Basic Keyboard:
The Basic Keyboard consists of the MX HS switches, diodes and RGB leds and a single connector and is arranged in an 18x6 matrix. It was design for hand assembly and low cost. No onboard processing (USB etc.) require an existing module having enough GPIO's, such as a Blackpill or RP2040 or my dev board based on RP2040 which has the exact connector required...
Development Board/Module:
As said above, I include two development modules with the correct connector to make life easier, both support QMK and VIA (code/files supplied). The STM32F411 module works for the keyboard but has an issue with RGB, once fixed I will add it, the RP2040 works out of the box...
Why two boards?
- A fully assembled keyboard (including the processor etc.) in low volume is costly and the possibility of getting something wrong in your first attempt are quite high...
- Hand soldering of the control/microprocessor side is difficult and requires special tools, fully assembled costs for the small module board are low...
- As the main board doesn't contain tiny components, it is fairly easy to hand soldering and the board costs are very affordable ~ $25 including all components...
- The basic keyboard PCB can also be used with other existing development boards...
At the end of the day, if everything works out (hardware and software), you can always combine the two boards into one and bite the cost bullet, I almost certainly will...
Total cost of Basic Keyboard PCB including 100 Hot-Swappable Connectors, 100 RGB leds (SK6812-E) and 100 diodes costs ~ €25... just add MX Switches and Key Caps and a case...
The RP2040 module costs ~ €15...
Prices are given as a guideline, they reflect my costs based on 5 prototype of each board, retail prices would be higher. I supply the code and KiCad files (My GitHub Repo), you submit to JLCPCB/PCB Way etc...
Mike