RF-ID Card Reader

Motivation:

• As we were discussing about the automated security cum attendance system using bio-metric system, or tagging the products of a retail store, or using something for security of goods, or scanning any item in a non-line of sight, the only thing which came in our mind was RFID.

• This gave us an idea that RFID can be used in a vast field of counting/security/tagging/attendance system.

Aim --

• To design an RFID system which can be integrated with computer to fetch the data automatically, basically can be used as attendance system, door opening, automated electrical system, Security of the bigger land.

What is RF-ID ?

• It stands for Radio-frequency-identification.

• RFID is also called dedicated short range communication (DSRC).

• It is a technology that uses communication through the use of radio waves to transfer data between a reader and an electronic tag attached to an object for the purpose of identification and tracking.

• Radio-frequency identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders.

•RFID makes it possible to give each product in a grocery store its own unique identifying number, to provide assets, people, work in process, medical devices etc. all with individual unique identifiers - like the license plate on a car but for every item in the world.

RFID Card reader

Basic Block Diagram

ATmega8

Tx

Rx DATA PIN

PORT 2

RFID TAG

Explanation for Block diagram• RFID Tags: 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 .

• Transceiver: Used for transmitting and receiving high frequency signals between tags and readers. Transceiver is accompanied with a duplexer used to isolate transmitting signals from receiving signals .

• Integrated circuit: IC used here is ATmega8,

• The device supports throughput of 16 MIPS at 16 MHz and operates between 2.7-5.5 volts.

• Display system: LCD screen is used as a display device used to the card data which can be in binary form or in user friendly language.

• It is a flat panel display, which uses light emitting diodes as a video display. An LCD panel is a small display, or a component of a larger display.

• RFID Reader: Used to read and store the data of RFID Tags.

The description• ATmega8:• The low-power Atmel 8-bit AVR RISC based microcontroller

combines 8kb of programmable flash memory, 1KB of SRAM, 512K EEPROM, and 8 channel 10-bit A/D convertor. The device supports throughput of 16 MIPS at 16 MHz and operates between 2.7-5.5 volts.

•• Key parameters:•• Flash (Kbytes): 8•• Pin Count: 28•• Max. Operating frequency: 16MHz•• CPU: 8-bit AVR

Frequency Variation• There are basically 2 types of systems that can be

used-active and passive.

• Hence the operating frequency can be varied in a wide range.

• It can be from 120 kHz upto an extent of 10 GHz i.e. Micro wave Range.

• The advantage of using it in between 3-10 GHz is that it can be used with the mobile tower that are already established.

• Our proto-type project works on 16 MHz freq.

Tags

• An RFID tag is comprised of a microchip containing identifying information and an antenna that transmits this data wirelessly to a reader.

• Tags come in a variety of types, with a variety of capabilities.

• 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.

• MCRF450.

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 .These are generally the least expensive tags because they cannot have any additional information included as they move throughout the supply chain.

• (2) "Write once" tags enable a user to write data to the tag one time in production or distribution processes. 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 needed—and even written over the original data.

Classification Based on Mobility.

Fixed RFID Mobile RFID

• If the reader reads tags in a stationary position, it is called fixed RFID.

• These fixed readers are set up specific interrogation zones and create a "bubble" of RF energy that can be tightly controlled if the physics is well engineered.

• This allows a very definitive reading area for when tags go in and out of the interrogation zone.

• If the reader is mobile when the reader reads tags, it is called mobile RFID.

• Mobile readers include hand held, carts and vehicle mounted RFID readers from manufacturers such as Motorola, Intermec.

• This does not allows a very definitive reading area as reader is mobile.

Passive – Not using any battery power, having very low range and frequency of 13.56 megahertz.

Active - with an on-board battery that always broadcasts or beacons its signal, having very high range and frequency between 125 to 134 kilohertz.

Passive Active

Classification based on types.

Active RFID Passive RFID

Tag Power Source Internal to tag Energy transferred using RF from reader

Tag Battery Yes No

Availability of power Continuous Only in field of reader

Required signal strength to Tag

Very Low Very High

Range Up to 100m Up to 3-5m, usually less

Multi-tag reading 1000’s of tags recognized – up to 100mph

Few hundred within 3m of reader

Data Storage Up to 128Kb read/write

128 bytes of read/write

Classification of RFID Card Reader

Circuit Diagram:

Snap shot

Working of RFID sytem:

• Reader produces an electromagnetic zone

• Tag enters it, and electrical coupling takes place

• The tag modulates the field produced by the reader by changing the electrical loading the tag represents.

• By switching between lower and higher relative loads, the tag produces a change that the reader can detect.

Costing :

Band Range Apprx. Cost

120-150 kHz 10 cm Rs 50

13.56 MHz 1 m Rs 25-30

433 MHz 1-100 m Rs 250-300

868-870 MHz902-928 MHz UHF

1-2 m Rs 5-10

2450 MHz-5800 MHz 1-2 m Rs 1200-1500

3.1 Ghz-10 GHz (MW) 1-200 m Rs 250-300

Talking about the cost:

• Prices have dropped to a low range of 1 to 10 cents though active and long-range tags are still expensive.

• With increasing use, the production costs and hence prices will drop.

• Here we can see that the graph of the cost decreases with respect to time.

• It means that maybe it would look like we have to pay a good amount of price to purchase RF-ID’s but as we see the time-line graph the value of it increases with time.

The Advantages of RFID Over Bar Coding:

• No "line of sight" requirements.

• More automated reading.

• Improved read rates.

• Greater data capacity.

• Write capabilities.

Issues/Concerns.• Cost of RFID technology.

• Active RFID life-2 to 4 years.

• Privacy concerns-surreptitious consumer surveillance.

• Extreme weather.

• Security concerns-illicit tracking of RFID tags.

• Global standardization.

• Environmental concern-recycling.

• RFID systems are vulnerable to virus.

•Used in enterprise supply chain management to improve the efficiency of inventory tracking and management.

•The Healthcare industry

•Electronic Vehicle Registration

•Animal identification

•Race timing

•Libraries

•Passports :e-passports

•Museums

RF-ID applications.

• The largest deployment of active RFID is the US Department of Defence use of Savi active tags on every one of its more than a million shipping containers that travel outside of the continental United States.

• This is the way in which a tag can be attached to any vehicle or container and can be used for security purpose.

The live example :

Prepared by:-

Harsha Gupta

Anurag Kapse