A board's first prototype is rarely perfect, but many problems are always the same and can be prevented.

Undersized power rails

The peak consumption of a radio module or a motor can be many times the average. Size regulators, traces and capacitors for the peaks, not the average.

Grounds and return paths

Every current that goes out must also come back. A continuous ground plane under fast signals reduces noise and emissions; cutting it with a trace is one of the most expensive mistakes during EMC testing.

Hard-to-source parts

A perfect part with a lead time of months stops production. Check availability and compatible alternatives before closing the schematic.

No test points

Without test points and a programming connector, testing and diagnosis become slow and expensive. Plan them from the very first prototype.

Ignoring the enclosure

Mounting holes, connectors aligned with openings and component heights must be checked against the mechanical drawing. A mistake here is only discovered when the board does not fit in the box.