A 32 key ergonomic split keyboard using Seeed Xiao BLE
This keyboard is a variation on my original Nostrum using a Seeeduino Xiao BLE with the battery mounted under the PCB within the case. Not designed to be used without the case.
The aim was to create a case based board while maintaining as much of the original shape and clean lines of the original nostrum pcb.
- 3° Splay on pinky and ring columns
- Choc V1 switch compatible (hotswap or soldered). Hotswap recomennded as the switch plate is integrated into the case.
- Custom mildly tented case including switch sliders.
- MCU not socketed, SMD soldered only.
- Created with the ergogen and KiCad8. Case files created with Autodesk Fusion360.
- Firmware using ZMK, including the RGB Widget module from Caksoylar
- Inspiration from the Hummingbird style Berylline by jcmkk3
- Mousebite breakaway tabs design are inspired by Sadekbaroudi's bykeeb
The case is designed to be fastened from the underside using M1.5x6mm self tapping screws. Feet used are 10x3x1.5mm and 14x3x1.5mm. Left side has space to fit a lipo Battery 402030(180mah). Due to constraints, the right side will need a narrower battery if using hotswap. For my build, I used a 401322 (120mah) but a different size may fit. Example parts listed below. Source your switches and sockets and MCUs where available.
| Part | Link |
|---|---|
| Battery 402030 | https://www.ebay.co.uk/itm/355875616696 |
| Battery 401322 | https://www.ebay.co.uk/itm/195234785175 |
| Self tapping Screws M1.5x6mm | https://www.aliexpress.com/item/1005005469153402.html |
| SMD diodes SOD-123 1N4148W T4 | https://www.aliexpress.com/item/32948518338.html |
| 1.5mm Fibreoptic cable (for led shinethrough) | https://www.aliexpress.com/item/1005005886250822.html |
| Reset button TL3342 | https://www.aliexpress.com/item/1005007506687094.html |
| Power switch PCM12 | https://www.aliexpress.com/item/32912838968.html |
| Feet | https://www.aliexpress.com/item/1005006691343859.html |
Designed in Fusion360. 3d printed. Recommended to print the top case with face down for texured finish. There are two different bottoms, with or without a hole for a reset switch depending on if you want to use one.
The Switch bits need to be fitted before installing the pcb and are a tight fit. Also may require a bit of jiggling to get the slider to seat correctly on install.
The holes on the top of the case allow the charge led and the user led to shine through. I have used fibre optic cable in these holes but it is optional and a tight fit that may require slight enlargement with a screwdriver or small drillbit for the cable to slide in. Any larger in the file and it's a little loose.