Fighting with computers

Computers are not always friendly.

Tuesday, March 13, 2012

Arduino RFID

This time I am interested on a particular application of this technology: My university has moved to RFID picture IDs for students and I was curious about how difficult it was to read the cards from an Arduino board. Our system is using 13.56 MHz cards, so I ventured into eBay territory. Almost anyone can type "Arduino RFID" there to get plenty of cards that allow you to read (and write) RFID tags/cards.

For those of you living in a cave, RFID is a wireless technology that allows you to both power and interact wirelessly with a card or tag that contains a digital unique identifier that optionally may include some rewritable memory too. Tags or cards themselves do not have nor need a battery but they contain a microchip and a coil to gather energy from nearby readers. That means that the card and the reader need to be pretty close for this to work (that is why the technology is dubbed as NFC or Near Field Communication).

After buying one card and waiting the usual two weeks for things to travel from China to my home using regular mail, I have tested the card with the sample software and I am pleasantly surprised on how simple this is: Reading and Writing works outside the box, though I have some problems with source code commented in perfect Chinese (a language I cannot read). Some understanding of Mifare cards is needed if you want to use the cards memory storage, as there are some security mechanisms you need to understand.

4 Comments:

  • At 6:46 am, Anonymous Anonymous said…

    Hi Miguel,

    May you please add two Arduino examples to deal with your RFID device. I got similar device and I try to understand the attached source code and I didn't :(
    Please some help

     
  • At 6:47 am, Anonymous Anonymous said…

    one example for reading from device and the other for writing :)

     
  • At 4:08 pm, Blogger Miguel Sánchez said…

    The key for understanding how it works is in this drawing: http://dl.dropbox.com/u/9063914/Captura%20de%20pantalla%202012-05-15%20a%20las%2015.56.12.png

    Each read or write operation can only happen once card selection and authentication has been successful.

    Please bear in mind you need to know the keys for your read/write attempt to be succesful.

     
  • At 3:39 am, Anonymous hanum said…

    related with RFID, you can download this article here http://repository.gunadarma.ac.id/handle/123456789/2162

     

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