Keyboard Builders' Digest / Projects
Goobertrax-E
Alex Miller shared his Goobertrax-E, another Hummingbird-like hotswap monoblock with trackball.
Published September 13, 2024
First there was the Goober, then the Goobertrax with a trackball, and here comes Goobertrax-E, with some extra keys and roller encoders. Designed and shared by Alex Miller aka doesntfazer of keyboarddweebs.net.
Keyboard is named the Goober because only a goober would use one. It is a very goofy keyboard. The thumbs keys are super "tucky" and it is awkward to figure out a layout. But once you get used to it, it just might become your favorite keyboard! – Alex.
The Goobertrax-E is a 30+3 key hotswappable Hummingbird-like keyboard using the RP2040 Zero for the MCU. It has a PMW3360 sensor built into the PCB, 3 dedicated mouse buttons, and supports two Panisonic rotary encoders.
Specs
- 30+3 keys
- MX, hotswap
- RP2040 Zero controller
- PMW3360 sensor
- roller encoders
Improving the Japanese duplex matrix
In addition to sharing these keyboards, Alex keeps improving the Japanese duplex matrix.
The first keyboard to ever incorporate the IMPROVED Japanese duplex matrix. […] My improved version which uses pull up resistors on the column pins, eliminates ghosting completely, with most (if not all) low forward voltage diodes – Alex.
I have yet to update the original article, but basically you need to add a 10k Ohm pull-up resistor per column:
The issue that I have always run into (Even when I am choosy with my components.) is ghosting. I needed to find a solution that I could hack into my already designed PCB's that didn't involve adding 2 diodes per switch, Swapping out diodes for ones with higher voltage drop (Which can get expensive very quickly, because these types of diodes tend to be a lot more expensive.) Or cutting traces. What I came up with is adding a 10k ohm pull-up resistor to each column – Alex.
BGKendall discovered another method that works similarly and doesn't require additional hardware that should work with almost any diodes, and the added benefit of working with every MCU, and firmware.
Resources
Published on Fri 13th Sep 2024. Featured in KBD #174.
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