Phidgets RFID

What Can the Phidget RFID Do?

Phidgets RFID Kit is a USB connected RFID reader/device for Windows and Mac operating systems. It is useful for prototyping, home automation, museum exhibit design, marketing and kiosk/terminal applications. Industry applications of RFID include the pharmaceutical industry, supply chain management, libraries and media management, garment/grocery tagging, airline industry and pacel/postal agencies.

RFID is a technology that enables wireless data capture and transaction processing. There are two main areas of application, defined broadly as proximity (short range) and vicinity (long range). Long range or vicinity applications can generally be described as track and trace applications, but the technology provides additional functionality and benefits for product authentication – i.e. Tracking student attendance and location within a high school. Short range or proximity applications are typically access control applications – i.e. Checking a book out at a library.

RFID tags can be attached to things you have lots off and, when read, tell you where that particular thing is. The tag does not have to be visible to be read. RFID tags come in all shapes and sizes; some as large as a business card, others as small as a pill and a few as thin as a sheet of tissue paper. No other power is required; the USB bus supplies all the power. This particular RFID device connects via the USB cable and a web services terminal. It allows you to read from any number of RFID form factors using a 125kHz Read-only protocol. A unique feature the Phidgets RFID device has is the ability to utilize Flash MX/8 to connect and read RFID tagged devices.

With absolutely no hardware knowledge or experience you can include Radio Frequency Identification (RFID) tags into your projects. It is just a matter of plugging your reader into the USB port on your computer. After that, you can use the simple to program Phidgets software libraries to access the reader.
They can read any of the types of RFID tag available from Phidgets that are brought within 3 inches of the reader. When a RFID tag is read, the board returns the unique number contained in the RFID tag.

“Black Magic”
(aka, as long as it works I don’t care to know how…)

The PhidgetRFID board can be controlled from Windows, Linux, and Mac OS X. High-level programming interfaces are available for Visual Basic, C, C++, Flash, .NET, Java, LabVIEW, etc. The PhidgetRFID reads RFID tags that use the EM Marrin protocol, EM4102. This is a 125kHz read-only protocol. Other styles of tags will work if they use the EM4102 protocol. The reader returns a 40-bit read-only unique ID number contained in the tag. There is no capability for anti-collision or read/write. If two tags are in the read field at the same time, the reader will not read either tag. If two readers are brought to close together, while enabled, neither will function. However, an individual reader can be disabled from software, allowing a collection of PhidgetRFID boards to be polled sequentially.

Expansion

The PhidgetRFID has four outputs. Two outputs are available for the user and two outputs are used on the board itself.

Output 0 is a + 5 V source from the USB bus (through a P Channel MOSFET with less then one ohm impedance). This can be used to switch any TTL device, or it can be used to drive a relay such as the Aromat JS1-5V. When driving a relay it is important to use a fast clamping diode across the drive pins of the relay, otherwise the PhidgetRFID board can be damaged. A relay is useful when you want a low voltage device to switch on a high voltage device.

Output 1 is an LED drive output, with 5 V at 20 mA (250 ohm CMOS output). It can also be used to light up an external light or power a low voltage motor.

Output 2 controls an on board surface mounted LED using a button, switch or dial.

Output 3 controls the RF portion of the reader and allows the reader to be enabled or disabled. This feature allows a collection of readers to be polled sequentially without them interfering with each other.

Phidgets RFID Reader Caveats:
– The RFID Reader and Tags are READ ONLY.

– The read range on the reader is 4 inches or less depending upon the tag you are using. The estimated read range are listed for each tag in it’s description in the catalogue.

– The reader cannot read multiple tags in the field at the same time.

– Readers placed too close to each other will cause them to fail in operation. Allow at least a meter of distance between readers. For closer placement you must make use of the reader on/off feature to access one reader at a time.

– The reader antenna cannot be detached from the RFID reader or altered in any way.

What’s next!?

Phidgets, Inc.
http://www.phidgetsusa.com
http://www.phidgets.com

Projects and Examples
http://www.phidgets.com/modules.php?op=modload&name=Web_Links&file=index

Interview with RFID Implanter
http://www.makezine.com/blog/archive/2005/04/interview_with_1.html

Artists Burnish RFID’s Image
http://www.wired.com/news/technology/0,70135-0.html

RFID Toys
11 Cool Projects for Home, Office and Entertainment
(ExtremeTech) (Paperback) Available at Amazon.com
~$16.50
http://www.rfidtoys.net