RFID in Indoor Location Sensing

Sucharitha SaibabaDivya Gopinathan

OBJECTIVE OF THE PROJECT

• To understand the working of RFID system.

• Program the RFID module using PSoC Designer software.

• To read and write data to the tags.

• To distinguish between multiple tags when simultaneously present in the field.

• To demonstrate a practical application of the RFID technology like a small scale Library Management system.

•RRadio FFrequency IdIdentification

•The only truly automatic AIDC technology

• Provides non-contact, non-line-of-sight operation

• Can be read-only, WORM (write once, read

many) or read/write

• Very difficult to counterfeit

• Capable of working in harsh environments

• Highly capable and proven technology for a wide

range of applications

What is RFID?

What Constitutes an RFID System?What Constitutes an RFID System?

• One or more RF tags

• Two or more antennas

• One or more interrogators

• One or more host computers

• Appropriate software

How Does RFID Work?

Reader Antenna

Reader broadcasts signal through antenna

Transponder

Transponder receives signal

Computer System

Reader sends info/data to computer system for logging and processing

Transponder is charged with enough energy to send back an identifying response

RFID Tag AttributesActive RFID Passive RFID

Tag Power Source Internal to tag Energy transferred using RF from

reader

Tag Battery Yes No

Required signal strength

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 128 Kb or read/ write & search

128 bytes of read/write

RFID Technical Design Considerations

– Operating Frequency• Available Frequency Bands• RF Signal Propagation (range, reflections, and material transmittance) • Interference

– Communication Signal• Interrogation Signal with request commands and control• Response Signal with unique identification and data

– Tag Design• Passive or Active Power• Antenna Design and Performance• Integrated Circuit Design

– Reader and Reader Antenna

– Networking Requirements

How far? How fast? ….....

RFID Programmer SM2005-B5

Main Components of the Project

• Cypress PSoC (programmable System-on-Chip) microcontroller.

• This microcontroller comes programmed with a Manchester RF 32/64 signal demodulator and decoder.

• The ChipModule has nine general purpose IO pins and about 4KB of flash memory that can be filled with custom built code.

• The custom code was written using PSOC Designer.

• Loading code is done through RS232C serial interface.

SMRFID GUI

Programming the Microcontroller

Objectives Achieved

• The communication is established between the

microcontroller on the chip module and PC.

• The individual tags are written into and read.

• Distinguish each tag from one another when multiple tags are present in the RF field.

Future Scope

• How this idea can be extended to a real time location system?

• The RFID readers can be embedded into the environment and the RFID tags carried by each user inform the system of the current location of that user.

• RFID tags are embedded into the environment while users carry RFID readers.

References

• www.fiatech.org/Presentations/texasinstruments

• www.sonmicro.com

• wwwx.cs.unc.edu/~sparkst/mobile/rfid/RFID

• www.uhisrc.com/FTB/RFID/RFIDsep03

• Blewett,Amin,et al.,”A Simple RF System for Asset Tracking Within Buildings”, IEE,1999

Thank you!Questions/Comments/Discussion