Arduino XInput Library

Recently I’ve been playing around with building various alternative controller projects for games, typically using an Arduino-compatible microcontroller acting as an HID input device of some sort. The Arduino ecosystem makes it easy to set up these projects to act as either a Keyboard, a Mouse, a DirectInput Joystick, or a composite device that’s a combination of the above. Unfortunately back in 2005 DirectInput was supplanted by XInput with the release of the Xbox 360 controllers, and modern games have been weaning off of it ever since.

These days, many mainstream games barely support DirectInput at all. Games like Rocket League and Overwatch won’t even recognize a DirectInput joystick – you have to use XInput controller emulation software that can be tricky to set up and doesn’t work with every game.

Wouldn’t it be great if there was a simple, turnkey way to make your Arduino emulate an Xbox controller and work out of the box with these newer games?


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.


Experiment: Wii Nunchuk Controller for CS:GO

Earlier this week I was browsing Reddit and came across this interesting post of someone playing a game of Counter-Strike: Global Offensive (CS:GO) using a Wii Nunchuk to aim. They used a cheap Chinese “Classic Controller to USB” adapter to connect the Nunchuk to their PC, then set up JoyToKey to convert the gamepad inputs into mouse movements.

This was pretty interesting, but I thought I could do one better. You see, I’m currently working on my own project that uses two Nunchuks for a custom controller. So when I ran across that Reddit post, I already had a breadboard on my desk with a Teensy LC, two NXC breakout boards, and two Wii Nunchuks wired and ready to go. Destiny was calling…


HID Buttons Library for Arduino

As I keep working on a number of custom controllers using Arduino boards, I noticed that I tended to build the same sort of data structures every time; things to make it easier to write my own code using the built-in Arduino libraries. One of these bits I kept rebuilding was a wrapper class for the keyboard and mouse libraries that kept track of the keys I was using and their associated output states so that I could set them with a single line of code. Now instead of building yet another version of the same thing for my next project, I decided to turn it into a library instead.

DIY Media Key Footswitch for PC

I spend a fair amount of time down in my garage working on things, and while I’m doing that I like to listen to music. I set up an old computer that runs Spotify and sends the audio to a pair of bookshelf speakers. This setup works great, but it requires using a keyboard and mouse to control it. Often times my hands will be gloved and coated with something nasty: grease, epoxy resin, paint, you name it. So I wanted to come up with some sort of method to control my music when my hands were unavailable.

This is what I came up with: a two button footswitch controller that connects with USB and handles play / pause, next track, previous track, and volume.

Playing Lucio with a DJ Hero Turntable

Earlier this year while I was hard at work on the Nintendo Extension Ctrl library, I challenged myself to try and support as many different types of controllers as possible. As a part of that I picked up a DJ Hero controller for the Nintendo Wii on Ebay for $10.

And then it hit me: with a little bit of effort, I could write some code that would allow me to play the character of Lucio in Overwatch using this turntable! So that’s exactly what I did.


Nintendo Extension Ctrl Library

Late last year when I was putting the finishing touches on the McCree Hammershot project, I decided to use a Wii Nunchuk hooked up to an Arduino for the controller’s movement. Although I eventually got it working, I had to try a variety of libraries before I found one that would even read the data properly. Most of them were convoluted, bloated, or poorly documented. Even the library I eventually ended up using was designed for controlling motors with a Nunchuk, not for just reading control inputs.

It’s now many months later, and once again I’m looking to build at least two more projects using extension controllers. So I decided to fix all of these problems and just build my own library.


Building a DIY Stream Deck (Mini Macro Keyboard)

I’ve been doing a little streaming on Twitch, and a lot of streamers I follow have something called an Elgato Stream Deck. The Stream Deck is a small device with 15 buttons, each of which has its own customizable RGB icon. By configuring the bundled software, users can set button icons and macros to control your casting software, send messages in the stream chat, launch programs, and much much more.

Unfortunately the Stream Deck is out of my price range, at a whopping $149.99 retail.  Fortunately I think I can make something that replicates the basic functionality for a fraction of that price: what I’m calling a “Stream Cheap”.

Although I’m focusing on using this as a replacement for a Stream Deck, at heart this is really a custom macro keyboard. It could be used as a hotkey board for any program. I’m just using it for OBS and Twitch.