miguelbalboa/rfid

Not able to read cards (specifically) unless a card/tag is present while the board starts

Opened this issue · 6 comments

moussie369 commented

Step 1: Describe your environment

  • OS version: W10 (latest)
  • Arduino IDE version: 1.8.15
  • MFRC522 Library version: 1.4.x
  • Arduino device: nano v3 (clone)
  • MFRC522 device: firmware is 2.0

Step 2: Describe the problem

Cards won't be read unless one is present when the program starts, if trying to read a card after some times it won't detect anything.
It works fine when using older versions (1.3.6 is the last to work)

Affected file(s) or example(s):

*All examples/any code using this library
*DumpInfo

Steps to reproduce:

  1. Reset the board
  2. Wait ~10-15s
  3. Place a card in front of the reader

Observed Results:

Nothing happens and it won't read anything until the board is reseted.
It works fine if only using tags or if a card/tag is present while it's rebooting.

Expected Results:

  • Detect/dump the card informations to serial
Rotzbua commented

Did you test 1.4.0?

moussie369 commented

Yes, 1.3.6 was the last to work

Rotzbua commented

Can you test current version without connected reset pin and replace code with:

MFRC522 mfrc522(SS_PIN, UNUSED_PIN);   // Create MFRC522 instance
moussie369 commented

The arduino IDE and platformio won't build with UNUSED_PIN

Rotzbua commented

Sry, ofc with scope MFRC522 mfrc522(SS_PIN, MFRC522::UNUSED_PIN);

moussie369 commented

Well I think I found the culprit, since then I bought a few more nano clones and it seems to work ok with them.
I was kind of freaking out trying to figure out what had changed since march until I realized it.
I still don't get why it's working only with 1.3.6 and earlier, but unplugging rst and putting MFRC522::UNUSED_PIN didn't do anything

edit: unfortunately trying to flash the bootloader from the other boards I didn't pay attention and blocked the nano, I remember it was quite an adventure to get them to work when new so I won't try today