Creating part, Pins don't connect to wires

Hi. First time user here…

I try to create a simple part but in schematic the wires don’t attach to my pins. Pins are green instead of red.

I so far checked everything, the package pads are assign to component signals, i have no negative messages…

I went through the " [3. Library Conventions]" section, but found nothing.

Any idea?

Hi @holgerlembke and welcome! Sorry, your post was held back by the antispam system for a while…

From your description I’m not yet sure what the problem is. Do you have a library that you could share? (The libraries are in LibrePCB-Workspace/v0.1/libraries/local/.)

I uploaded the library to

I think the problem is that in your component, if you edit the symbol variant, the component signals are not assigned:

You can click on “Automatically assign all signals by name”, then the mapping should be added.

After changing this, make sure to either use “Project > Update Library” or remove the part from your schematic and re-add it. Then it should work:

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Thanks, that fixed it.

I like the way a part is added, but I think it is way to easy to miss a step… I spend the better day of a part and didn’t see/understand my error. It really needs a step-by-step-web-page-guide to find errors.

If you follow the component creation wizard, there’s a signal mapping step. Maybe you changed something in the symbol after creating the component?

In any case, the behavior is a bit weird. @ubruhin do you know why symbol pins that haven’t been assigned a signal can still be connected? Shouldn’t an error be shown instead?

Where is this wizard?

(Build Date: 2019-11-30T13:03:21)

When you create a new component in the library manager.


Oh, my fault. I thought there is a additional component creation wizard. Just like a guided step-by-step-dialog system…

There is! In the library manager, when editing your library, right-click on the components pane and choose “New”. Then the “New Component” wizard will pop up.

It will not warn you if you don’t assign any signals though, maybe there should be a warning. You probably just skipped that step.

They can’t be connected, and that’s visible by the circle of the pin, and the cross of the netline. Both symbols disappear only if they are connected.


Yes, you’re right, but the user’s intent is definitely to connect the wire to the pin. If the wire is placed when clicking without a warning, a new user will probably think it’s connected and that it just looks strange.

So I’m creating another part and now understand my error better… I get the wizard to build component variant one time (when creating a new component). It could be missed easily.

Why not add a message? “Variant “default” has 15 pins without component signal.”