CEMU Wii U Controller Adapter
Here is an instructional video on how to setup the Wii U gamecube adapter so that you may utilize the gamecube controller with CEMU (Wii U) Emulator.
Links:
Adapter: https://www.amazon.com/Super-Smash-Ga...
Vjoy: http://vjoystick.sourceforge.net/site...
GCN Driver Adapter: http://m4sv.com/page/wii-u-gcn-usb-dr...
CEMU Emulator: http://cemu.info/