mcp_diptrace AGENTS.md

Repository instructions

User-taught PCB house rules

Apply these defaults to PCB generation and demonstration media unless the user explicitly requests otherwise. Datasheets, electrical safety, DRC, mechanical constraints, and manufacturability take precedence.

• For standard 2.54 mm connectors, choose the simplest, smallest practical footprint by default.
• Before placing any physical part, verify its exact manufacturer package and land pattern against the official datasheet. For ICs, also extract the current layout guidelines/example and check the datasheet revision history. Treat the vendor layout topology as the default constraint; document every intentional deviation and its consequence. Missing evidence blocks the PCB build.
• Keep boards compact. Derive the outline from component courtyards plus a sane manufacturing margin, remove unused space, center the layout, and preserve visual symmetry when it does not harm placement or routing. A connector's occupied dimension may define the corresponding board dimension.
• On ordinary two-layer boards, route signals and positive power on Top. Keep Bottom as an effectively continuous GND plane; also pour GND on Top. Break the Bottom plane only when a necessary via or physical constraint requires it.
• Stitch Top and Bottom GND generously across every free region, not merely one edge. On small boards, start around a 2 mm grid, obey clearances, and verify coverage in every part of the board instead of relying only on the via count.
• Connect soldered connector GND pads to pours with a four-spoke cross thermal relief so they remain easy to solder.
• Disable via-in-pad by default. Escape each transition beyond the pad copper edge plus applicable clearance before placing the via. Allow via-in-pad only when the user explicitly requests a compatible filled/capped fabrication process.
• Keep silkscreen readable, close to its associated component, and visually aligned. It must not enter another component's mounting/courtyard space or overlap pads, holes, or vias. Silkscreen may cross copper traces because the traces remain under solder mask.
• For PCB and schematic recordings, show components and connections appearing one at a time in a plausible human construction order.
• Frame recordings from the design boundary: for PCBs, use the purple board outline, fit the whole board with about 10% margin, keep the framing stable, and exclude editor controls. Apply the equivalent boundary-fit rule to schematic recordings.
• After a visual PCB change, regenerate and inspect the PCB, MP4, and GIF. Check the final frame as well as the staged sequence.