ULK
Low profile split keyboard with Corne 42 Layout and Cerry ULP switches. (6mm height)
Install / Use
/learn @Goga64/ULKREADME
ULK
Low profile split keyboard with Corne 42 Layout and Cherry ULP switches. Made to be used on top of a laptop keyboard to provide the ultimate split experience on the go.
Contents
Disclamer
This Design is still under development and has Issues! Due to the availability of the ULP switches only the Click version was available which is nice for home, however too loud for work at public places.
Issues:
Current Issues:
- Hole attachment point interferes with USB-C charging cables. (These also truned out to be not needed so they will be removed) FIXED in V1.0.3 please check which gerber file you are uising
- Battery connection should be changed form a through hole to SMD, so there are no chances of shorting a battery when putting keyboard on
Things to do:
- Solder up the proper batteries.
- Add support for solar charging.
- Build a version with 35g PG1316s.
- Change the reset button to a lower profile SMD version.
- Add a 3x5 option.
Gallery
<img width="3246" height="1263" alt="ULK v7" src="https://github.com/user-attachments/assets/6b71d21b-0977-4e59-85f4-adc084f5ee60" />
BOM
Main Components
| Name | Specification | Notes | |------------------|-------------------------------------------------------------------------------|---------------------------------------------------| | Switches | Cherry ULP or Kailh PG1316S | You can find more about the ULP at Cherry_MX_ULP | | Keycaps | 1U Kailh PG1316S Keycaps | — | | Diodes | 1N4148W in SOD-123 package | — | | Microcontroller | SuperMini NRF52840 | Compatible with nice!nano V2 and alternatives (GitHub link) | | Power switch | 7Pin Mini Slide Switch | — | | Reset button | 3x6x4.3mm push button | Will change to an smd one after testing samples | | Battery | ~100mAh 401525 LiPo or smaller | Prototype photos show 750mAh HiV battery due to shipping delays |
Optional Components
| Name | Specification | Notes | |-------------|---------------------------------------------------|---------------------------------------------------| | Non-slip | 1 mm Silicone Rubber Strip, Self Adhesive | Increases overall thickness to 6.8mm | | Kapton tape | Polyimide insulating tape | To cover through-hole components on bottom of PCB |
<!--- ## BOM Switches - Cherry ULP or Khali PG1316S Keycaps - 1U Kailh PG1316S Keycaps Diodes - 1N4148W in SOD-123 package Microcontroller - SuperMini NRF52840 - compatable with nice!nano V2 and it's alternatives https://github.com/joric/nrfmicro/wiki/Alternatives Power switch - 7Pin Mini Slide Switch Reset button - 3x6x4.3mm push button - Will probably be changed, when I get a sample of buttons. Battery - ~100mAh 401525 Lipo or smaller - On the pictures a 750 mAh HiV battery is used due to battery shipping taking a long time and I had those lying around. Optional Non-slip - 1 mm Silicone Rubber Strip Self Adhesive (thinkness increases to 6.8mm). Capton tape - to cover the through hole components on the bottom side of the pcb. -->Firmware
You can use the standart Conre ZMK firmware.
I use a modified verion of the MC Technology's zmk-config GitHub link. My version also allows for 4 halfs of a spit be connected with to one Dongle at the same time.
