We have just released a joystick app for the Wixel that allows you to turn a Wixel connected to a computer into a USB joystick, with the Wixel’s analog and digital inputs representing joystick axes and buttons. The app and its documentation can be found in the Wixel User’s Guide, and its source code has been added to the Wixel SDK.
We’ll soon be publishing a sample project that shows you how to use a Wixel running this app to convert a retro joystick into a USB device, so stay tuned!
Update (12 September 2013): The Wixel USB Joystick sample project is now available.
Related post: Sample project: Wixel USB Joystick