Skip to the content
2 layers150.6 × 89.6 mmKeyther, the printed circuit board in 3D

Keyther derives from the Cantor Classic keyboard, replacing TRRS with RJ45 (Ethernet), adding hotswappable sockets and slightly increasing switches' horizontal spacing

Size
150.6 × 89.6 mm
Copper layers
2
Thickness
1.6 mm
Parts
24
Nets
53
Pads
351
Tracks, vias
524, 27
Pours
1
Routed
Yes
KiCad
KiCad 9.0 (file 20241229)
Created
28 Dec 2025
Updated
7 Jan 2026

Overview

Keyther is an open-source printed circuit board by MagoSaronno, from the MagoSaronno/keyther repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 150.6 × 89.6 mm with 24 parts on 53 nets, routed with 524 tracks and 27 vias.

It is built around the RJ45. Its parts include 21 switches, 1 resistor, 1 IC and 1 connector. It belongs with the keyboards and input boards of this library.

Main components

1

README

README.md

Keyther Keyboard

The Keyther Keyboard represents an attempt at perfecting the already great Cantor Classic. The name comes from the combination of the substantives Keyboard and Ethernet, due to the use of an RJ45 socket.

Alt text

Special thanks to both diepala and daprice for having paved the way for the creation of the Keyther Keyboard.

What changes from Cantor

  1. The TRRS socket is replaced with the more secure RJ45 (Ethernet) to avoid critical integrity issues caused by accidental disconnection or hot-plugging. Indeed, the Keyther Keyboard supports hot-plugging, as shown in this video:

Watch the video

  1. The design introduces hot-swappable Kailh Choc sockets and handedness by pin (through the addition of a 10k resistor and an added line in the config.h file) You won't have to desolder all 42 switches to change them and you will be able to connect the keyboard even through the right half.

  2. The horizontal space between switches has been increased, accommodating larger hands without additional modifications to the overall PCB size (expept the space for the RJ45 socket).

What does not change

The keyther keyboard keeps (for the most part) the original concepts that were at the origin of Cantor, which are the diodeless design and the use of an invertible PCB design, to ultimately avoid cuttable costs.

Why RJ45 instead of USB-C or magnetic pogo pin sockets?

The main reasons to use RJ45 sockets are their easy soldering, their overall diffusion, and the widespread presence of premade cables of different kinds, like coiled, straight, and flat.

Additionally, the number of pins present on the socket allows the possible addition of two optional communication lines between PCBs for whatever use (namely pins 1 and 5).

Be Aware

The Keyther Keyboard is designed to be used with STRAIGHT-THROUGH CABLES, not the crossover ones.

Always check the cable type before connecting the two halves.

Disclaimer

All the designs and files are provided "AS IS" without any warranty or support.

Links Index

Ordering Guide

Assembly Guide

Firmware Guide

Quick Guide

Bill of Materials (BOM)

The required components needed to assemble the keyboard are the following:

N.ItemNotes
2PCB board
2STM32F401CC BlackPill microcontrollerson AliExpress
420 pin stripesusually included with the Blackpill
42Kailh Choc v1 switchesnamely the Kailh PG1350
42Kailh Choc hot-swap sockets
42Kailh Choc v1 compatible keycaps
2RJ45 sockets (RJHSE type, e.g., the RJHSE-XM80)on AliExpress
1Straight-through Ethernet cableflat ones seem to be more flexible and less annoying when using the keyboard
1USB-C cable compatible with your computer

Ordering the PCB

To order the PCB, you will need the Gerber files present in the Release section. Then, you can either compare the prices on PCBShopper by choosing a dimension of 150x90mm or upload them directly to the PCB manufacturer's website of choice.

You can refer to the Ordering Tutorial page which provides a step-by-step guide on the ordering procedure.

I personally prototyped my PCBs using JLCPCB, primarily due to lower prices. However, these may vary depending on your customs policies and regional shipping rates.

Firmware

It is preferable to flash and check the microcontroller for defects before assembling the keyboard.

The Keyther Keyboard uses the QMK Firmware, specifically the same as the Cantor Keyboard. You can easily follow the guide on the QMK website to customise and compile the firmware.

To add language-specific characters (such as accented or umlaut vowels) you can follow this additional guide.

