At 03:11 PM 4/8/2004 -0400, Kevin Vandermaarel wrote:

>Has anyone ever interfaced a Magentic Swipe Card reader with a PIC?  If so, what do you recommend for the type of swipe card and PIC?  Where might I find some sample schematics and code for this type of configuration?

Not a PIC, but it really doesn't matter.

Typically, on a decoded reader, you get from one, to three tracks, plus a card load signal.  Each track has clock and data.

You can pretty much ignore the card load signal, and just use interrupts on the clock pins, sampling the data when the ints happen. You can look up the ISO standards on how large a buffer you'll need.  The word lengths are short, track 2 is 5 bit, but you can add a constant to it to convert it directly into ascii.

Each track has various sanity checks, start and stop flags, which you'll find in the ISO docs.


If you're doing it with a raw head signal, then you'll need to decode the F-2F encoding, which is a little more interesting, and you'll need the right interface circuit to the head, so you don't make it too velocity dependent, or seriously distort the waveforms.

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