I am using a WIZ820io with an Arduino Nano. If the WIZ820io is the only device on the SPI Bus it is working correctly. But when I add a second device (a MFRC522 RFID-Reader) to the SPI Bus - the module is not working any more. (MFRC522 => Works, WIZ820io => Not working)
I found an application note for w5100 which says that the SEN-Pin must be changed. But the w5200 didn’t have such a SEN-pin.
What could be the problem???