When I import a LTspice schematic, the connection dots do not appear. PCB layout does have the connection but the connection is not apparent in the schematic editor.
Is there a fix for this?
I did not know this was possible at all.
Browsing through the menu, I found: Schematic Editor / File / Import / Non-KiCad Schematic and then I can select LTspice schematic files (.asc) (or leave it to all supported formats).
Tried some things (pulled some random repositories from github) and it did not work. Then I searched this forum a bit and read that it should be supported but also saw others are having trouble with this.
Tried some more imports, and KiCad was complaining about things like: Symbol “voltage.asy” not found. And similar for resistors, capacitors, LED’s etc. So I cobbled some of those pesky .asy files together from the 'net, and after that I managed to import something resembling a schematic, but it only showed wires, and no graphics for symbols at all.
After some more tests, sometimes I managed to import a symbol together with some graphics, but to me it looks the LTspice schematic importer is very immature. It also seems to simply abort when it does not understand something. It could for example import wiring and the symbols it understand, and create a list of “missing items”. But instead it just aborts. Often I just had an empty screen.
The .asc file format of ltspice seems to be fairly simple. If you really have to, you may be able to import a schematic combined with some guessing and experimenting, or it may just work in some cases when all the planets are aligned, but to me it looks like this importer needs a lot more work before it is useful for the “average” KiCad user.
I see you have already gained the “basic user” status. I guess you can upload a file now. If you upload your ltspice schematic (or post a link to it) then I (or someone else) may have another go at it, but I’m not putting more time into a random schematic just to experiment with importing.
Posting a screenshot of what you can import is also helpful.
You have to install LTspice or extract its library from the installation archive to allow KiCad to find symbols.
KiCad searches for the library at these paths:
Windows:
C:\Users\USERNAME\AppData\Local\LTspice\lib
C:\Users\USERNAME\Documents\LTspiceXVII\lib
macOS:
/Users/USERNAME/Library/Application Support/LTspice/lib
Linux:
/home/USERNAME/.local/share/LTspice/lib/
/home/USERNAME/.local/LTspice/lib/
Or put LTspice symbols in the same directory as the imported .asc file.
Im trying out a simple 1 transistor common emitter amplifier to see how the import function works. Symbols import fine, but not the connection dot. Another issue i discovered is a wire that crosses another wire in LTspice, no connection, KiCad thinks it is connected.
I think pauldvh is correct when he mentions that the LTspice importer need some more work.
Thanks for the 2 replies. And attention you have given to the question.
Peter
This is KiCad’s normal behavior also. Crossings are only connected when there is a junction dot. You can verify this by using KiCad’s net highlight functions, and also verify it on the PCB.
Or at least, that is how it should be…
I still had the project open in which I experimented a bit with the LTspice importer, and net highlighting behaves very strange there. When I attempt to highlight a single wire section, all wires get highlighted
The schematic symbol (from an LTspice import mistake) also highlights all it’s pins.
I don’t know what is happening here. It looks like a bug.
I used KiCad V8.0.4. I’ve attached the project so you (anyone) can try this for themselves.
2024-08-06_asdf_ltspice_import.zip (5.9 KB)
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