small tags for playing cards

[nitrous]

Hi there,

I see that you've created an RFID tagged playing card deck but what I was looking for was a tag that was small enough to implant into the cards that would be undetectible. Not to worry, I'm looking at this for a magic prop not a gambling scam! :)

Further, I'd like to be able to 'read' the tag and transmit the information to an LCD display (like a small pocket pager) within 10 meters or so of the reader assembly.

It would be nice to be able to read more than one tag at a time but absolutely necessary.

Any suggestions on type of reader that will read v small (in particular, thin) RFID tags and that could easily be transmitted to a small LCD message display?

Thanks,
Doug

[Dave]

Well, we sell the reader and an LCD module, but they're both tethered to a PC via USB. We looked into having the playing cards made with the RFID transponder built in, but in the end the time/money/hassle caused us to shelve the project in favor of a simpler, albeit less pretty, solution.

[nitrous]

Hi Dave,
Thanks for the response.
The fact is, playing cards can be split quite easily. This is usually to insert magnetic shim stock for certain effects. There is a company that has made such a system but the price is prohibitively high.
Thanks again,
Doug Gourlay

[dvmorris]

is there a way to tell which way a card is oriented with these rfid tags? By that I mean either whether it's face up or face down, and possibly even whether it's turned sideways or not.

Just curious, thanks for the help,
dave

[Alex]

Nope, sorry:( Good idea though! Hopefully some RFID company will design an RFID card with a gyro attachment option:D

[dvmorris]

so there could potentially be a way to have some other device dynamically set a flag on the rfid tag that says "isUpsideDown" or something?

i'm also wondering if there might be a way to track the position of a card on a mat or table if it had a passive tag in it. or would it be possible to use some triangulation technique with a tag in a card that didn't have a battery, but the current was induced by proximity to the mat... or would a better solution be to use a grid of readers under the mat, and just detect proximity to specific readers on the grid in order to display the contents of the mat on a digital screen. I actually found a patent from the european patent office entitled:

Method and Apparatus for televising a card game

and it talks about using rfid's in the cards: http://www.ends170.com/rfid_cards.rtf (text of the patent)

Anyways, I'm kind of a beginner with this RFID stuff. Thanks for your help,

dave

[Matt]

Hey Dave,

I'm going to be a big jerk and squash all your wish list items with my answer unfortunately.

RFID doesn't work in a way that can be used very well for positioning or orientation. RFID is a radio technology so think of it like a radio station and the radio in your living room. It's meant for storing a small bit of information and having a wireless source read from it. Like swiping a card in front of a reader. In essence it's a wireless barcode.

A grid of readers under a mat would all interfere with each other and do a poor job of locating positioning of items in close proximity. Such a device could be built in theory, but you are talking many thousands of dollars and a lot of expertise.

Sorry to be a buzz kill!

[dvmorris]

oh no worries i was just curious. I heard some people talking about an idea like that and it struck me as a little far-fetched...

[Alex]

I should clarify something that Matt stated:

RFID doesn't work in a way that can be used very well for positioning or orientation.I believe what Matt meant was that RFID won't work well for positioning in the way that you want to use it, using the products that we carry. You can detect positioning using RFID but I believe the only way to do so is to use Active RFID and triangulation. I have no specifics on this and it is way over my own head, but I have heard that it is possible.

Here's a link to a thread on Amal's (the author of RFID Toys (http://www.trossenrobotics.com/store/p/3607-RFID-Toys.aspx)) forum on RFID location tracking:

http://www.rfidtoys.net/forum/forum_posts.asp?TID=317&KW=triangulation