MFRC522 RFID reader


I've recently got the MFRC522 RFID reader up and running with the arduino uno using some example sketches from github (

I can read the contents of the blank card which came with the reader fine. However the original purpose of this project was to make a spare copy of the RFID card I use for access to my side gate.

However when I scan that card using the DumpInfo.ino sketch included in the examples from that link, I just get the error message "PCD_Authenticate() failed: Timeout in communication."

I'm still relatively new to this sort of project so does anyone have any tips what that exactly means and if it will be possible for me to create a copy of my card at all?


if it will be possible for me to create a copy of my card at all?

Assuming that your card is the same sort as your reader then no. Those cards have a built in unique ID number. They can not be changed.

However it sounds like your tag is of a different type.

My plan was to get a magic mifare card which has a writable block 0 for the UID code. I know that my gate access card is a mifare 4K card, the arduino script tells me that and it's UID, just none of the data in the other blocks.

Many access control system that use Mifare cards do not use the data in the data blocks but simply use the UID. That can not be changed.
But if you know better then fine, but I thought you were asking for help here, I will butt out, as they say.

Magic mifare card = UID Changeable Mifare card. By Android Mifare Classic Tools App with Android NFC enable phone or Pad you could easily clone the card if card is not encrypted.

  • Android NFC enable phone or Pad's reader chip have to be NXP based.

  • If card is encrypted, then use PM3 to decode the key then clone it.

I have the same problem with “PCD_Authenticate() failed: Timeout in communication.” but all I wanto do is read the card, no writing…