Parallax RFID board

From HacDC Wiki

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Setting the parallax RFID up is painfully simple. Just hook it up to a serial port at 2400,8,N,1 and you're off.

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It's a simple device -- basically an RFID chip and a PIC used to interface with serial. The RFID chip EM4095 is designed for low-frequency, amplitude modulated transponders.

There's not much of an obvious way to hack into the thing because most all of the functionality (frequency generation, signal detection) is in the EM4095. I tried tapping the Demod Out pin to see if I could get any info that the PIC wasn't letting pass through.

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I tried a variety of cards on the thing. Mostly-predictably, only the low-freq cards that it came with gave out anything that made sense.

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Using one of the supplied cards spits out what a reasonably low-frequency data stream.

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The only other card that got any response was the Zipcard, which sync'ed up with the RFID at 133kHz, but spat data that looks like the Zipcard's running at a much higher frequency -- probably a multiple of 133?

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So basically, the parallax unit seems to be easy and reliable with its cards, but sadly not too hackable/expandable.