Quick and dirty magnetic card reader


[nevdull] found himself in possession of a magnetic card reader. What else was he to do but show us all how to read from it using an AVR? He goes through the basics of how the card reader works, as well as how to detect the different card states such as entering, reading, leaving. There is source code to download to try for yourself, but unless you have the same reader, you’ll have to do some modifications. While this doesn’t get you all the way to reading the complete content off of the card, its a great start. Maybe you guys can help him finish up the last bits.


  1. lekernel says:

    you mean, read from it using an avr?

  2. Caleb Kraft says:

    yes, yes I did mean AVR.

  3. SchrodingersCat says:

    Does anybody know of a DIY card writer? Someone told me that it could be done with an old fashioned tape recording head……

  4. goldscott says:

    Very old “proof of concept” I did in college, for use with Microchip PIC: http://goldscott.googlepages.com/cardread

    I’m currently working on a new design. It should be done very soon, just waiting on the PCBs in the mail, and of course getting the rest of the code written.

  5. chango says:

    Reading track 2 should be just more of the same of what he’s doing. He needs to add /strobe2 as an interrupt source and sample /data2 when it asserts.

  6. faelenor says:

    I’ve used a similar reader for my custom alarm system at home! They are really easy to interface.

  7. J4y says:

    I found one that uses the head out of a cassette player and a sound card to decode the cards. But I think the avr has more potential.


  8. LazyMegaMan says:

    “Maybe you guys can help him finish up the last bits.”

    BITS. Get it? GET IT? …No? Ok, nevermind then.

  9. calebkraft says:

    I try to sneak puns in whenever I can get away with it. go back and look, I even went nuts once on the ceiling fan POV, I don’t recall if anyone noticed.

  10. N0QBH says:

    I’ve designed a similar project for a 8 pin PIC micro. http://www.ringolake.com/pic_proj/mag_card/mag_lock10.html

  11. amd says:

    Interfacing to older heads is a bit of a PITA, but Magtek has some newer ones that do USB, serial, or bit serial modes and buffer the data so you don’t have to do much timing sensitive stuff. really not that big of a deal these days.

  12. osceola says:

    Does anyone have a pic card reader schematic whitch stores data to external eeprom or can someone help me with schematic and source code?

  13. lino says:

    Can somebody help me please to convert the wav file to text file to see the track2 from the card?

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