Convert symbol to footprint?

I’m making a board where I want a few schematic symbols to appear in the PCB. I realize this is a very unnatural thing to do in the normal PCB work flow, so I don’t have high hopes for an answer. But it can’t hurt to ask.

I’ve already done it manually, by saving the schematic as an image and using the image import tool to make a PCB footprint file. It’s tricky to get the scaling right - ideally I would like 50 mils on the schematic symbol to be 50 mils on the PCB silkscreen. I’m sure that I could eventually get the scaling correct, but I thought I would ask here on the forums first, just in case.

Is there a script that takes a schematic symbol file ( or schematic file ) and generates a PCB mod file?

-Chris

I hereby certify that I am not simply asking someone else to design a footprint for me.

This is an auto-generated message that is in place on the “footprints” section of the KiCad.info forum. If I remove it and ask for a footprint to be designed anyway, I understand that I will be subject to forum members telling me to go design my own footprint or referring me to a 3rd party footprint site.

Do you mean the whole schematic as one image with the intention of the footprints being in the same position on the board as in the schematic? I think you would need to rely on scaling as you have done already.
How many components are you talking about and how complex is the schematic? If it simply a few passive components then it might be simpler to draw your own versions with the symbols on the silk layer and the complete the schematic with lines on the silk layer. Perhaps you could share an image of what you would like to achieve?

Well, here’s an example that inspired the question. In this case, the scaling isn’t 100% necessary, as the PCB is purely artistic/informational and not functional. Although, I was considering running some copper traces that matched the “wires” of the schematic, and gave up because the wires didn’t line up nicely on the PCB grid and it was too much a bother.

As I wrote this inquiry post, I did think about whether there were any real applications for such a tool. It’s a stretch, but I could imagine a PCB that someone makes for educational / training purposes, where the schematic is printed on the board, and the copper traces of the PCB follow the schematic exactly. But that is a real edge case, probably more so than my business card experiment.

The reason a script would be attractive is not because the existing image import process is bad. But rather, it’s a pain to do it repeatedly each time there is a change. I’ve already iterated this 4 or 5 times, and already have a few more changes to make (the back side is in Korean, which is even more fun to deal with). I suppose if the image import program could be run from a script (command line or python), that would easy my pain somewhat. Although I still have the manual and not-precise process of making a screenshot of the schematic after each change (maybe the Export function could help me there, but my initial attempts to use it didn’t seem to do anything).

Well I’ve seen those in the past, and to be honest, it makes sense to see on the sillkscreen a zigzag line for a resistor and a couple of plates for a capacitor. But with everything going SMT, I don’t foresee a major push for a revival of this. Hopefully it will be easier in future to write a script to go from the symbol library entry to something that can be superimposed onto the footprint silkscreen.

Edit: It’s occurred to me that a more recent equivalent for this would be graphics on the footprint for building blocks such as ICs, a mixer symbol, a comparator symbol, that sort of thing, in addition to the IC model ID. But then, with a lot of functions being subsumed by the processor, there is less need for this. And mass produced boards have no incentive to add such graphics.

Maybe this works:

  1. “Plot” whole schematic as .DXF (Or SVG)
  2. Load DXF in a CAD program (or Inkskape for .SVG)
  3. Save the bits you want in separate files.
  4. Import DXF as graphics into Pcbnew (Maybe use SVGtoShenzhen for .SVG)

As long as you keep the drawing in a vector format then scaling should be preserved.

In the Footprint Editor there is also:
Footprint Editor / File / Import Outlines from DXF File, and you can select a layer to import that graphics to.

You could use another tool to draw your schematic, Inkscape, an then use svg2shenzhen to import your design to the pcb. It seems easier an you will only have to invert more time at the beginning to build your assets library, but you will save a ton of time bringing it to the PCB.

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