WIZnet Developer Forum

Multiple SPI-Devices


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???

SEN means SPIEN pin #6 in W5200.


but i can’t set this pin. It doesn’t have a pin outside of wiz820io :frowning:.

WIZ810io have no SPIEN pin. you are right.
WIZ810io doesn’t support mulit-slave.

I recommend that you will replace WIZ820io with W5200 ehternet sheild.
refer to


The above my post is wrong. I am sorry that I mis-understood W5200 with W5100.
W5200 have no problem using multi slave.
So, WIZ820io have no SEN pin.

If you can’t use it with others, It maybe have another problem.


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