We have based our keyboard development following the Open Sourced Parameterized ergonomic keyboard done by Matt Adereth and modified for our developement by Balthazar team. Here you can find our detailed documentation on a current modification and here QMK firmware that we use in this development. Below you can see our modifications and although this design is currently divided in left and right we will merge this into a single keyboard controller for our laptop.
New keyboard PCB has been developed and adopted to a Balthazar dimensions
Details on a new Keyboard module
• ISO standard keyboard layout • an ergonomic design • minimally (1/10th ) reduced keyboard size • silicone rubber waterproof overall keys blanket • microcontroller shared between keyboard, charger, safety control and a touchpad PS2 to USB
The computer keyboard system with microcontroller (for now an 8-bit Atmel built into a small Sparkfun ProMicro board) A normal ISO keyboard layout is used. An option is given to test the ability of the microcontroller to handle also the control for PSU board and the touchpad module data transfer to USB. Keypad and touchpad user activities are usually mutually exclusive – so this seems ok. Charger control is active a couple of seconds on startup of the system, so this is also ok. In case of some charger error there is a mechanical switch on PSU board to stop charging. In this way three functions would be fulfilled in a single microcontroller – connected to the system with one USB.
Keyboard pcb has some dimensions already defined by the LCD's dimensions of 13.3 inch in diagonal: 290mm x 180mm. The width is the most determining factor for the keys raster which is about 17mm – instead of the regular 19mm. The keys have some ergonomic solution that gives some additional design touch.
The keyboard switches are important but are for now very typical low cost membrane switches. A little better solution are the softer (silicone) – but still membrane – switches (not much love for the higher quality Cherry buttons). The idea is to have a waterproof (silicone) layer over the whole board. The board can then already act as a top cover. The feel of silicone rubber is preferred to that of natural rubber.
Keyboard Schematics: File:BalthazarKeyboardSchematic02.pdf
Bill of materials: File:BalthazarKeyboard-Bill.ods
PCB is ready for prototyping as KiCad files are available at our Github pages.
Those will be regularly updated as schematics and PCBs are continuously improved and optimised.