Trying to refer to a specific RFID PN532 card in code for attendance system

Hi, My group and I are using RFID PN532 and we currently have the code printing the UID value in the serial monitor. What we now want to do is refer to a specific card's UID value in the code. (We want to say that if card (example) 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF is read then it will be marked as present in school. We then want that if it is scanned a second time it is marked as absent) If you are able to please help that would be great!! Thanks!!

You want?

This isn't a restaurant for ordering code.

What have you done code-wise and what is the error message you are getting.

We are not getting any error messages yet because we do not know how to code it. That is the issue. We do not know how to name a specific RFID card in code and then refer to it. That is what we need help with.

Is there a way to keep track of the cards in the code?