.6.6 Others

RFID tags can be read without your knowledge

Since the tags can be read without being swiped or obviously scanned, anyone with an

RFID tag reader can read the tags embedded in your clothes and other consumer products

without your knowledge. For example, you could be scanned before you enter the store,

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just to see what you are carrying. You might then be approached by a clerk who knows

what you have in your backpack or purse, and can suggest accessories or other items.

RFID tags can be read from greater distances with a high-gain antenna

For various reasons, RFID reader/tag systems are designed so that distance between the

tag and the reader is kept to a minimum (see the material on tag collision above).

However, a high-gain antenna can be used to read the tags from much further away,

leading to privacy problems.

RFID tags with unique serial numbers could be linked to an individual credit card

number

At present, the Universal Product Code (UPC) implemented with barcodes allows each

product sold in a store to have a unique number that identifies that product. Work is

proceeding on a global system of product identification that would allow each individual

item to have its own number. When the item is scanned for purchase and is paid for, the

RFID tag number for a particular item can be associated with a credit card number.

1.7 APPLICATIONS OF RFID Asset Tracking Security People Tracking Document tracking Library Healthcare Animal Tracking Work-in-Process Container/ Yard Management Inventory Management

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1.7.1 SECURITYAn alarm car uses RFID system to communicate between the remote control (the

Tag) and the car alarm system (the Verifier), farther more a thief (an Adversary) may or

may not listen to the communications.

The scenario is as follows:

The Tag (remote control) sends an encrypted request to the Verifier (car) to open

the car. The car processes and decrypts the request and composed an answer, if the

request is genuine then "Open" message is sent back. If it is not, a "Do Not Open"

message is sent. The thief may or may not listen to the communications, and based on

them compose a false message that will be sent to the car in order to get an "Open"

message back.

Fig 1.2: Pictorial representation of the scenario

1.7.2 PHARMACEUTICAL INDUSTRY

The pharmaceutical industry is currently looking for a better way of

monitoring their pharmaceuticals not only in the supply-chain but once the prescription is

at home in the medicine cabinet for which RFID is currently being looked at as the

answer to this question.

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Fig 1.3: RFID Placed Behind Label on Pharmaceutical

There are many benefits for the pharmaceutical industry to incorporate RFID into their

supply chain. The first being stocking drugs is a difficult task that requires more

information and organization than is the case with any other item. Furthermore a more

efficient supply-chain would save time and money. With all these reasons aside there is

till a greater reason and that is patient safety. With a more accurate way of error

prevention with drugs these should be enough of a reason for drug companies to adopt

RFID into their supply chain. Companies like AstraZeneca, who have already adopted

RFID into its supply chain, have had great success with dispensing over 30 Million RFID

enabled syringes of Diprivan.

The main difference between the food industry and the pharmaceutical industry is one of

priority. The food industry is interested in placing RFID on pallets and cases at the

request of the retailers, while the pharmaceutical industry is mainly interested in placing

RFID on individual items, bottles and packages. Unlike the food industry its first concern

is patient safety and wellbeing. This would mean RFID that can be taken with the patient

to their home, office, or doctors office and will still function and be able to help them

with their medical needs.

However, one of the biggest reasons some pharmaceuticals have incorporated RFID is to

help combat counterfeiting. By incorporating RFID pharmacies would be able to

eliminate counterfeiting by ensuring that every drug was indeed the correct drug.

Currently most manufacturers are using High-frequency RFID instead of its cheaper

counterpart Ultra-high frequency RFID due to the small size they can be manufactured.

This allows RFID tags to be placed on individual blister packs which could gather more

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information about a medication; if its being taken on time, if it has been tampered with,

or what environment each pill experienced during transportation.

1.7.3 IDENTIFICATION

RFID tags for animals represent one of the oldest uses of RFID technology. Originally

meant for large ranches and rough terrain, since the outbreak of mad-cow disease, RFID

has become crucial in animalidentification management. An implantable RFID tag or

transpoder can also be used for animal identification. The transponders are more well-

known as passive RFID technology, or "chips" on animals. The Canadian Cattle

Identification Agency began using RFID tags as a replacement for barcode tags.

Currently CCIA tags are used in Wisconsin and by US farmers on a voluntary basis.

The USDA is currently developing its own program

Fig 1.4: A sheep with an ear tag.

Fig 1.5: Animal management using RFID technology

Implantable RFID chips designed for animal tagging are now being used in humans. An

early experiment with RFID implants was conducted by British professor
http://en.wikipedia.org/wiki/Animal_identificationhttp://en.wikipedia.org/wiki/Animal_identificationhttp://en.wikipedia.org/wiki/Animal_identificationhttp://en.wikipedia.org/wiki/File:Santa_Gertrudis.jpghttp://en.wikipedia.org/wiki/File:Sheep's_face,_Malta.jpghttp://en.wikipedia.org/wiki/File:Santa_Gertrudis.jpghttp://en.wikipedia.org/wiki/File:Sheep's_face,_Malta.jpghttp://en.wikipedia.org/wiki/Animal_identification

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CHAPTER 2

PROJECT OVERVIEW

2.1 SCHEMATIC LAYOUT

Transmitter:

Fig 2.1: Circuit Diagram of Transmitter

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Receiver:

Fig 2.2: Circuit Diagram of Receiver

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2.2 CIRCUIT DESCRIPTION

Since the main intention of this project is to design a Location

Based System using RFID. In order to fulfill this application there are few steps that has

been performed i.e.

