I should have stayed with 7.0.11 (sniff)... I had a bad feeling from the start

Software
1

Upgraded to 8.0.5 yesterday (with a queasy feeling). Unfortunately my feeling was right.
Library (symbol/footprint) migration went OK, all functional. I’ll get used to the new/changed features/interface as well. All OK.

But with simulation, everything failed.
It started with me loading an existing schematic that had always simulated correctly under 7.0.11.
First, a completely unrelated .wks was loaded. (why?) OK, find it, delete it, done.
Then I ran the simulation under 8.0.5. As a reward I got a few microvolts of DC instead of the expected (and correct under 7.0) result.
And I don’t know why. The models are the same, the schematic is the same, the ERC is OK.
The directories are the same, the files are the same, the libraries are the same.

But simulation just doesn’t work as it should.

I’m back to 7.0.11. Post a message when the simulation mess works. Sorry.

2

Can you supply the project as an issue on Gitlab (public or confidential)? I’ve used v7 and v8 for simulation and don’t remember any specific regressions in capability, though I wasn’t doing anything particularly fancy. There don’t appear to be any specific simulation result issues (with the regression label) related to v8 vs v7, but it is possible you have an edge case that hasn’t been caught.

1 Like
3

I second this. I use KiCad 8.0.5 a lot, even the simulation part. And for me it works fine.

As a note to OP for the future: Always make backups, then you can easily revert the KiCad version. Even if it just means to use git. That would prevent such issues in the future

4

I don’t use simulation a lot, but as I remember one of the subjects seriously improved between V7 and V8 was the simulation so if you are using simulation than upgrading to V8 is probably justified.

5

I attach the project as .zip containing .pro, .sch and the diode model.
Also the simulation result from 7.0.11.
As I removed V8, I can’t post a picture of that result, but it was two DC voltages in the uV range.

plot
plot1010×648 53.7 KB

Neg_voltage.zip (9.5 KB)

Thanks.

6

It seems to work for me.

8.0.5:

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image1570×1262 228 KB

8.99:

image
image1738×1312 245 KB

7

Craftyjon was a bit quicker then me, but it also works here.

I first had to struggle through about 10 levels deep of directories, and after that I opened the project attempted to start the simulation and got:

image

But after typing in some basic parameters for a transient analyses I also got:

image
image811×702 78.2 KB

Before that I attempted a operating point analysis to get all the fancy numbers inside the schematic, and it looked like this:

image
image930×685 59.8 KB

It is all different shades of zero’s. Maybe that is what you saw. But I think this is also expected, as there is no DC power source in this project.

1 Like
8

OK guys, Thanks for your efforts. Dunno what went wrong here.
I’ll give it another go. Mercifully my backup/restore system is so good. :slight_smile:

9

image

That message means: “don’t save your simulation results in a .wbk file unless you want to see this error message constantly in the future.”
So I don’t save my simulation results.
Ain’t the KiCAD simulator just great? Nag, nag, nag.

But I do like the new “tick box” approach to showing signals, though. Nice idea.

10

It actually means “don’t save your simulation results in a .wbk file and then share your project on the forum without said .wbk file included” :stuck_out_tongue:

2 Likes
11

Another way of doing it might be: If there’s a .wbk file available, use it. If not: ignore.
There’s no reason at all to store references to .wbk in the main files. And as soon as it’s there, you’re lost. There’s no way of getting rid of it.

The whole simulation thing in KiCAD comes over as a bit of a step-child. Pure perception, but that’s what it feels like.
Everything else is wonderful and I appreciate it a lot. KiCAD is a prime example of professional-quality design software.

12

OK, new update/install. Simulation works now. Other issues are open.