2 layers136 × 91.7 mm
One
ergonautkb/one
Ergonaut One is an open-source ergonomic wireless split mechanical keyboard designed by Ergonaut Keyboards.
56 parts210CERN-OHL-P-2.0
2 layers117 × 96 mm
One s
ergonautkb/one-s10Ergonaut One S is an open-source ergonomic wireless split mechanical keyboard designed by Ergonaut Keyboards.
- Size
- 117 × 96 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 50
- Nets
- 36
- Pads
- 299
- Tracks, vias
- 617, 87
- Pours
- 7
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 26 Jul 2023
- Updated
- 5 Jul 2025
Overview
One s is an open-source printed circuit board by ergonautkb, from the ergonautkb/one-s repository on GitHub, published under the CERN-OHL-P-2.0 licence. It is a 2-layer board of 117 × 96 mm with 50 parts on 36 nets, routed with 617 tracks and 87 vias.
It is built around the XIAO NRF52840. Its parts include 18 diodes, 18 switches, 2 connectors and 1 IC. It belongs with the nRF52 and nRF5x boards of this library.
Main components
1README
README.mdErgonaut One S
Ergonaut One S in Modern Case
Ergonaut One S is an open-source ergonomic wireless split mechanical keyboard designed by Ergonaut Keyboards.
Inspiration for the keyboard was taken from these projects:
Idea
We wanted to create a pretty affordable, nice looking, and, most importantly, very DIY-friendly ergonomic wireless split keyboard with Gateron Low Profile switches.
Features
- Low-profile, which will reduce strain on your beautiful hands;
- Split. You can put the keyboard where it'll be comfortable exactly for you;
- Pretty long battery life. 250mAh battery gives up to a month of usage without charging;
- Wide availability and range of compatible keycaps;
- Budget-friendly, because:
- It uses relatively cheap and widely available Seeed Studio XIAO nRF52840 as MCU;
- It uses one PCB design for both halves of the keyboard;
- Everything except PCB's, components and hardware (screws, nuts) can be 3D printed.
- Beginner-friendly, because:
- PCB is easy to solder;
- Cases are easy to print.
- Wireless by design - no unnecessary wires, no unused connectors on the board;
- Free in terms of hardware design. It's licensed under permissive CERN-OHL-P v2 license, which means:
- you are free to manufacture it yourself;
- you are free to sell your manufactured hardware for profit.
Build Guide
BOM and Build Guide can be found in Ergonaut Keyboards Documentation Portal.
Firmware
Firmware can be found in one-zmk-config repository.
Gerbers
| Front | Back |
|---|---|
 |  |
Contacts
- Documentation portal: https://ergonautkb.com
- Telegram: https://ergonautkb.t.me
- Telegram (ru): https://ergonautkb_ru.t.me
Parts
50| Qty | Value | Footprint | References |
|---|---|---|---|
| 18 | D_Small | one-s:Diode_TH_SMD_DUAL | D1, D2, D3, D4, D5, D6, D7, D10, D11, D12, D13, D14, D15, D16, D17, D18 +2 |
| 18 | SW_SPST | one-s:KS-27_KS-33_Hotswap_1U_DUAL | SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW10, SW11, SW12, SW13, SW14, SW15, SW16, SW17, SW18 +2 |
| 4 | MountingHole | one-s:Hole_4.2mm | H1, H2, H3, H4 |
| 3 | StandoffHole | one-s:Hole_2.2mm | H5, H6, H7 |
| 2 | LOGO | LOGO | G***, G*** |
| 1 | BATT | one-s:Battery | J2 |
| 1 | BATT | one-s:JST_SH_Battery_DUAL | J1 |
| 1 | LOGO | one:en_logo | G*** |
| 1 | SW_SPDT | one-s:MSK-12C02_DUAL | PWR1 |
| 1 | XIAO_nRF52840 | one-s:XIAO_nRF52840_DUAL | U1 |
Questions
How big is the One s PCB?
It measures 117 × 96 mm and has 2 copper layers, 1.6 mm thick.
What parts does the One s use?
50 parts, built around the XIAO NRF52840. 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 One s KiCad files?
From the ergonautkb/one-s repository on GitHub, at the commit this page was made from: the board is pcb/pcb.kicad_pcb and its schematic pcb/pcb.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the One s design in my own project?
Its repository publishes it under the CERN-OHL-P-2.0 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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