I'm currently doing a project where ideally I will have multiple objects with RFID tags on them that are placed on top of a Adafruit PN532 RFID Shield connected to a Arduino Uno Wifi Rev 2. The idea is that once a button is pressed the RFID reader will read a Mifare tag then "ignore" it then reads the next tag until all are read. How can I acheive this?

I have read some about Anti-collision protocols and the limitations of RFID but was also wondering if it might be possible to read a tag then hold or ignore that tag until it leaves the range of the RFID shield?

I've also read a user on the Adafruit forums had some luck by altering the library that is used, I'll link it for reference, but I've tried the same method but had no luck myself. Adafruit-PN532 Library

I'm new to Arduino so I apologise if I've messed anything out.

Thanks for any help!

  • 2
    what is the actual question? I don't see one
    – MichaelT
    Mar 16, 2019 at 11:47
  • 1
    Sorry MichaelT, the question is how can I achieve what I intend to do for my project? e.g. hold a tag so it is not read again until it leaves the range of the RFID shield. I have edited the original to make the question more obvious I hope.
    – Luke Jones
    Mar 18, 2019 at 16:04

1 Answer 1


You probably want to use UHF RFID for this. The Adafruit PN532 is only capable of reading max 2 tags at a time in an alternating fashion. This is confirmed by the board's designer in the Adafruit forums.

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