[sdiy] What's the best freeware schematic capture and PCB layout software

[mskala at northcoastsynthesis.com]

On Mon, 13 May 2024, Donald Tillman wrote:

> I don't see a "tension" between a pretty diagram and a correct netlist.
>  Features in one are not at the expense of the other.

Often they are.

For example, the "power flags" in many Kicad-generated schematics, which
serve only to tell the electrical rule checker that a given net is a power
net, are to the detriment of making the schematic look good.  I've also
added things like screws to a schematic just to make them appear in the
BOM, or mounting holes to make them appear and be properly linked to the
right nets on the board, because that was more convenient than doing it
any other way, even though I would not include these things in a schematic
intended solely only for display purposes.  In the other direction, a
schematic meant for humans to read would preferably include notes, voltage
readings, waveforms, and so on, which may be difficult to add in a
schematic capture program that only really has feature support for things
that will affect the netlist because that's all it's designed to create.

When humans only have limited time, and time is money, the time they spend
doing something that is useful for only one of the netlist or the printed
diagram, is literally at the expense of the other.

There are also indirect ways in which the design or encouraged use of a
CAD program can affect the appearance of the schematic, beyond the direct
features of the program.  For instance, Kicad comes with a lot of
third-party libraries and users expect to use those.  Some of the symbols
in those libraries look bad; and others look okay by themselves but are
drawn to a different scale from symbols in other libraries, so that two
symbols from different libraries next to each other will clash.  And
there's little incentive to spend developer resources on prettying up the
symbols because these issues don't affect the netlist, which is the
priority.  The developers made, and continue making, a choice about what
their priorities are.

-- 
Matthew Skala
North Coast Synthesis Ltd.