I'm in the process of converting from a fullsized KB to a split ten-key-less board (just waiting on slowwww shipping!). Overall, I think this will be a marked improvement, but I was worried I'd miss the dedicated numpad for some tasks, like spreadsheet data entry or doing CAD stuff.
This projects was to create a standalone mechanical numpad with a USB-C connector, STM32F072 microcontroller, and QMK firmware.
First attempt at a USB-C custom numpad. Threw in an RGB LED for debugging. I plan on doing another revision with proper RGB underglow and black soldermask.
For those unfamiliar, QMK is an open source keyboard firmware with enormous flexibility and opportunity to customize your keyboard to behave exactly how you want it to. It has support for a number of micros, and there's even an online configurator for established boards that already support it. Pretty cool!
However, if you've just got fresh PCBs from a fab-house of your custom design, this established support is lacking and a little undocumented, so here are the steps I went through to go from unprogrammed PCB to functional keypad! Please note, this is specific to my board and will not be 100% applicable for different hardware - specifically different microcontrollers!