The Leo Bodnar BU0836A turns your own pots, switches and rotary encoders into a USB game controller. You wire them to the 38 pins, plug it into a PC and it shows up as a joystick called BU0836A, with no drivers and no code to write. It reads 8 analogue axes at 12-bit, which is 4096 steps, plus 32 buttons when wired in a matrix and an 8-way hat switch, so it suits a throttle quadrant, a rudder pedal rebuild, a button box or a yoke whose controller board has worn out.
It runs off USB and works with any sim or game that reads a joystick on Windows, and also shows up on Mac and Linux. The pins are bare 2.54mm headers, so you can push on female jumper leads for testing and solder or crimp your wires for a finished build. We have one new board, and it comes on its own: the plug-on housings and a USB cable are not included, so you will need a USB A to B cable, the square-ended kind printers use.
Specifications
Datasheets
Wiring & getting started
Wiring diagramPot and button
- Get what you need
You need a USB A to B cable and whatever you are wiring in. For a first test, one B10K potentiometer, one push button and a few female jumper leads are enough.
- Find the pins
Hold the board with the BU0836A print the right way up and the USB socket on your right. The pins along the top edge are in three rows at the left: GND on the top row, INPUTS in the middle and +5V on the bottom, numbered 1 to 8. The two rows further right are COLUMNS 1 to 6 on top and ROWS 1 to 6 underneath, with two spare +5V pins between the blocks.
- Wire a pot with the USB unplugged
Always connect pots with the USB cable out. Connect one outer leg of the pot to GND 1, the other outer leg to +5V 1, and the middle leg to INPUTS 1. Give each pot its own three wires instead of sharing, as this keeps the axis steady.
- Wire a button
For up to 12 buttons, run one leg of the button to any GND pin and the other to one of the ROWS or COLUMNS pins. No diodes are needed this way, even for toggle switches. Above 12 you wire a matrix, which is one row pin and one column pin to each button. Row 1 with Column 1 is button 1, and Row 1 with Column 2 is button 2. If 3 or more contacts can be closed at once, which is common with toggle switches left on, add a diode per switch, such as a 1N4148 from our diode kit, with its stripe towards the row pin.
- Plug it in
Windows chimes once and installs it by itself as a USB game controller called BU0836A. If it shows up as Boot or Bootloader instead, the firmware needs loading again, and the files and steps are on the Leo Bodnar product page under Product Downloads.
- Check it works
Press the Windows key, type joy.cpl and press Enter. Select BU0836A, click Properties and turn the pot: the bar for that axis should sweep end to end, and pressing the button should light a number. An axis only appears if its pot was connected when the board powered up, so if one is missing, unplug the USB and plug it back in.
- Set it up in your sim
Assign the axes and buttons in your game the same way as any joystick. If a pot only uses part of its turn, the free Windows configuration tool from Leo Bodnar can stretch that range and reverse an axis. Rotary encoders also need that tool: pair them on an odd input first, such as 1 and 2 or 3 and 4, then set the type to match your encoder.