1) Design the power supply for the entire circuit2) Selection of microcontroller that suits our application3) Selection of MAX2324) Selection of LCD

Complete studies of all the above points are useful to develop this project

2.2.1 POWER SUPPLY SELECTION

In-order to work with any components basic requirement is power supply.

In this section there is a requirement of two different voltage levels. Those are

1)

5V DC Power Supply2) 12V DC Power Supply

Now the aim is to design the power supply section which converts 230V

AC into 5V DC. Since 230V AC is too high to reduce it to directly 5V DC,

therefore we need a step-down transformer that reduces the line voltage to certain

voltage that will help us to convert it into a 5V DC. Considering the efficiency

factor of the bridge rectifier, we came to a conclusion to choose a transformer,

whose secondary voltage is 3 to 4V higher than the required voltage i.e. 5V. For

this application 0-12V transformers is used, since it is easily available in the

market.

The output of the transformer is 12V AC, it fed to rectifier that converts

AC to pulsating DC. As we all know that there are three kinds of rectifiers. They

are

1) Half-wave2) Full-wave and3) Bridge Rectifier

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Here we short listed to use Bridge Rectifier, because half wave rectifier

has we less in efficiency. Even though the efficiency of full wave and bridge rectifier are

the same, since there is no requirement for any negative voltage for our application, we

gone with bridge rectifier.

Since the output voltage of the rectifier is pulsating DC, in order to

convert it into pure DC we use a high value (1000UF / 1500UF) of capacitor in parallel

that acts as a filter. The most easy way to regulate this voltage is by using a 7805 voltage

regulator, whose output voltage is constant 5V DC irrespective of any fluctuation in line

voltage.

2.2.2 SELECTION OF MICROCONTROLLER

As we know that there are so many types of microcontroller families

that are available in the market. Those are

1) 8051 Family2) AVR Microcontroller Family3) PIC Microcontroller Family4) ARM Family

Basic 8051 family is enough for our application; hence we are not

concentrating on higher end controller families.

In order to fulfill our application basic that is AT89C51 controller is

enough. 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 section2) Pull-ups for ports (it is must for PORT0)3) Reset circuit4) Crystal circuit5) ISP circuit (for program dumping)6) EA/VPP pin is connected to Vcc

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PORT0 is open collector thats 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 timing pluses. In this project we are not using external memory

thats why EA/VPP pin in the microcontroller is connected to Vcc that indicates internal

memory is used for this application.

2.2.3 SELECTION OF MAX 232

When we want communicate GSM module with microcontroller then

we can use RS232 port. Serial Rs-232 (V.24) communication works with voltages(between 15V3V and used to transmit a binary1 and +3V +15V to transmit a

binary 0) which are not compatible with todays computer logic voltages. On the other

hand, classic TTL computer logic operates between 0V +5V (roughly 0V +0.8V

referred to as low for binary 0, +2V +5V for high binary 1). So MAX232 is used

to convert from TTL voltage level to RS 232 voltage levels.

2.2.4 SELECTION OF LCD

A liquid crystal display (LCD) is an electronically-modulated-optical device

shaped into a thin, flat panel made up of any number of color or filled monochrome

pixels with liquid crystals and arrayed in front of a light source (back light) or reflector.

In this project 1 LCD is used to display the GMS status.

2.3 FUNCTIONING OF THE CIRCUIT

A power supply of 230V AC is given to the step down transformer. The purpose of this

step down transformer is to reduce the magnitude of the incoming current to the required

range. Hence, that 230V AC is stepped down to 12V AC supply which is the desired

range for our circuit. But, to drive this circuit DC current is essential. Hence, another

problem arises here. To overcome this bridge rectifier is used. A bridge rectifier function

is to convert AC current into Dc current of the same magnitude. Hence, when 12v AC is

given as input to a bridge rectifier output is 12V DC. But actually we need only 5v of DC

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to drive the circuit. The reason why a 5v step down transformer is not used is that when

such a high power is stepped down to a low value there is a chance of not getting the

exact desired value. Even a slight fluctuation in the current cannot be tolerated by the

circuit, it may even affect the system output .Hence a voltage rectifier is used the 12V

DC supply is given to the voltage regulator to get exactly 5v of dc. This is supplied to the

entire circuit including the RFID reader. As the power is supplied, LCD glows. This

indicates that the system is now ready to be used. As per the program already feeded into

the controllers as soon as the LCD glows the start message is displayed on it. When an

RFID tag is bought into the range of RFID reader, the tag is recognized by the reader.

Each tag has its own unique code just like each person has a name to recognize. The code

of each tag is like its name to be recognized by the controller. As the tag is recognized

the code of the tag is sent to the microcontroller. Microcontroller cannot accept analog

signals. So, MAX 232 is used in between which converts analog signals into digital

signals. The digital signal has to be sent bit by bit to the controller. For this serial

communication purpose RS-232 is used. The program which is dumped into the

microcontroller is executed. As the Database of the user list is already entered into the

controller. If the code of the tag is authorized then, the information present in that tag is

displayed on the LCD. This information is passed onto the receiver end by means of an

antenna. The same information is displayed on the receiver side also. Hence, the data is

displayed on the LCD at the receiver end.

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CHAPTER 3

BLOCK DIAGRAM AND ITS DESCRIPTION

3.1 BLOCK DIAGRAM

TRANSMITTER

RECEIVER

Fig 3.1: Block Diagram of Transmitter

POWER SUPPLY

RF TRANSMITTER

LCD DISPLAY

MICRO-

CONTROLLER

AT89S52

RFID READER

RFID TAG

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Fig 3.2: Block Diagram of Receiver

3.2 POWER SUPPLY

Power is supplied through a transformer which supplies 12V A.C. This current is

then passed through a rectifier circuit to convert ac into dc. Then it is sent to the voltage

regulator through which the required 5V dc is supplied to the circuit.

POWER SUPPLY

RF RECEIVER

LCD DISPLAY

MICRO-

CONTROLLER

AT89S52

RFID READER

RFID TAG

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Fig 3.3: A typical transformer

Working of the transformer:

When a voltage is put on an inductor, it will induce an electromagnetic field. This field

will induce in the second inductor a voltage. The ratio of voltage1 over voltage2 depends

on the ratio of rings in the coil.

Fig 3.4: Windings in the transformer

The transformer is based on two principles: First that an electric current can produce a

magnetic field (electromagnetism) and second that a changing magnetic field within a

coil of wire induces a voltage across the ends of the coil (electromagnetic induction).

Changing the current in the primary coil changes the magnetic flux that is developed.

The changing magnetic flux induces a voltage in the secondary coil.

Current passing through the primary coil creates a magnetic field. The primary and

secondary coils are wrapped around a core of very high magnetic permeability, such as

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iron, so that most of the magnetic flux passes through both the primary and secondary

coils. If a load is connected to the secondary winding, the load current and voltage will

be in the directions indicated, given the primary current and voltage in the directions

indicated (each will be alternating current in practice).

3.3 AT89S52 MICRO CONTROLLER

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller

with 8K bytes of in-system programmable Flash memory. The on-chip Flash allows the

program memory to be reprogrammed in-system or by a conventional nonvolatile

memory programmer.

3.3.1 BLOCK DIAGRAM OF AT89S52:

Fig 3.5: Block diagram of AT89S52

3.3.2 FEATURES:

8K bytes of Flash 256 bytes of RAM 32 I/O lines Watchdog timer two data pointers three 16-bit timer/counters

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a six-vector two-level interrupt architecture a full duplex serial port on-chip oscillator clock circuitryIn addition, the AT89S52 is designed with static logic for operation down to zero

frequency and supports two software selectable power saving modes. The Idle Mode

stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system

to continue functioning. The Power-down mode saves the RAM con-tents but freezes

the oscillator, disabling all other chip functions until the next interrupt or hardware reset.

3.3.3 PIN DIAGRAM AND ITS DESCRIPTION

Fig 3.6: Pin diagram of AT89S52

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DESCRIPTION:

VCC: Supply voltage.

GND: Ground.

Port 0: Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin

can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as

high-impedance inputs. Port 0 can also be configured to be the multiplexed low-order

address/data bus during accesses to external program and data memory. In this mode, P0

has internal pull-ups. Port 0 also receives the code bytes during Flash programming and

outputs the code bytes during program verification. External pull-ups are required

during program verification.

Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 1 output

buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are

pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that

are externally being pulled low will source current (IIL) because of the internal pull-ups.

In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count

input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as

shown in the following table. Port 1 also receives the low-order address bytes during

Flash programming and verification.

Port Pin Alternate Functions

P1.0 T2 (external count input to Timer/Counter

2), clock-out

P1.1 T2EX (Timer/Counter 2 capture/reload

trigger and direction control)

P1.5 MOSI (used for In-System Programming)

P1.6 MISO (used for In-System Programming)

P1.7 SCK (used for In-System Programming)

Table 3.1: Alternate functions of Port 1

Port 2: It is an 8-bit bidirectional I/O port with internal pull-ups. The Port 2 output



are externally being pulled low will source current (IIL) because of the internal pull-ups.

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Port 2 emits the high-order address byte during fetches from external program memory

and during accesses to external data memory that uses 16-bit addresses (MOVX @

DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s.

During accesses to external data memory that uses 8-bit addresses (MOVX @ RI), Port

2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-

order address bits and some control signals during Flash programming and verification.

Port 3: It is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output



are externally being pulled low will source current (IIL) because of the pull-ups. Port 3

receives some control signals for Flash programming and verification. Port 3 also serves

the functions of various special features of the AT89S52, as shown in the following

table.

Port Pin Alternate Functions

P3.0 RXD (serial input port)

P3.1 TXD (serial output port)

P3.2 INT0 (external interrupt 0)

P3.3 INT1 (external interrupt 1)

P3.4 T0 (timer 0 external input)

P3.5 T1 (timer 1 external input)

P3.6 WR (external data memory write strobe)

P3.7 RD (external data memory read strobe)

Table 3.2: Alternate functions of Port 3

RST: A high on this pin for two machine cycles while the oscillator is running resets

the device. This pin drives high for 98 oscillator periods after the Watchdog times out.

The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the

default state of bit DISRTO, the RESET HIGH out feature is enabled.

ALE/PROG: Address Latch Enable (ALE) is an output pulse for latching the low byte

of the address during accesses to external memory. This pin is also the program pulse

input (PROG) during Flash programming. In normal operation, ALE is emitted at aconstant rate of 1/6 the oscillator frequency and may be used for external timing or

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clocking purposes. Note, however, that one ALE pulse is skipped during each access to

external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR

location 8EH. With the bit set, ALE is active only during a MOVX or MOVC

instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no

effect if the microcontroller is in external execution mode.

