2 layers203.5 × 92.5 mm
2 layers96.2 × 97.9 mm
Left Split Keyboard
Ari-Hetti/Split-KeyboardA Split Keyboard With Wireless Capabilities
- Size
- 96.2 × 97.9 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 45
- Nets
- 37
- Pads
- 189
- Tracks, vias
- 265, 80
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 4 Apr 2026
- Updated
- 3 May 2026
Overview
Left Split Keyboard is an open-source printed circuit board by Ari-Hetti, from the Ari-Hetti/Split-Keyboard repository on GitHub, published under the MIT licence. It is a 2-layer board of 96.2 × 97.9 mm with 45 parts on 37 nets, routed with 265 tracks and 80 vias.
Its parts include 17 switches, 16 diodes, 2 resistors, 1 IC and 1 connector. It belongs with the keyboards and input boards and the nRF52 and nRF5x boards of this library.
README
README.mdSplit Keyboard
A Split Keyboard With Wireless Capabilities
Key Features - Description - Components - Board Design - CAD - BOM - Software - Credits - My Other Projects -
Key Features
- XIAO nRF52840
- Rotary Encoder
- Hotswapable Keys
Description
A small 32 key split keyboard with thumb knobs that can be powered wired or wirelessly.
Components
- 2 XIAO nRF52840
- 2 Rotary Encoders
- 32 Hotswap Sockets
- 32 MX Style Switches
- 32 Diodes
Board Design
Schematics
PCB
3D View
CAD
BOM
| Name | Purpose | Quantity | Total Cost (USD) | Link | Distributor |
|---|---|---|---|---|---|
| Switches | The buttons - I will buy myself as the ones I want are around $40 with shipping | 30 | 0 | Cherry | |
| Keycaps | To press | 104 | $7.14 | Aliexpress | Aliexpress |
| Hotswap Sockets | Holds the Switch | 30 | 1.29 | LCSC | LCSC |
| Seeed Studio XIAO nRF52840 | MCU - I will buy myself as by itself is $40 with shipping | 2 | 0 | Aliexpress | Aliexpress |
| EC11E Rotary Encoder | Knob | 2 | 3.96 | LCSC | LCSC |
| 10k Resistor | Encoder Resistors | 100 | 0.3 | LCSC | LCSC |
| 2M Resistor | VBAT Sense | 100 | 0.17 | LCSC | LCSC |
| 806k Resistor | VBAT Sense | 10 | 0.79 | LCSC | LCSC |
| Diode | Keyboard Matrix | 100 | 0.57 | LCSC | LCSC |
| 2 Pin Connector | Battery Connection | 10 | 0.43 | LCSC | LCSC |
| 10nF Capacitor | Decoupling | 50 | 0.34 | LCSC | LCSC |
| PCBs | The PCB order (split up to save cost - 5 each side) | 10 | 6 | JLCPCP |
Software
For this project I will be using KMK, which is an open-source keyboard firmware. I decided to use this instead of ZMK or QMK even with the split keyboard feature still being in devlopment, because I was already familiar with the process due to my experience from my previous keyboard project Hexpad_Highway. For the firmware part I landed on a simple keymap with just letters and couple of punctuation symbols as I just want the keyboard to type. I do plan on adding more in the future when I get to the build and can tinker with the possiblities that entail.
Code:
Credits
This was made using:
- KiCAD - PCB Design
- JLCPCB - PCB Manufacturing
- LCSC - Component Sourcing
- Statis Guide - Split Keyboard Guide
My Other Projects
- Hexpad_Highway - 6 key Macropad with a knob and OLED
- Quadcopter Flight Controller - Flight controller for a 5in quadcopter
- FRC Badge V2 - Hexagonal 555 timer LED chaser keychain
Parts
45| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | D | Diode_SMD:D_SOD-123 | D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15, D16 |
| 16 | Switch | ScottoKeebs_Hotswap:Hotswap_MX | SW1, SW2, SW3, SW4, SW5, SW6, SW8, SW9, SW10, SW11, SW12, SW13, SW14, SW15, SW16, SW17 |
| 1 | 1.0-2P WT | lcsc:CONN-SMD_2P-P1.00_SHOU-HAN_1.0-2P-WT | CN1 |
| 1 | 2M | Resistor_SMD:R_0805_2012Metric | R2 |
| 1 | 806k | Resistor_SMD:R_0805_2012Metric | R1 |
| 1 | EC11 | Rotary Encoders:RotaryEncoder_Alps_EC11E-Switch_Vertical_H20mm | SW7 |
| 1 | GND | TestPoint:TestPoint_Pad_D2.0mm | TP1 |
| 1 | VBAT | TestPoint:TestPoint_Pad_D2.0mm | TP2 |
| 1 | XIAO-nRF52840-SMD | Fixed Footprints:XIAO-nRF52840-SMD Fixed | U1 |
The 39 most common of 45 parts.
Questions
How big is the Left Split Keyboard PCB?
It measures 96.2 × 97.9 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Left Split Keyboard use?
45 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 Left Split Keyboard KiCad files?
From the Ari-Hetti/Split-Keyboard repository on GitHub, at the commit this page was made from: the board is Hardware/Left Split Keyboard.kicad_pcb and its schematic Hardware/Left Split Keyboard.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Left Split Keyboard design in my own project?
Its repository publishes it under the MIT 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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