This is a sim racing button box designed to fit around the Aiologs sequential shifter. The enclosure fits around the shifter itself as a sleeve and takes advantage of the mounting point bolts built into the shifter's housing. I did not originally create this with sharing the design in mind, so please check the notes below!

Parts list:

•  "Arduino" Pro Micro (HID capable, cheap)
•  An assortment of aluminum buttons from Amazon, 16mm (6x) and 19mm (4x)
•  1x Heavy duty toggle switch
•  4x 5 pin rotary encoders (with push button) and metal knobs
• Soldering iron/wires/any connectors you might want to use

Build instructions:

1. Print the enclosure and the top plate (top plate holes may need to be modified depending on your buttons/switches). To slide the enclosure over the shifter you will need to remove the top right (when viewing the shifter from the right side) bolt, slide the enclosure down, then screw the bolt back in through the printed part hole.
2. Create the software that will run on your microcontroller. I used SimHub's excellent and easy-to-use Arduino configuration tool. It allows you to assign pins to various peripherals and generates the code required to use them. In this case a 4x4 button matrix (8 buttons, 4 buttons built into the encoders, and the 2 “button” toggle) and 4 rotary encoders. Make sure to enable “Gamepad” mode. Flash the new software to the Arduino!
3. Mount the components in the top plate and connect them per the pinout generated by SimHub (or however you assigned them in your custom code). You will probably need to solder wires to your Pro Micro depending on which you purchase. I recommend small gauge wire (22 or smaller) to fit it all into the enclosure at the end. I configured my button matrix just based on what was physically convenient to wire.
4. Plug your MCU into your PC and test the inputs using windows game controller utility (search windows for “Set up USB game controllers”).
5. Close it all up! I used wires that were on the larger side so this was a little tricky, but just be careful not to pinch or strain any connections.

NOTES/IMPROVEMENTS:

• The top plate is press-fit, so you may need to slightly adjust it's size (or scale it) depending on your printer. Screw mounted would probably be a better solution…
• There is no mounting point in the enclosure for the MCU, mine is just floating around in the wire mess. Hard mounting would be a good improvement.
• I purchased my shifter JANUARY 2023, make sure to check the bolt pattern on the exterior of your shifter before printing in case it has changed (before or after this date). The cutouts for the bolts on the printed enclosure could probably be simplified a lot anyway…

UPDATE - NEW VERSION ADDED: I've added a second version of this design that allows for M3 hex nuts and M3 cap head screws to be used (like these), rather than just having the button plate be press-fit. These are the file names that end in “_with_screws”. The hex nuts slide into slots under the screw holes. The fit is very tight (it will take a little effort to insert them into their slots), but this is to help prevent stripping the slot from over-torquing a screw.