SDG #156 New Control PCB for the RGB Touch Controller

This installment of the RGB Touch Controller project focuses on the redesigned control PCB, the board that carries the dsPIC microcontroller, power supply and interface circuitry behind the capacitive touch front panel. Rather than a review, this is a design iteration episode: the earlier prototype revealed enough shortcomings in layout, connector placement and signal routing to justify a fresh board rather than more patch wires.

The practical value here is watching how a hobby-scale project matures into something closer to a manufacturable product. Key themes include tidying up the separation between mains-adjacent supply sections and low voltage logic, improving the routing of the touch sensing traces so parasitic capacitance and crosstalk do not degrade sensitivity, and reworking the DMX interface so the controller can sit sensibly in a lighting installation rather than acting as a standalone dimmer. Connector choices and mechanical fit with the enclosure and front panel also feed back into the electrical design, a step often underestimated by first-time board designers.

Assembly is handled with solder paste and hot air rather than hand soldering each part, which is the sensible route for a board with fine pitch packages and a mix of passives. That workflow is worth noting for anyone building similar prototypes: paste plus hot air gives repeatable results on QFN and SOIC parts and makes small production runs realistic on a bench.

For viewers following along, the takeaway is that a second revision is normal and expected. Ordering a cheap prototype run, finding the mistakes, and respinning the board is usually faster and cheaper than trying to salvage a flawed layout with rework.