Hi. I own a 8BitDo SF30 BT Pro pad, i managed to connect it to my RPi3B+ bluetooth with D-input mode (Start+B). See the manual if required. I didn't manage to connect it with the USB cable lol It doesn't work.
Raspberry Pi 4
For information, Recalbox IS NOT compatible with Raspberry Pi 4 yet.
Pour information, Recalbox N'EST PAS encore compatible avec le Raspberry Pi 4.
The Recalbox Team.