Hardware for BMEK - Bemeier Ergonomic Keyboard
BMEK is an ergonomic keyboard in the spirit of Lyn's EM7 and TGR Alice. Notable differences are the more HHKB-like layout and the and the more symmetric looks due to the space bars and left key cluster arrangement.
Layout
In the current version, only a HHKB-style layout (KLE) is supported - no iso enter, no 2u spacebar for now. Also note that you'll need 2x2.75 spacebars. Most GMK (spacebar) kits only come with one, but you can always use a shift key, or use a 2.25u spacebar and live with a little gap :)
Firmware
Setup QMK and run make bemeier/bmek:default
Source: TODO: Release, Dev
PCB
Both hot-swap sockets and permanent soldering are supported. Connector is USB-C, and is confirmed to also work with USB-C to USB-C cables.
The PCB design was based on the schematics from the Goldfish controller.
All Gerber & BOM files needed for ordering at JLCPCB are under pcb/jlcpcb. It can be ordered with pick-and-place assembly. SMD part costs from jlcpcb quotation (ordering 5 PCBs with pick & place). Only top-mounted LEDs (optional), hot-swap sockets (optional) and USB-C connector need to be ordered separately and soldered by hand. When ordering 5 boards (MOQ), the cost comes out to ~12$ per board, including assembly, but excluding USB-C connector and LEDs.
Fully working PCBv2:
BOM
| Part Detail | Unit Price | Quantity |
|---|---|---|
| Tactile Switches SPST 5.10mm x 5.10mm 0.40mm 50mA @ 12VDC SMD C318884 | €0.07 | 1 |
| ATMEL & AVR QFP-44_10x10x08P C44854 | €3.26 | 1 |
| Multilayer Ceramic Capacitors MLCC - SMD/SMT 22pF 50V 0603 C1653 | €0.01 | 2 |
| Chip Resistor - Surface Mount 10KOhms ±1% 1/10W 0603 C25804 | €0.00 | 2 |
| Chip Resistor - Surface Mount 470Ohms ±1% 1/10W 0603 C23179 | €0.02 | 1 |
| Multilayer Ceramic Capacitors MLCC - SMD/SMT 100nF 50V 0603 C14663 | €0.00 | 12 |
| Multilayer Ceramic Capacitors MLCC - SMD/SMT 1uF 50V 0603 C15849 | €0.04 | 1 |
| Schottky Barrier Diodes (SBD) SOD-123 C8598 | €0.14 | 1 |
| Multilayer Ceramic Capacitors MLCC - SMD/SMT 4.7uF 16V 0603 C19666 | €0.06 | 1 |
| Switching Diode 75V 150mA 1.25V @ 150mA 4ns SOD-123 C81598 | €0.01 | 66 |
| Chip Resistor - Surface Mount 22Ohms ±1% 1/10W 0603 C23345 | €0.01 | 2 |
| SMD Crystal Resonators 16MHz ±10ppm SMD-3225_4P C13738 | €0.38 | 1 |
| Chip Resistor - Surface Mount 5.1KOhms ±1% 1/10W 0603 C23186 | €0.00 | 2 |
| Light Emitting Diodes (LED) -WS2812B-B C114586 | €0.10 | 6 |
| USB-C Receptacle - 632723300011 | €4.00 | 1 |
Cases
3D models for a 2-piece high profile case with integrated plate mounts (intended for CNC-machining from polycarbonate & aluminium) are under cases/highprofile. I'll also eventually release the entire Fusion360 project at a later point, as well as lasercut plate and case files (cases/lasercut).
Contributing
Check out the geekhack thread, or use the issue system on this repository.
License
BMEK Mechanical Keyboard by Jan Kolkmeier is licensed under a Creative Commons Attribution 4.0 International License.