Unfortunately, at this time, to add the handedness feature to your keyboard you will need to use the QMK source, and, before compiling, add to the cantor's config.h file the line:

#define SPLIT_HAND_PIN B12

Enter Bootloader Mode

To flash the firmware onto the microcontroller you will need to set it in bootloader mode first:

  • Press and hold the BOOT0 button.
  • Press and release the NRST button.
  • Release the BOOT0 button.

Now you will be able to flash the firmware and check if the microcontroller works properly.

Once the first flash has been done successfully you will be able to enter bootloader mode just by plugging in one half of the keyboard while holding down the top-left or top-right (whether it is the left or right keyboard half).

Assemble the keyboard

To assemble your Keyther Keyboard you will need a soldering iron and tin of your choice. You can also follow the Assembly Guide.

Printing the Keyther cases

To 3D print the cases to protect the bottom of your keyboard halves you will need to download the .stl files present in the case folder of this repository and slice them with the appropriate software.

In case you wish to modify the designs, you can download the .step files in the step folder. I've personally succeded in printing them using generic PLA with a layer height of 0.2mm and no supports.

Feedback

You can fill out this form to let me know of any potential improvements or issues with the project.

Have fun!

Parts

24
QtyValueFootprintReferences
21KEYSWkeyswitches:Kailh_socket_PG1350_reversibleK00, K01, K02, K03, K04, K05, K10, K11, K12, K13, K14, K15, K20, K21, K22, K23 +5
110kResistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_HorizontalR1
1RJ45Connector_RJ:RJ45_Amphenol_RJHSE5380J1
1YAAJ_WeAct_BlackPill_Part_LikeFootprints:YAAJ_WeAct_BlackPill_2U1

More from MagoSaronno/keyther

1
  • 2 layers150.6 × 89.6 mmKeyther, the printed circuit board in 3D

    Keyther

    MagoSaronno/keyther

    Keyther derives from the Cantor Classic keyboard, replacing TRRS with RJ45 (Ethernet), adding hotswappable sockets and slightly increasing switches' horizontal spacing

    23 parts6GPL-3.0

Similar boards

  • 2 layers33.7 × 97.8 mmHAN ESP TSS721, the printed circuit board in 3D

    HAN ESP TSS721

    UtilitechAS/amsreader-firmware

    ESP8266 and ESP32 compatible firmware to read, interpret and publish data to MQTT from smart electrical meters, both DLMS and DSMR is supported

    29 parts470
  • 4 layers84 × 82 mmToad, the printed circuit board in 3D

    Toad

    travisgoodspeed/goodfet

    An embedded bus adapter for various microcontrollers and radios.

    241 parts333
  • 2 layers100 × 100 mmCANBuster, the printed circuit board in 3D

    CANBuster

    GBert/misc

    miscellaneous stuff / unsorted

    182 parts99
  • 2 layers50 × 55.4 mmCasserole, the printed circuit board in 3D

    Casserole

    puddly/casserole

    Control GE appliances

    23 parts94Apache-2.0
  • 2 layers67.9 × 47.8 mmPlatine, the printed circuit board in 3D

    Platine

    nv1t/standing-desk-interceptor

    I wanted to intercept the communication between my Flexispot standing desk buttons. This is the progress on the project

    11 parts52CC0-1.0
  • 4 layers90 × 75 mmCM4 2 Backup, the printed circuit board in 3D

    CM4 2 Backup

    olvint/CM4-NAS-MiniPCIE

    Raspberry Pi CM4 based NAS solution board

    21 parts51
  • 4 layers73.9 × 84.5 mmAei, the printed circuit board in 3D

    Aei

    Severson-Group/AMDC-Hardware

    Circuit board designs for controlling advanced motor systems

    54 parts51
  • 2 layers99 × 60 mmPwr, the printed circuit board in 3D

    Pwr

    mfkiwl/KiwiSDR_PCB

    KiCAD PCB files for KiwiSDR project including active antenna and bias tee

    64 parts46

Questions

How big is the Keyther PCB?

It measures 150.6 × 89.6 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Keyther use?

24 parts, built around the RJ45. 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 Keyther KiCad files?

From the MagoSaronno/keyther repository on GitHub, at the commit this page was made from: the board is project/Keyther Mk.I/Keyther.kicad_pcb and its schematic project/Keyther Mk.I/Keyther.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Keyther 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).