PSEN: Program Store Enable (PSEN) is the read strobe to external program memory.

When the AT89S52 is executing code from external program memory, PSEN is

activated twice each machine cycle, except that two PSEN activations are skipped

during each access to external data memory.

EA/VPP: External Access Enable (EA) must be strapped to GND in order to enable the

device to fetch code from external program memory locations starting at 0000H up to

FFFFH. However, if lock bit 1 is programmed, EA will be internally latched on reset.

EA should be strapped to VCC for internal program executions. This pin also receives

the 12-volt programming enable voltage (VPP) during Flash programming.

XTAL1: Input to the inverting oscillator amplifier and input to the internal clock

operating circuit.

XTAL2: Output from the inverting oscillator amplifier.

3.3.4 MEMORY ORGANISATION:

MCS-51 devices have a separate address space for Program and Data Memory. Up to

64K bytes each of external Program and Data Memory can be addressed.

Program Memory

If the EA pin is connected to GND, all program fetches are directed to external memory.

On the AT89S52, if EA is connected to VCC, program fetches to addresses 0000H

through 1FFFH are directed to internal memory and fetches to addresses 2000H through

FFFFH are to external memory.

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Data Memory

The AT89S52 implements 256 bytes of on-chip RAM. The upper 128 bytes occupy a

parallel address space to the Special Function Registers. This means that the upper 128bytes have the same addresses as the SFR space but are physically separate from SFR

space. When an instruction accesses an internal location above address 7FH, the address

mode used in the instruction specifies whether the CPU accesses the upper 128 bytes of

RAM or the SFR space. Instructions which use direct addressing access the SFR space.

For example, the following direct addressing instruction accesses the SFR at location

0A0H (which is P2).

MOV 0A0H, #data

Instructions that use indirect addressing access the upper 128 bytes of RAM. For

example, the following indirect addressing instruction, where R0 contains 0A0H,

accesses the data byte at address 0A0H, rather than P2 (whose address is 0A0H).

MOV @R0, #data

Stack operations are examples of indirect addressing, so the upper 128 bytes of data

RAM are available as stack space.

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3.3.5 ARCHITECTURE OF AT89S52 MICROCONTROLLER:

Fig 3.7: Architecture of AT89S52 microcontroller

The AT89S52 has 4 different ports, each one having 8 Input/output lines providing a

total of 32 I/O lines. Those ports can be used to output DATA and orders do other

devices, or to read the state of a sensor, or a switch. Most of the ports of the 89S52 have

'dual function' meaning that they can be used for two different functions.

The first one is to perform input/output operations and the second one is used to

implement special features of the microcontroller like counting external pulses,

interrupting the execution of the program according to external events, performing serial

data transfer or connecting the chip to a computer to update the software. Each port has 8

pins, and will be treated from the software point of view as an 8-bit variable called

'register', each bit being connected to a different Input/output pin.

There are two different memory types: RAM and EEPROM. Shortly, RAM is used to

store variable during program execution, while the EEPROM memory is used to store the

program itself, that's why it is often referred to as the 'program memory'. It is clear that

the CPU (Central Processing Unit) is the heart of the micro controllers. It is the CPU that

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will Read the program from the FLASH memory and execute it by interacting with the

different peripherals.

3.4 COMPONENTS AND WORKING OF RFID

3.4.1 WORKING OF RFID

In every RFID system the transponder Tags contain information. This information can

be as little as a single binary bit, or be a large array of bits representing such things as

an identity code, personal medical information, or literally any type of information that

can be stored in digital binary.

Fig 3.8: RFID transreceiver that communicates with a passive Tag.

Passive tags have no power source of their own and instead derive power from the

incident electromagnetic field. Commonly the heart of each tag is a microchip. When

the Tag enters the generated RF field it is able to draw enough power from the field to

access its internal memory and transmit its stored information. When the transponder

Tag draws power in this way the resultant interaction of the RF fields causes the

voltage at the transceiver antenna to drop in value. This effect is utilized by the Tag to

communicate its information to the reader. The Tag is able to control the amount of

power drawn from the field and by doing so it can modulate the voltage sensed at the

Transceiver according to the bit pattern it wishes to transmit.

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3.4.2 COMPONENTS OF RFID

A basic RFID system consists of three components:

An antenna or coil A transceiver (with decoder) A transponder (RF tag) electronically programmed with unique information.

3.4.2.1ANTENNA

The antenna emits radio signals to activate the tag and read and write data to it. Antennas

are the conduits between the tag and the transceiver, which controls the system's data

acquisition and communication. Antennas are available in a variety of shapes and sizes;

they can be built into a door frame to receive tag data from persons or things passing

through the door, or mounted on an interstate tollbooth to monitor traffic passing by on a

freeway. The electromagnetic field produced by an antenna can be constantly present

when multiple tags are expected continually. If constant interrogation is not required, a

sensor device can activate the field.

Often the antenna is packaged with the transceiver and decoder to become a reader (a.k.a.

interrogator), which can be configured either as a handheld or a fixed-mount device. The

reader emits radio waves in ranges of anywhere from one inch to 100 feet or more,

depending upon its power output and the radio frequency used. When an RFID tag passes

through the electromagnetic zone, it detects the reader's activation signal. The reader

decodes the data encoded in the tag's integrated circuit (silicon chip) and the data is

passed to the host computer for processing.

