kicad-developers team mailing list archive

[Sylwester Kocjan <s.kocjan@xxxxx>]

Hi Pepijn,

On 14/10/2020 20:00, pepijn de vos wrote:

> I think there are a few ways to go about it, which don't exclude each
> other. One is to extend the logic that adds the currents for voltage
> sources and resistors to also add transistors.

Current release version of KiCad populates simulation signal list based 
on schematic components. Recently I added function NGSPICE::AllPlots(), 
which will retrieve names of all vectors from current simulation run.
For your transistor issue I believe all you need is to rewrite 
DIALOG_SIGNAL_LIST::TransferDataToWindow() to use this function. Your 
NGSPICE object is under aParent->m_simulator.

Here's a couple of links:

1. Function to change:
   https://gitlab.com/kicad/code/kicad/-/blob/16d5f959814f10c64e2d5a8f14fc8357c5de6fee/eeschema/dialogs/dialog_signal_list.cpp#L49
2. Function that should be used:
   https://gitlab.com/kicad/code/kicad/-/blob/16d5f959814f10c64e2d5a8f14fc8357c5de6fee/eeschema/sim/ngspice.h#L63
3. Simulator object:
   https://gitlab.com/kicad/code/kicad/-/blob/16d5f959814f10c64e2d5a8f14fc8357c5de6fee/eeschema/sim/sim_plot_frame.h#L354

Best regards & can't wait to see the results :)
Sylwester


On 15/10/2020 15:15, Tomasz Wlostowski wrote:
> On 14/10/2020 20:00, pepijn de vos wrote:
> > Hey all,
> >
> > I'm a sw dev and recent IC design graduate, who made it his mission to
> > improve open source tools for IC designers.
> > To this end I've been playing with the recently released Sky130 PDK,
> > which is an open source PDK that does not require any annoying NDA's and
> > will actually allow sharing IC designs.
> >
> > I've been looking at eeschema a bit as one of the options to do
> > schematic entry and simulation. However, I found that the integration
> > with ngspice is very limited at the moment. So I'm interested in making
> > this better!
> >
> > The first problem I ran into is that it can't plot the currents of a
> > transistor no matter what you add in terms of spice directives. More
> > info:
> > https://forum.kicad.info/t/how-can-i-plot-transistor-currents-after-a-simulation/25324/8
> > So I have several questions.
> > Would this be a good first issue to tackle?
> Hi Pepijn,
>
> Sure, go for it - and if you'll find it too hard as a starter, there's a
> ton of other issues in the simulator/ngspice integration...
>
> https://gitlab.com/kicad/code/kicad/-/issues?scope=all&utf8=%E2%9C%93&state=opened&label_name[]=ngspice
>
> > I think there are a few ways to go about it, which don't exclude each
> > other. One is to extend the logic that adds the currents for voltage
> > sources and resistors to also add transistors. Another is to update the
> > simulator UI to populate the signal list from the raw file, rather than
> > its own idea of which signals were saved, so that you can add custom
> > .save statements and plot them.
> I would by default tell the simulator to log all node voltages/pin
> currents (including transistor pins). Anything else (that is internal
> currents, etc.) should be parsed from .save directive (so I'm more in
> favor of option 2).
>
> > For example, two other things that would be great to add is a way to
> > plot algebraic expressions of different signals,
> This looks like a nice feature in the longer term. If you're interested
> in developing it, I could offer some (but not much) help due to my
> current workload...
>
> Tom
>
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