Understanding the Xbox 360 Wired Controller’s USB Data

One of my recent projects has been trying to modify some microcontrollers to function as XInput devices, emulating an Xbox controller. The first step in this process is to fetch and then break down the device’s “USB descriptors”. These descriptors are a hierarchy of standardized reports that describe features of the device including who makes it, what version of USB it supports, how it’s powered, and more. By copying the Xbox controller’s descriptors onto my own device, I can convince the computer that my device is also an Xbox controller and will behave like one, and therefore use the Xbox controller’s driver to easily interface with games.

But rather than just copying and pasting the descriptor from one place to another, I want to try and understand exactly what’s going on behind the scenes. I want to understand how the information in these descriptors translates into features of the device’s behavior.


How to Control the LEDs on a Novation Launchkey Mini II

I picked up a Novation Launchkey Mini II controller last year when I was working with those musical floppy drives, and recently I fell down the rabbit hole of Launchpad LED performance videos. That got me thinking: is it possible to control the LEDs on a Launchkey Mini like you can on a Launchpad?

There’s surprisingly little information about this. Novation’s user guide for the Launchkey Mini has no mention of how to control the LEDs. There is some information available in a “programmer’s reference” manual for the Launchkey II (not the “Mini” version), but sadly the LED components don’t function the same way.

It required a bit of reverse engineering and the result isn’t quite as pretty, but I’ve figured out how to do it.