Trace every wire before committing it to copper

Retrospective build log: the 2024 transition from breadboards to PCB.

By this stage the breadboards worked, but the schematics had not kept up with every experiment. Turning that into a PCB was not just a layout exercise: first I had to recover an accurate picture of what I had actually built.

I considered taking everything apart wire by wire. Feedback from other builders convinced me to preserve the working machine instead. I used DIY Layout Creator to make a digital breadboard model, checked connections with a multimeter, and gave each board and chip a coordinate.

That made it possible to work systematically between the physical build, the wiring model and the schematics. It also exposed duplicated logic and opportunities to simplify. Documentation was not something I did after the engineering; it helped me finish the engineering.

The next stages were placement, routing, assembly and bring-up. I used surface-mount passive components alongside the larger logic devices and gained plenty of soldering practice. Eventually the sprawling breadboard build became a working board in a case.

The project files preserve different points in that journey. The schematic and DIYLC PDFs are September 2024 snapshots. I have also included the Gerber ZIP I submitted to JLCPCB, generated on 16 November 2024 with KiCad 8.0.5. It contains the four copper layers, masks, paste, silkscreens, outline and plated/non-plated drill files.

The older KiCad PCB in the repository is historical and is not that later fabrication export. Read the file notes before using either set. For a repeat order, use the original JLCPCB order options rather than assuming the archived CAD job fields contain those choices.

The story of the transition:

An early populated-PCB demonstration: