My module works fine but it stop to respond ( read codes) in about 2 - 3 minutes, after reboot it works again for 2 - 3 minutes. I have 4 modules, they all working same way. I'm not sure if it is bug or feature
Ahh, no, this is not problem on arduino, arduino responding and working OK, but rfid module is not sending any data TO arduino. So problem is in rfid hardware - this problem is there even when i connect rfid module just to power.
Normally every time rfid module is detecting card it beep - this works for few minutes, then it is dead. So problem is in rfid module, not implementation to arduino or arduino itself.