SDG #097 - Lighting Controller Project Part 4 with PCBs from JLCPCB

The lighting controller project reaches the stage every hobbyist looks forward to: the bare boards arrive and the schematic finally becomes hardware. This installment focuses on turning the finished layout into a working assembly, covering how the panels were ordered, what the fabricated boards look like against the design intent, and where the layout choices made in earlier parts either paid off or created assembly headaches.

Assembly is the meat of the episode. Fine-pitch parts and small passives are placed with paste and reflowed or hand-soldered under the microscope, with attention paid to how much flux is genuinely useful, how to keep solder bridges off the closely spaced pads, and how to clean up afterwards so faults are visible rather than hidden under residue. Anyone building their own small-run board will recognise the practical trade-offs discussed here: whether to stencil, whether to hand-place, and how tip choice on a T12-style iron affects the outcome on larger ground pours versus tiny fine-pitch legs.

The more valuable takeaway is the debugging mindset. Rather than plugging in a fully populated board and hoping, sections are brought up progressively so power rails and supporting circuitry can be verified before the more expensive or sensitive devices are committed. That approach catches footprint mistakes, silkscreen ambiguity, and orientation errors early, which is exactly the sort of thing a first revision board tends to hide. For viewers following the series, this part bridges design theory and a physical prototype that can actually be tested, and it sets up the firmware and functional testing work still to come.