I have a 5100-based shield and am getting a WIZ820io.
The test sketch W5500HelloWorld and WIZnet library are in the mbed system as potential imports.
I tried a build for nRF52-DK which compiled and loaded OK.
(I disabled DNS and put in a IP and MAC addresses.)
When I run it fails to get as far as printing out the MAC address, showing 000000 instead.
I wonder if anyone ever tried to build this for nRF52 - or any other mbed-supported platform that I should try?