While creating a complete DIY racing sim, it was time for a button box. Goal is to be relatively cheap to make with a 3D printable enclosure.

Features 31 buttons (toggles and momentary). Thanks to the FreeJoy firmware button box is plug and play. C clamps for desk mounting.

Components:

• 2x toggle switches with LED - https://www.aliexpress.com/item/1005005545990245.html
• 12x mini push buttons - https://www.aliexpress.com/item/1005009672138666.html
• 4x push buttons 12mm - https://www.aliexpress.com/item/1005007637912547.html
• 2x Metal Switches 16mm with LED - https://www.aliexpress.com/item/1005006389768458.html - For the metal switches, I got 1 locking and 1 reset. Both with 3 position.
• 2x Rotary switches RS16 - https://www.aliexpress.com/item/1005006108961501.html
  • For the RS16, I got two with 1 pole 6 throws. After that I changed one of them for 3 throws.
• 1x Engine Start/Stop, RGB Led Push Button, 3-6V 22mm- https://www.aliexpress.com/item/1005007361580408.html
• 1x Push Button LED, 3-6V, Self-reset, 12mm - https://www.aliexpress.com/item/1005007168217107.html -1x USB Type C male - https://www.aliexpress.com/item/1005007458786256.html -1x USB type C female - https://www.aliexpress.com/item/1005009520776828.html

Electronics and Firmware: I tried 2 different methods for the box.

• Battery powers ESP32 based with Bluetooth connection. Due to the lower power from the battery the LEDs were causing delay in inputs.

• Wired connection is better option when LEDs are involved. So for this project I decided to use FreeJoy firmware: https://github.com/FreeJoy-Team/FreeJoy You will need one STM32F103C8 micro controller. I got a clone board that works great. Buttons and switches are connected to a 74HC165 Button expansion board.

  • This can be purchased or self-made. For 32 buttons you will need 4 shift registers. Follow the guide in GitHub to do the wiring and the software configuration.

Note: You can use Pro Micro with button matrix or PCF8575 expansion boards as well.

Hardware for assembly: -For the front (all black): 4x M4 x 20mm flat head countersunk bolts 2x M4 x 25mm round cap bolts

• For the back side: 10x M4 x 20mm flat head countersunk bolts 4x M4 nuts

• For the C clamps: 2x M8 nuts 2x M8 60 mm bolts (I used this https://www.aliexpress.com/item/1005007663448347.html)

• Mounting the USB type C female jack 2x M2 10mm 2x M2 nuts 2x M3 12mm 2x M3 nuts

Printing: I separated the back of the box in 2 for easier printing with no supports. Non of the part require supports or rafts. Print either on its side or flat.

• For the box frame: I switched to a 0.6 nozzle and layer height to 0.35 some faster printing. Everything else printed with standard 0.4 nozzle and 0.2 layer height.
• 3 wall line count and 10%-20% infill.

Assembly: I did not use any heat inserts. Just screw firmly and it will hold pretty well.

• Back is a bit strange to assemble. You will need to screw the "button-box-back" to the box frame and then screw the C clamps from inside the box.
• "button-box-back-cover" might need some filling to fit. Can be glued if necessary.
• All buttons and switches are on the front plate of the box and can be inserted after you assemble everything else.
• Using USB Type C male and female for extension inside the box.