This Odd-Looking DIY Keyboard Features a Built-In Trackball

One of the major reasons for the rising popularity of mechanical keyboards is improved ergonomics. Even with a conventional keyboard layout, the predictable tactile feedback of a mechanical key switch can improve typing comfort. In a similar vein, trackball mice can help reduce the repetitive stress injuries (RSI) associated with the unnatural movement required to operate a standard mouse. It’s anecdotal, but my issues with tendonitis disappeared after I switched to mechanical keyboards and trackball mice years ago. I assume that Redditor tenstaana would agree, because they built the UniChunky — a custom mechanical keyboard that incorporates a trackball.

The UniChunky keyboard does look quite strange, but its design is the result of ergonomic functionality coming before aesthetic preferences. A neat, orderly grid of keys may be pleasing to the eye and easy to manufacture, but it doesn’t suit the natural resting positions or movement of human fingers. The strain of holding one’s fingers in an unnatural position and the strain of lateral finger movement is what causes tendonitis or even carpal tunnel syndrome. The layout that tenstaana chose is a more aggressive evolution of keyboard layouts like that of the popular Microsoft Ergonomic 4000. It keeps typist’s hands and fingers in a comfortable position, which is further enhanced by the mechanical key switches and integrated trackball mouse.

Everything about this keyboard is custom, down to the huge PCB that includes a Raspberry Pi RP2040 microcontroller. To account for the relatively small number of I/O pins, the PCB uses a shift registers to monitor the keys instead of a typical keyboard matrix. That also completely eliminates issues like ghosting. An optical sensor monitors the movement of the trackball and a large scroll ring surrounds that ball. The PCB also supports other controls in place of the trackball, including a joystick. Every key switch has its own RGB backlight LED. A TFT screen above the trackball shows the current configuration, layer, and so on. It even has haptic feedback.

All of that fits inside of a beautiful aluminum case that tenstaana designed to be cut on a CNC machine. The plan is to release the next revision as an open source project, so stay tuned for that.