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Fig3.9: Internal Structure of RFID tag

3.4.2.2 TAGS (Transponders)

An RFID tag is comprised of a microchip containing identifying information and an

antenna that transmits this data wirelessly to a reader. At its most basic, the chip will

contain a serialized identifier, or license plate number, that uniquely identifies that item,

similar to the way many bar codes are used today. A key difference, however is that

RFID tags have a higher data capacity than their bar code counterparts. This increases the

options for the type of information that can be encoded on the tag, including the

manufacturer, batch or lot number, weight, ownership, destination and history (such as

the temperature range to which an item has been exposed). In fact, an unlimited list of

other types of information can be stored on RFID tags, depending on application needs.

An RFID tag can be placed on individual items, cases or pallets for identification

purposes, as well as on fixed assets such as trailers, containers, totes, etc.

Tags come in a variety of types, with a variety of capabilities. Key variables include:

"Read-only" versus "read-write"

There are three options in terms of how data can be encoded on tags: (1) Read-only tags

contain data such as a serialized tracking number, which is pre-written onto them by the

tag manufacturer or distributor. These are generally the least expensive tags because theycannot have any additional information included as they move throughout the supply

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chain. Any updates to that information would have to be maintained in the application

software that tracks SKU movement and activity. (2) "Write once" tags enable a user to

write data to the tag one time in production or distribution processes. Again, this may

include a serial number, but perhaps other data such as a lot or batch number. (3) Full

"read-write" tags allow new data to be written to the tag as neededand even written

over the original data. Examples for the latter capability might include the time and date

of ownership transfer or updating the repair history of a fixed asset. While these are the

most costly of the three tag types and are not practical for tracking inexpensive items,

future standards for electronic product codes (EPC) appear to be headed in this direction.

Fig 3.10: RFID Tags

Data capacity: The amount of data storage on a tag can vary, ranging from 16 bits on the

low end to as much as several thousand bits on the high end. Greater the storage capacity,

the higher the price per tag.

Form factor: The tag and antenna structure can come in a variety of physical form

factors and can either be self-contained or embedded as part of a traditional label

structure (i.e., the tag is inside what looks like a regular bar code labelthis is termed a

'Smart Label') companies must choose the appropriate form factors for the tag very

carefully and should expect to use multiple form factors to suit the tagging needs of

different physical products and units of measure. For example, a pallet may have an

RFID tag fitted only to an area of protected placement on the pallet itself. On the other

hand, cartons on the pallet have RFID tags inside bar code labels that also provide

operators human-readable information and a back-up should the tag fail or pass through

non RFID-capable supply chain links.

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Passive versus active: Passive tags have no battery and "broadcast" their data only

when energized by a reader. That means they must be actively polled to send

information. "Active" tags are capable of broadcasting their data using their own battery

power. In general, this means that the read ranges are much greater for active tags than

they are for passive tagsperhaps a read range of 100 feet or more, versus 15 feet or less

for most passive tags. The extra capability and read ranges of active tags, however, come

with a cost; they are several times more expensive than passive tags. Today, active tags

are much more likely to be used for high-value items or fixed assets such as trailers,

where the cost is minimal compared to item value, and very long read ranges are

required. Most traditional supply chain applications, such as the RFID-based tracking

and compliance programs emerging in the consumer goods retail chain, will use the less

expensive passive tags.

Frequencies: Like all wireless communications, there are a variety of frequencies or

spectra through which RFID tags can communicate with readers. Again, there are trade-

offs among cost, performance and application requirements. For instance, low-frequency

tags are cheaper than ultra high-frequency (UHF) tags, use less power and are better able

to penetrate non-metallic substances. They are ideal for scanning objects with high water

content, such as fruit, at close range. UHF frequencies typically offer better range and

can transfer data faster. But they use more power and are less likely to pass through some

materials. UHF tags are typically best suited for use with or near wood, paper, cardboard

or clothing products. Compared to low-frequency tags, UHF tags might be better for

scanning boxes of goods as they pass through a bay door into a warehouse. While the tag

requirements for compliance mandates may be narrowly defined, it is likely that a variety

of tag types will be required to solve specific operational issues. You will want to work

with a company that is very knowledgeable in tag and reader technology to appropriately

identify the right mix of RFID technology for your environment and applications.

EPC Tags

EPC refers to "electronic product code," an emerging specification for RFID tags, readers

and business applications first developed at the Auto-ID Center at the Massachusetts

Institute of Technology. This organization has provided significant intellectual leadership

toward the use and application of RFID technology. EPC represents a specific approach

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to item identification, including an emerging standard for the tags themselves, including

both the data content of the tag and open wireless communication protocols. In a sense,

the EPC movement is combining the data standards embodied in certain bar code

specifications, such as the UPC or UCC-128 bar code standards, with the wireless data

communication standards that have been developed by ANSI and other groups.

3.4.2.3 TRANSRECEIVER

The RF transceiver is the source of the RF energy used to activate and power the passive

RFID tags. The RF transceiver may be enclosed in the same cabinet as the reader or it

may be a separate piece of equipment. When provided as a separate piece of equipment,

the transceiver is commonly referred to as an RF module. The RF transceiver controls

and modulates the radio frequencies that the antenna transmits and receives. The

transceiver filters and amplifies the backscatter signal from a passive RFID tag. An RFID

transceiver is a device that transmits radio waves to RFID tags and receives the radio

waves reflected or transmitted by the tags.

