Rfid not to read credit cards

Hi everyone, I’m new here, and I’m looking for a sample code for the rfid rc522, in order to avoid the reading of credit cards. I mean, when I have a badge (in bundle with the reader), sometimes the reader reads it, but other times it reads credit cards behind the badge. I wonder if there is a way to limit the “protocol” or manage it in a way the reader can understand the different kind of card (not simply comparing the uid with a known list). Sorry if I say something weird. I have Mega, regular and Nano. Thanks in advance
Mark

Your post was MOVED to its current location as it is more suitable.

which credit card?
do you mean you have a stack of RFID (rc522 compatible) cards in your hand that are presented to the reader?

I am reasonably sure the MFRC522 does not read credit cards. :astonished:

If you meant that it will not read its own cards when a credit card is present, that would be entirely expected.

For example it reads my amex

What does it find ?

I’m 100% sure it read my amex (anytime gets a different uid with the same amex).
I have another amex and the same thing happens. Not for visa or mastercard, in my short experience

My badge uid is D5DECA61, my amex gets now 081F25F7, it changes any time

I agree with Paul. Is it an old card? I think that credit cards do NOT use RFID because it's easily hacked. I would contact Amex and determine if your card does, in fact, use RC522 RFID protocol.

The different UID might mean that the card is using a rolling protocol, like your cars' keyfob.

I don't have an MFRC522 hooked up right now, but the next time I do, I will test my credit cards.....

One of my amex is fresh new, so I’m starting to think like I have 2 different badges in the same wallet and have to read more times at once, in order to get the chance to read the allowed badge, the less annoying way.
Any suggestions with a sample would be very appreciated. Thanks a lot, for trying to help!

what do you call a wallet ? is it the typical container where you store coins, bills and credit cards? if you have multiple cards presented at the same time, what you get will vary (all cards get energised and will respond but overlapping signals might blur the answer)

I use an i-clip. I can understand that all cards inside it can interact with the reader, but I hope that the protocol can manage multiple readings, at least giving an error.

If you are to make any sense of this, you obviously must only try to scan the cards completely separately. :face_with_raised_eyebrow:

See Anti collision + Multiple tag reading · Issue #40 · miguelbalboa/rfid · GitHub

Obviously. Do you have any sample code?