Collect board stats when processing gerber collection

(@mcous has taken over this post to elevate comment below):

New package proposal: @tracespace/stats. It think it could have the same signature as pcb-stackup or be included in pcb-stackup by default.

As a user rendering boards, I often to collect other information about the board for manufacturing / quoting purposes. The following pieces of information should be “easy” to collect:

• Number of layers of a given type
• Minimum trace width
• Number of drill hits
• Drill sizes
• Board size
• Number of pads
  • At the moment, hard to distinguish between TH and SM pads

Both @kasbah and myself have received emails about this sort of functionality. Also see #139

[mcous]

@dontpanic there’s been some progress in the sense that the next major version of the tracespace project will be much more geared towards producing inspectable trees at various steps rather than streaming directly into an SVG string:

1. Abstract syntax tree of each Gerber file
2. Plot trees for each file <- this is what you’d inspect for stuff
3. SVG syntax tree

You can try out (1): npm i @tracespace/parser@next. The rest are still in progress. It would, however, be a pretty tall order to glean any information from the syntax tree itself (though it’s certainly possible! At that point, you’re effectively starting work on a plot tree generator…).

For now, you could try to using the existing gerber-to-svg pipeline and hook into the plotter:

const converter = gerberToSvg(copperFileContents)
const plotter = converter.plotter

plotter.on('data', () => {
  // grab tool shapes, pad flashes, and trace strokes here
  // see https://github.com/tracespace/tracespace/blob/main/packages/gerber-plotter/API.md
})

From there, you could “naively” grab:

• Trace width, by looking at the tool diameter used for stroke plotter objects
  • If your Gerber file uses strokes for copper fills, like Eagle often does, this could be misleading
• Pad size, by looking at the tool shape + size params for pad plotter objects
  • Sometimes, CAD programs (still looking at Eagle) will use strokes for pads, so again, this is naive

Unfortunately, copper spacing is a much harder problem because it involves building up an actual geometric understanding of the shapes plotted rather than simply recording them

[ju5t]

@kasbah sorry, you’re right that there isn’t a great API for this yet.