3.5 SERIAL COMMUNICATION:

Serial communication is a way enables different equipments to communicate with their

outside world. It is called serial because the data bits will be sent in a serial way over a

single line. A personal computer has a serial port known as communication port or COM

Port used to connect a modem for example or any other device, there could be more then

one COM Port in a PC. Serial ports are controlled by a special chip called UART

(Universal Asynchronous Receiver Transmitter). Different applications use different pins

on the serial port and this basically depend of the functions required. If you need to

connect your PC for example to some other device by serial port, then you have to read

instruction manual for that device to know how the pins on both sides must be connected

and the setting required.

Serial communication has some advantages over the parallel communication. One of the

advantages is transmission distance, serial link can send data to a remote device more far

then parallel link. Also the cable connection of serial link is simpler then parallel link and

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uses less number of wires. Serial link is used also for Infrared communication, now many

devices such as laptops & printers can communicate via inferred link.

There are two methods for serial communication, Synchronous & Asynchronous.

(A) Synchronous serial communication:

In Synchronous serial communication the receiver must know when to read the next bit

coming from the sender, this can be achieved by sharing a clock between sender and

receiver. In most forms of serial Synchronous communication, if there is no data

available at a given time to transmit, a fill character will be sent instead so that data is

always being transmitted. Synchronous communication is usually more efficient because

only data bits are transmitted between sender and receiver; however it will be more

costly because extra wiring and control circuits are required to share a clock signal

between the sender and receiver.

(B) Asynchronous serial communication:

Asynchronous transmission allows data to be transmitted without the sender having to

send a clock signal to the receiver. Instead, special bits will be added to each word in

order to synchronize the sending and receiving of the data.

When a word is given to the UART for Asynchronous transmissions, a bit called the

"Start Bit" is added to the beginning of each word that is to be transmitted. The Start Bit

is used to alert the receiver that a word of data is about to be sent, and to force the clock

in the receiver into synchronization with the clock in the transmitter.

After the Start Bit, the individual bits of the word of data are sent; each bit in the word is

transmitted for exactly the same amount of time as all of the other bits. When the entire

data word has been sent, the transmitter may add a Parity Bit that the transmitter

generates. The Parity Bit may be used by the receiver to perform simple error checking.

Then at least one Stop Bit is sent by the transmitter. If the Stop Bit does not appear when

it is supposed to, the UART considers the entire word to be garbled and will report a

Framing Error. The standard serial communications hardware in the PC does not support

Synchronous operations.

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3.6 RS-232

It is the traditional name for a series of standards for serial binary single ended data and

control signals connecting between aDTE(Data Terminal Equipment) and aDCE(Datacircuit-terminating Equipment). It is commonly used in computer serial ports. The

standard defines the electrical characteristics and timing of signals, the meaning of

signals, and the physical size and pin out of connectors.

An RS-232 port was once a standard feature of a personal computer for connections to

modems, printers, mice, data storage, un-interruptible power supplies, and other

peripheral devices. However, the limited transmission speed, relatively large voltage

swing, and large standard connectors motivated development of the universal serial bus

which has displaced RS-232 from most of its peripheral interface roles. Many modern

personal computers have no RS-232 ports and must use an external converter to connect

to older peripherals. Some RS-232 devices are still found, especially in industrial

machines or scientific instruments.

3.6.1 PIN DIAGRAM AND ITS FUNCTIONS:

Fig 3.11: 9 pin Male D-Type plug Connector

Fig 3.12: 9 pin Female D-Type plug Connector

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PIN NUMBER PIN SYMBOL FUNCTION

1 DCD Data Carrier detect (This

line is active when modem

detects a carrier

2 TD Transmit data(Serial Data

Output)

3 RD Receive data(Serial Data

Input)

4 DTR Data Terminal Ready

5 SG Signal Ground

6 DSR Data Ready State(UARTestablishes a link)

7 RTS Request to send

(acknowledge to modem

that UART is ready to

exchange data)

8 CTS Clear to send (Modem is

ready to exchange data)

9 RI Ring Indicator (Becomesactive when modem detects

ringing signal from PSTN )

Table3.3: Functions of the pins in RS-232

3.6.2 LIMITATIONS:

The large voltage swings and requirement for positive and negative suppliesincreases power consumption of the interface and complicates power supply design.

The voltage swing requirement also limits the upper speed of a compatible interface.

Single-ended signaling referred to a common signal ground limits the noiseimmunity and transmission distance.

Multi-drop connection among more than two devices is not defined. While multi-drop "work-around" has been devised, they have limitations in speed and

compatibility.

Asymmetrical definitions of the two ends of the link make the assignment of the roleof a newly developed device problematic; the designer must decide on either a DTE-

like or DCE-like interface and which connector pin assignments to use.

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The handshaking and control lines of the interface are intended for the setup andtakedown of a dial-up communication circuit; in particular, the use of handshake

lines for flow control is not reliably implemented in many devices.

No method is specified for sending power to a device. While a small amount ofcurrent can be extracted from the DTR and RTS lines, this is only suitable for low

power devices such as mice.

The 25-way connector recommended in the standard is large compared to currentpractice.

3.7 LIQUID CRYSTAL DISPLAY (LCD):

Liquid Crystal Display is a type of display which used in digital watches and many

portable computers. LCD displays utilize two sheets of polarizing material with a liquid

crystal solution between them. An electric current passed through the liquid causes the

crystals to align so that light cannot pass through them. Each crystal, therefore, is like a

shutter, either allowing light to pass through or blocking the light.

