simhaonline / bmek

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.

Geekhack Thread, More Pictures 1, More Pictures 2,

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).

A top-mounted version of the original case is being designed under cases/highprofile_plate, to be made from Aluminum soon:

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.