I've added some changes to the code in order to handle a SNES Mini Controller too!

Basically:

• The gamepad is now a 12 buttons device, always (doesn't matter the Mini Controller you're using)
• The report the usb device is sending is now a 2 bytes report instead of a 1 byte report (1 byte allows 8 buttons, 2 bytes allows up to 16)
• Some "init operations" need to be done in order to initialize the SNES Mini Controller before reading the data. This can be done over the NES Mini Controller too (nothing happens).

There's a TODO list on the github project with some extra details, known issues and improvements I have in mind, so check it out if you're interested! https://github.com/theisolinearchip/nesmini_usb_adapter/