The liquid crystals can be manipulated through an applied electric voltage

so that light is allowed to pass or is blocked. By carefully controlling where and what

wavelength (color) of light is allowed to pass, the LCD monitor is able to display images.

A back light provides LCD monitors brightness.

Other advances have allowed LCDs to greatly reduce liquid crystal cell

response times. Response time is basically the amount of time that it takes for a pixel to

change colors. In reality response time is the amount of time it takes a liquid crystal

cell to go from being active to inactive.

They make complicated equipment easier to operate. LCDs come in

many shapes and sizes but the most common is the 16 character x 4 line (16x4) display

with no backlight. It requires only 11 connectionseight bits for data (which can be

reduced to four if necessary) and three control lines (we have only used two here). It runs

off a 5V DC supply and only needs about 1mA of current. The display contrast can be

varied by changing the voltage into pin 3 of the display.

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Fig 3.13: Front and Back side view of LCD

3.7.1 FEATURES OF LCD

1. 16 Characters x 2 Lines

2. 5x7 Dot Matrix Character + Cursor

3. HD44780 Equivalent LCD Controller / driver Built-in

4. 4-bit or 8-bit MPU interface

5. Standard Type

6. Works with almost any Microcontroller

3.7.2 PIN CONFIGURATION OF LCD:

Pin diagram consists of VSS, VDD and VEE. 8-bit data lines are

connected from pin 7 to pin 14. Out of these 8 data lines only 4 data lines are used in this

session.

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Fig 3.14: Pin configuration of LCD

First pin is connected to ground. 5V of supply is provided at the VCC. Mainly LCD

consists of Display Unit, DRAM and Controller. Controller controls the actions

performed. VEE is used for controlling LCD contrast. Three control lines are EN, RS and

R/W.

3.7.3 LCD PIN DESCRIPTIONS

VCC, VSS and VEE: While VCC and VSS provide +5V and ground respectively, VEE

is used for controlling LCD contrast.

PIN SYMBOL I/O DESCRIPTION

1 VSS -- Ground

2 VCC -- +5V power supply

3 VEE -- Power supply to control contrast

4 RS IRS=0 to select command register,

RS=1 to select data register

5 R/W I R/W=0 for write, R/W=1 for read

6 EN I/O Enable

7 DB0 I/O The 8-bit data bus

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Table 3.4: Pin description of LCD

EN: The ENline is called Enable. This control line is used to tell the LCD that you are

sending it data. To send data to the LCD, your program should first set this line high (1)

and then set the other two control lines and/or put data on the data bus. When the other

lines are completely ready, bring EN low (0) again. The 1-0 transition tells the 44780 to

take the data currently found on the other control lines and on the data bus and to treat it

as a command.

RS: The RSline is the Register Select line. When RS is low (0), the data is to be

treated as a command or special instruction (such as clear screen, position cursor etc).

When RS is high (1), the data that is sent is a text data which should be displayed on the

screen. For example, to display the letter T on the screen you would set RS high.

RW: The RWline is the Read/Write control line. When RW is low (0), the

information on the data bus is being written to the LCD. When RW is high (1), theprogram is effectively querying (or reading) the LCD. Only one instruction (Get LCD

status) is a read command. All others are write commands, so RW will almost be low.

Finally, the data bus consists of 4 or 8 lines (depending on the mode of

operation selected by the user). In the case of an 8-bit data bus, the lines are referred to as

DB0, DB1, DB2, DB3, DB4, DB5, DB6 and DB7. The ASCII code to be displayed is

eight bits long and is sent to the LCD either four or eight bits at a time.

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If 4-bit mode is used, two nibbles of data (sent high four bits and then

low four bits with an E clock pulse with each nibble)are sent to make up a full eight bit

transfer.

The E Clock is used to initiate the data transfer within the LCD.

Deciding how to send the data to the LCD is most critical decision to be made for an

LCD interface application.

8-bit mode is best used when speed is required in an application and at

least ten I/O pins are available. The R/S bit is used to select whether data or an

instruction is being transferred between the microcontroller and the LCD. If the Bit is set,

then the byte at the current LCD Cursor position can be written. When the bit is reset,

either an instruction is being sent to the LCD or the execution status of the last

instruction is read back.

3.7.4 ADVANTAGES OF LCD

LCD interfacing with microcontroller is a real-world application. In recent

years the LCD is finding widespread use replacing LEDs (seven segment LEDs or

other multi segment LEDs). This is due to following reasons:

1. The declining prices of LCDs are useful to use these LCDs for displayingpurpose.

2. The ability to display numbers, characters and graphics. This is in contrast toLEDs, which are limited to numbers and a few characters. An intelligent LCD

displays two lines, 20 characters per line, which is interfaced to the

microcontroller.

3. Incorporation of a refreshing controller into the LCD, thereby relieving the CPUto keep displaying the data. Before data will be refreshed or clearing inbox as

soon as the supply is on or when circuit is on.

4. Ease of programming for characters and graphics.

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CHAPTER 4

SOFTWARE DEVELOPMENT TOOL

4.1 KEIL SOFTWARE

Keil C51 is the industry-standard tool chain for all 8051-compatible devices, it

supports classic 8051, Dallas 390, NXP MX, extended 8051 variants, and C251 devices.

The Vision IDE/Debugger integrates complete device simulation, interfaces too many

target debug adapters, and provides various monitor debug solutions.

