I have an official Gamecube Controller adapter and it works on Windows using the instructions from the wiki.
I also have a Shield Android TV Pro on the latest dev build and the adapter doesn't work. On the wiki it says nothing special is required to make it work, but I couldn't get it to work. When I run a game, a prompt asks me if I want to use the USB advice attached, I click yes, but no buttons work. I switched the USB ports in which I connected the grey and black USB plugs, I also tried to use only one USB port to see if it makes a difference, but nope, still not working. I tried all four gamecube controller ports on the adapter and enabled all ports in Dolphin's settings, but nothing seems to work. I re-installed Dolphin, still not working. My Gamecube controller is an original one.
I also have a Shield Android TV Pro on the latest dev build and the adapter doesn't work. On the wiki it says nothing special is required to make it work, but I couldn't get it to work. When I run a game, a prompt asks me if I want to use the USB advice attached, I click yes, but no buttons work. I switched the USB ports in which I connected the grey and black USB plugs, I also tried to use only one USB port to see if it makes a difference, but nope, still not working. I tried all four gamecube controller ports on the adapter and enabled all ports in Dolphin's settings, but nothing seems to work. I re-installed Dolphin, still not working. My Gamecube controller is an original one.
Specs
Case: Corsair Vengence C70
Motherboard: ASUS Z87-Pro
CPU: i7 4770k {Overclocked to 4.2ghz}
CPU Cooler: Corsair H100i
RAM: 16GB Corsair Vengence DDR3 1600Mhz
GPU: Gigabyte GTX 780 Ti OC
Power Suplly: Corsair RM 850
Case: Corsair Vengence C70
Motherboard: ASUS Z87-Pro
CPU: i7 4770k {Overclocked to 4.2ghz}
CPU Cooler: Corsair H100i
RAM: 16GB Corsair Vengence DDR3 1600Mhz
GPU: Gigabyte GTX 780 Ti OC
Power Suplly: Corsair RM 850