Comment by convolvatron

Comment by convolvatron 20 hours ago

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i scaned the article but didn't see this. declarative netlist is probably ultimately the right thing. but one place where I got alot of leverage was writing generators for footprints. its so much nicer to say 'this pad is 0.8 x 0.3" and i'd like two rows of them separated by 4mm with a 1mm pitch than to draw little rectangles with the mouse and getting them all to line up. i dont know if more professional tools do this, but integrating that into kicad made me much happier about the whole process.

crote 20 hours ago

Honestly? I want a footprint editor with constraint-based modeling.

The datasheets often show measurements like the horizontal distance between the leftmost side of the left-row pads and the rightmost side of the right-most pad, and the distance between the rightmost side of the left-row pads and the leftmost side of the right-row pads.

Converting that into the stuff you need to enter in the editor (width of pad, distance between center of pad and center of footprint) isn't hard, but it is cumbersome and error-prone. Being able to directly enter it as constraints[0] would make it literally an order of magnitude easier to input, and it would allow for a simple 1:1 comparison with the datasheet for verification.

[0]: Something like https://wiki.freecad.org/images/thumb/7/71/FC_ConstrainedSke...

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  • seveibar 20 hours ago

    tscircuit maintainer here, we actually do support constraint-based modeling for footprints, although we don't use it often because we also support "short string" footprints which are often faster

    https://docs.tscircuit.com/footprints/constraint

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    • mschuster91 19 hours ago

      What I'm missing is something like <pinheader>, just for generic connectors - say, <connector variant="[microusb,miniusb,usba-female,usba-male,vga-male,vga-female]">.

      Also, for resistors, is there a chance for PTCs and NTCs? And <diode> would benefit IMHO from a variant="[zener, schottky, photo]" plus associated parameters for them.

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      • seveibar 19 hours ago

        We think that intuitive element names should be added to the tscircuit spec, even if they're redundant/there are multiple ways to do something. Right now you would probably use a <chip /> (very general purpose), but <connector /> is a great proposal for an element.

        Yes diodes should have variants, I was surprised this wasn't already in the spec and created an issue to add it: https://github.com/tscircuit/props/issues/211

        Yes we would support PTCs and NTCs for resistors, in general anything that helps with simulation, part selection, design intent, functionality, placement or appearance is in scope.

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        • mschuster91 19 hours ago

          > We think that intuitive element names should be added to the tscircuit spec, even if they're redundant/there are multiple ways to do something.

          Definitely makes sense, the question IMHO is what is the best way to interface with existing parts libraries. Making up individual names for each of the probably hundreds of thousands of connector types is going to be a looot of work.

          And then, to add insult to injury, for some connectors there are so many different sub-variants as well. RJ45 with and without magnetics (I see inductors and (auto)transformers aren't present at the moment either) and LEDs, USB-C with some connectors being flush with the PCB and others that are designed to be placed in a PCB cutout... or PCIe connectors which can be had in physically closed and cutout variants (aka, an x1 socket that accepts x4/8/16 cards).

          I hate connectors, in case it isn't apparent :'D

          > Yes diodes should have variants, I was surprised this wasn't already in the spec and created an issue to add it

          Thanks!

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