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How do I disable an RFID tag??? ( is it possible to disable the tags we have?) — Parallax Forums

How do I disable an RFID tag??? ( is it possible to disable the tags we have?)

raynel1raynel1 Posts: 4
edited 2006-02-23 16:50 in General Discussion
We purchased the 50 mm Round Tag Stock#: 28142 Category: Accessories-RF... and we are trying to build a mini EMP pulse generator out of a disposable camera - to send an EMP through a copper coil and "Kill" the RFID tags once they are purchased at our fictional cash register... the problem is: we are not sure how much current is needed to disable/kill these tags- or if it is even possible to do so. One of my group members suggested that i write on this forum and ask you guys for any suggestions/info. We have a javelin microcontroller, a Grand Idea Studio RFID Reader Module -Stock#: 28140, and the 50 mm Round Tags. Are we able to send a "code" to disable these tags using our Reader?? ( we have read that it is possible to do so with other models )??? please reply with any suggestions... Thanx.

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-23 01:26
    In theory you could generate a high energy pulse.· The thing is that the tags are tuned to a specific frequency so the most energy will be picked up around that frequency.· A high enough emission at that frequency could in theory destroy the tags, however it could be dangerous and in violation of FCC law.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-23 01:33
    Can you not just remove the tags at the register?· Is the merchandise sensitive to EMP?· Also, is this a Javelin-related product?

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • raynel1raynel1 Posts: 4
    edited 2006-02-23 01:47
    are these tags programmable??? are we able to disable them using code from the javelin microcontroller???
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-23 02:29
    They're not programmable...I thought you were trying to disable them permanently???

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2006-02-23 03:23
    Can you just ignore them in software?

    Read them with a second RFID reader at the register as if you are "Nuking" them with an EMP,
    then the reader at the door.... hopefully linked to the cash register will still read the RFID but
    will know to ignore it.

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • John R.John R. Posts: 1,376
    edited 2006-02-23 16:32
    Reading between the lines, I'm guessing that the concept of the project is to demonstrate a "friendly" RFID tag for use in retail. Use the RFID tag for inventory tracking, but then once the item is run through the cash register, disable the tag permanently so that the purchaser can be free of fear from prying antennas.

    If not an EMP, could you set up a layer of foil behind the tag, and use a large static charge (like from a van-de-Graff generator or Telsa coil? Kind of "zap" the tag into oblivion.

    This might also have some FCC and/or safety implications.

    A more vialble solution might be a different tag that is "writeable". This could then have both a "serial number" and the UPC code writen to it, and then upon read by the cash register be "blanked". This could also allow for tag "re-activiation" in the event of a return.

    I don't remember for sure, but I thought you could get tags on this frequency that were 'writeable'. You would be able to read these with the Parallax reader, but you;d need something different to write back (and/or erase) them.

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    John R.

    8 + 8 = 10
  • ktekxktekx Posts: 71
    edited 2006-02-23 16:50
    Have you checked this link out? events.ccc.de/congress/2005/wiki/RFID-Zapper(EN)

    It appears that a 1mm thick coil of wire loaded with 100v's from a common camera flash cap was able to disable the 13.56mhz RFID from a short range being just next to it. You can probably disable other frequencies tags by playing with the numbers. That could probably be safe since the range is so short and less likely to damage stuff around nearby, but FCC safety implications will still need to be looked at.
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