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PCB design starts with a README

· nabla B, Bochum · Original from

Before we open KiCad we write down what the board should do and let an LLM turn it into a block diagram. Every one of our boards starts this way.

The most expensive mistake in PCB design is the wrong board. The second most expensive is a board whose purpose the team does not agree on, because nobody wrote it down. We prevent both with the same tool: a text file in a git repository, written before the first schematic symbol.

The routine: a new repository, a structured README covering function, interfaces, power and open decisions. Then the README goes into an LLM with a request for a PlantUML component diagram. The .puml file is committed, not the image, and rendered locally with the PlantUML CLI. Whatever the model misunderstands we fix by hand; the format takes an afternoon to learn.

The point is not documentation. It is thinking. Whoever will not write down the requirement will not build the board cleanly either. And a block diagram that fits on one screen answers in thirty seconds what the thing is, before a review even starts.

We use this approach for every board and in architecture reviews for customers. A complete example with README template and GitHub Action is on the blog.

PCBKiCadArchitekturPlantUMLLLM

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