# Show HN: Stillwind – PCB part selection as constraint solving > Source: > Published: 2026-07-15 17:03:17+00:00 Hi HN, We run an electronic parts search engine, and Stillwind Builder is our attempt to automate the selection step itself: it turns a project description into a PCB bill of materials. At its core, it frames part selection as a constraint satisfaction problem, since your picks depend on each other — a motor driver can't draw more current than the power source is rated for, and every part's supply pin has to be within the voltage range of the rail feeding it. Once the constraints are set up, we evaluate combinations of parts from our database against them. If no combination works, the system adjusts the constraints and tries again. At the end it spits out a BOM. You can try it directly at the link — the purple examples run with one click, or you can describe any project you like. We wrote up how it works in more detail here: [https://stillwind.ai/blog/stillwind-system-builder](https://stillwind.ai/blog/stillwind-system-builder) We'll be in the comments for the next few hours and happy to answer questions. If you'd want to use this on real projects, we're open to design partnerships: contact[@]stillwind.ai Comments URL: [https://news.ycombinator.com/item?id=48923872](https://news.ycombinator.com/item?id=48923872) Points: 4 # Comments: 1