Does “Timestep too small” basically mean: I give up, kept making time step smaller and smaller but didn’t converge? A bit like recursion limit reached. Therefore its not very useful because its not indicating a flaw but rather is a general statement: Quit because i dont know what else to do.
But yes a simulation is not a primarily synthesis tool, its more of a verification/optimization tool. Though i would really like kicad to have something for gradient descent optimization built into it. Does anybody know if I can you hook simulation launching in python? @holger
@paulvdh I don’t think simulation can ever be user friendly unless you have some AI to set it up for you and automatically figure out whats wrong for you. It can be made user friendly for your singular use case, but generally no.
There are a whole lot of limitations in the user friendliness of simulations, but that does not mean you should not even attempt to improve it. Just that ngSpice is being integrated into KiCad is already a huge step in the right direction. Without that I would not even have attempted a simulation. And on top of that other improvements are being made too. KiCad V8 can show the operating points directly in the schematic. The collection of examples gives users a head start with something that works.
Increasing zooming and panning behavior of the plot windows looks like low hanging fruit to me. Relatively simple to implement, and a direct improvement in the ease of use to the users.
It would also be nice if there were a bunch of symbols which have attached models in KiCad’s default libraries. Just being to pick a opamp from the default libraries, build a filter with it and seeing that it actually works is a huge step to get further motivation to overcome the “other problems”.
Oh yes ngspice. But rather I would like to do all the work inside KiCAD to begin with, because then i dont nee dto work on taking the data back to KiCAD. But then this would require the schematic editor to have a stable API in the first place.
A basic model set is available at Spice models and model parameters for ngspice circuit simulator, covering bipolar, JFET, PowerMOS, OpAmps, voltage regulators and some others. You have to learn how to attach the model to your symbol and how to set the pin sequence.
I just followed the youtube tutorial for the generic opamp, and it all worked as presented. It’s nice to have some basic parts that “just work”. The video is a bit long in drawing the schematic (all with standard parts). I’d think that leaving the basics of drawing a circuit is better left to a separate tutorial. Most people who are starting with simulations probably already know this part, and skipping it leaves more time time to discuss the details that are relevant to the simulation.