Long version:
I have a very odd problem: I connected a Mifare MFRC 522 RFID Reader to my raspberry Pi (it handles communication via SPI). For that I used one of the many Tutorial already on the Internet. At first everything worked fine but after a few days the Reader didn't detect the rfid chips anymore. I was stuck on this for a few weeks, but now i found out, that after a downgrade to Raspbian wheezy, everything works fine and the upgrade to jessie/testing breaks the readers ability to detect rfid chips.
I have seen Threads claiming that enableing SPI + device Tree in raspi-config would solve SPI problems, but it did nothing for me. Unfortunately i need the newest raspbian version, so staying on wheezy is not an option.
Does anybody have a Idea how i can fix or how i can get to the bottom of this problem?
TLDR:
RFID Reader works in Raspbian wheezy, upgrading to jessie+ makes it not detecting cards. Enableing SPI+Device Tree in raspi-config did not help.
