Today’s session was focused on improving the readability of my KiCad schematic before continuing with PCB routing. Although I did not make significant progress on the PCB itself, I spent time understanding how the schematic should be organised and how keyboard matrices are represented using net labels instead of long crossing wires.

What I worked on:

Reorganised the schematic into separate sections for the:
Microcontroller (XIAO RP2040)
OLED display
Switch matrix
Rotary encoder
Replaced many long wires with net labels (e.g., ROW1, ROW2, COLUMN1) to make the schematic much cleaner and easier to read.
Learned the difference between normal text and KiCad net labels/global labels after accidentally placing the wrong type.
Verified that all row and column labels matched the correct GPIO pins on the XIAO RP2040.
Added section titles to improve readability and make the schematic easier for others to understand.
Ran KiCad’s Electrical Rules Checker (ERC) and confirmed there were 0 violations, meaning the electrical connections are valid.

Challenges encountered:

I initially struggled to understand how experienced keyboard designers create such clean schematics.
I accidentally used normal text instead of net labels, which caused confusion because they looked almost identical.
I spent a considerable amount of time checking whether the row and column assignments were correct before removing the original wires.
PCB routing is still proving difficult, and I have not yet found an efficient routing strategy for all the switch matrix connections.

What I learned:

Schematics should prioritise readability rather than showing every physical wire.
Net labels make complex circuits significantly easier to understand.
Organising components into functional blocks improves documentation and makes debugging easier.
Passing ERC does not necessarily mean the PCB is finished, but it confirms that the schematic is electrically consistent.

Next steps:

Finish organising the remaining components and labels.
Update the PCB with the revised schematic.
Continue routing the switch matrix while minimising trace crossings.
Add silkscreen artwork and labels once the PCB layout is complete.
Run PCB Design Rule Check (DRC) after routing to identify any layout issues.