Robin2:
I don't think I can help any further as there is no useful documentation for the library. I even had a look at the MFRC522.cpp file but I can't make enough sense of it without having any experience using an RFID device.I can't help feeling that your problem is that the program is a lot more complex than it needs to be.
Hopefully someone will come along who knows more about it.
...R
Thank you very much for your time thou. Yes to start of with I too thought all I needed was to place a tag to a reader play a MP3 depending on tag, then once tag was removed to fade out mp3,,,, sounds simple, possibly is, maybe I've just made it more difficult. Originally I was only going to use one nano to interact with two readers, which then would have added a second myserial.
Think I'm going to have to cut my losses short on this project as have a few other projects on the go and make do with what I have.
Thank you for being patient thou, I've learned a little more with the steps you have taken.
ATB