

Kb42
Split 42 key keyboard utilizing Redragon low profile keys
- Size
- 162.6 × 106.4 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 23
- Nets
- 40
- Pads
- 176
- Tracks, vias
- 373, 0
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 16 Feb 2024
- Updated
- 20 Feb 2025
Overview
Kb42 is an open-source printed circuit board by ty-davis, from the ty-davis/kb42 repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 162.6 × 106.4 mm with 23 parts on 40 nets, routed with 373 tracks and 0 vias.
Its parts include 21 switches, 1 IC and 1 connector. It belongs with the RP2040 boards of this library.
README
README.mdkb42
Split 42 key keyboard utilizing Redragon low profile keys
It is heavily inspired by the Budgy while also being influenced in design by the Cheapino.
Build guides coming soon. Source code for the firmware for the keyboard can be found in my qmk fork. In the assets folder you can find some pics and the .uf2 firmware files that you can download to flash the board yourself without having to build the entire qmk compilation suite. One of the firmware files is a via compatible version of the firmware for the keyboard, and the other uses a very basic layout which is quite limited.
Via firmware guide
Because my firmware isn't in the official via firmware repo, in order to use via with this keyboard you will need to follow a few extra steps the first time you use it.
After flashing the via specific firmware
to the keyboard and connecting the keyboard to your computer,
navigate to the via website and press authorize device. Select kb42 in the dropdown that appears and
you'll enter the app.
Usually you can start changing the keymaps to the board
at this point but we need to complete an extra step. Go to the settings
icon in the top center and enable the option
that says Show Design Tab. Now a new paintbrush icon
has appeared above. Select that tab and click Load Draft Definition. That will prompt you to upload a
json file that corresponds to some via specific definitions
for this keyboard. Upload this json file
which can be found in this repo -> assets -> firmware
-> kb42_via-definition.json
Once that file is uploaded and the via app accepts it
you'll be able to change all of the configuration for
the board. You can see the configuration that I'm using
for the board by uploading the configuration file called
kb42_TyGuy60401_layout.json which can be found in
the firmware folder.
Parts
23| Qty | Value | Footprint | References |
|---|---|---|---|
| 21 | SW_Push | ProjectLocal:SW_Redragon_LowProfile_Reversible_PCB_1.00u | SW1, SW2, SW3, SW4, SW10, SW11, SW12, SW13, SW14, SW15, SW16, SW17, SW18, SW19, SW20, SW21 +5 |
| 1 | AudioJack4 | KeebioLocal:TRRS-PJ-320A-rev | J2 |
| 1 | Pico | RPiPicoLocal:RPi_Pico_SMD_TH-REV2 | U1 |
Questions
How big is the Kb42 PCB?
It measures 162.6 × 106.4 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Kb42 use?
23 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Kb42 KiCad files?
From the ty-davis/kb42 repository on GitHub, at the commit this page was made from: the board is kb42.kicad_pcb and its schematic KiCad-RP-Pico-main/Test/Test.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Kb42 design in my own project?
Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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