The Keil 8051 Development Tools are designed to solve the complex problems faced by

embedded software developers.

When starting a new project, simply select the microcontroller you use from theDevice Database and the Vision IDE sets all compiler, assembler, linker, and

memory options for you.

Numerous example programs are included to help you get started with the mostpopular embedded 8051 devices.

The Keil Vision Debugger accurately simulates on-chip peripherals (IC, CAN,UART, SPI, Interrupts, I/O Ports, A/D Converter, D/A Converter, and PWM

Modules) of your 8051 device. Simulation helps you understand hardware

configurations and avoids time wasted on setup problems. Additionally, with

simulation, you can write and test applications before target hardware is

available.

When you are ready to begin testing your software application with targethardware, use the MON51, MON390, MONADI, or FlashMON51 Target

Monitors, the ISD51 In-System Debugger, or the ULINK USB-JTAG Adapter to

download and test program code on your target system.

4.2 OVERVIEWViewing Code & Data: The Vision Debugger provides a number of ways to

display variables and program objects.

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Executing Code: Vision offers several ways to control and manipulate program

execution.

Advanced Analysis Tools: Advanced analysis tools are available to help you test

and debug your embedded applications.

Simulation: Simulation capabilities make it possible to test your target system

without target hardware.

Target Debugging: Target debug drivers allow you to test programs running on

target hardware.

4.3VIEWING DATAThe Vision Debugger offers a number of different views into the code and data that

comprise your target application.

Source Code Window: It displays high-level language and assembly program source

code.

Disassembly Window: It shows mixed high-level language and assembly code.

System Registers: The Registers Tab of the Project Workspace shows system registers.

Symbol Window: It heir archly displays program symbols in your application.

Output Window: It displays the output of various debugger commands.

Memory Window: It displays up to four regions of code or data memory.

Watch Window: It displays local variables, user-defined watch expression lists, and the

call stack.

System Viewer Window: It provides detailed status information about device peripheralregister contents while the processor is running.

4.4 EXECUTING CODE

Vision provides run controls to start, stop, and step through your embedded application.

You may use breakpoints and trace memory to conditionally halt program execution and

review previously executed program code.

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Reset:

It is possible to debug reset conditions using the Vision Simulator.

Run/Stop:

Buttons and Commands make starting and stopping program execution is easy.

Single-Stepping:

Vision supports various methods of single-stepping through your target program.

Execution trace:

Execution trace information for each executed instruction is stored by Vision.

Breakpoints:

Both simple and complex breakpoints are supported by the Vision Debugger.

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CHAPTER 5

RESULT ANALYSIS

The circuit looks like this before it is switched ON.

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When initially a circuit is switched on a message RFID TRANSMITTER is displayed

on the LCD of the transmitter and RFID RECEIVER is displayed on the receiver.

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When an RFID tag is bought into the range of RFID reader then the message already

feeded into the program is displayed on the LCD of the transmitter. On the other handthis detail is passed on over to the receiver which in turn displays the same on its LCD.

CONCLUSION

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This technology is an upcoming technology and after a few years it is believed to replace

all the existing used today. The main reason for it taking so long to rise in the market iscost. Unfortunately, the price of RFID will not come down until its demand increases and

its demand in the market will not increase despite its advantages unless its price

decreases. One of the best about RFID is that it is being developed to be ECO-

FRIENDLY. Eco20 low power RFID are significantly more efficient because they

consume 60% less energy when compared to most competitors comparable products in

the market. Low power consumption in turn cascades beneficially across the required

power supplies and utility equipment connected to the entire end user system .Low power

consumption means less power supplies, peripheral equipment, communication

converters etc.

ADVANTAGES:

Automated operation Low Power consumption Security.

As our project is an advanced method of security system, it has few disadvantages also.

DISADVANTAGES:

If the number of RFID readers is increased, the cost and complexity of the projectincreases.

Without GUI mode of operation, the working status of RFID transceiver isunpredictable.

Security becomes unreliable, if any RFID tag is lost. Fault finding between the individual RFID modules is complex.

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FUTURE SCOPE

Some vendors have been combining RFID tags with sensors of different kinds. This

would allow the tag to report not simply the same information over and over, but

identifying information along with current data picked up by the sensor. For example, an

RFID tag attached to a leg of lamb could report on the temperature readings of the past

24 hours, to ensure that the meat was properly kept cool.

Over time, the proportion of "scan-it-yourself" aisles in retail stores will increase.

Eventually, we may wind up with stores that have mostly "scan-it-yourself" aisles and

only a few checkout stations for people who are disabled or unwilling.

Efforts are being made to implant them into human beings. RFID devices that are

intended to be implanted inside a living body (like an animal or human being) havespecial requirements. They need to be encased in a special kind of casing that will not

irritate or react with the living tissues that they are inserted into. The casing must also be

transparent to the scanning radio-frequency beam that activates the chip. Some RFID

vendors have created biocompatible glass for use in these applications. Because the

radio-frequency waves that activate the microchip containing the identification number

are only useful within a few feet (or less), the RFID chip is typically inserted very close

to the surface of the skin.

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The placement of the device is usually done with a hyperdermic-type needle. This

method of insertion also dictates the shape and size of the device; implantable RFID

devices are typically the size and diameter of a grain of rice. For dogs, the device is

usually implanted between the shoulder blades.

Going by this scenario and its increasing demand in high level applications it is very

much clear that it will not take much time for RFID to take over the world.

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BIBLIOGRAPHY

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