PCB manual signal or net lines

OK, let me start out by saying I am COMPLETELY new to KiCad. Am trying to convert over from Eagle 7.7.0. I have had success in converting my PCB’s to KiCad and even my libraries, but I am just setting things up and have not had a chance to dig into the ‘proper’ way to design or modify my boards. I have been designing PCB’s for long enough that I started doing them manually with the old black tape. When I finally switched to PC based programs, even Eagle, I figured out how to to the PCB layout without going through the schematic step because I was used to that and needed to design things quickly without figuring out the schematic portion of the software. I regret that decision now, but that is where I am. I am going to try and go the correct route from now on, but in the transition and for modifying existing old EAGLE PCB’s without schematics in the system, I have a question…

I am used to simply laying out the PCB and manually placing parts, then connecting each net that should be connected using Eagle’s ‘signal’ selection which lets you simply click on a pin and to all other pins of devices that should be connected together and it strings those little electrical connection wires all over the place. If I make ground planes or some shape and name it the same as I name one of the nets, it will automatically add a wire to that net. That way it will let me manually route each net.

Is there a way to do that in KiCad? I don’t always want to do that, but I don’t want to have to enter all my old schematics just to modify something simple (at least not at first).

Thanks… David

In KiCad V5.1.x there is no such thing.
In KiCad-nightly V5.99 there are some ways to add to and manipulate the netlist directly in the PCB Editor.

Overall KiCad depends a lot on the netlist. Not only for making the right connections, but also for maintaining the proper clearances between nets that do not connect to each other.

It is possible to disable the DRC during routing with Pcbnew / Route / Interactive Router Settings and this may help for making small changes without a schematic (or netlist).

I am curious about your “average” complexity of PCB’s.
Designing a PCB is only viable for relatively simple projects, and for such simple projects drawing a schematic is usually done in 10 minutes or so. (After your initial learning curve with KiCad of course). Therefore I’m guessing that just re-entering the schematic will often be the quickest and best way to make a project complete.

As a child I started by painting the tracks with a ballpoint pen with the ball removed. My biggest project using this technique was an oscilloscope I made (I just needed to have one and it was the only way to have it). Black tape was later. And then IBM-XT has arrived and Orcad (only schematic) and Racal Redac (4x360kB floppies) for PCB. I was able to run Racal Redac on a computer without HDD and write a program to convert the netlist from Orcad to Racal Redac. It was about 1987. Since then, I cannot imagine designing PCB without a schematic :slight_smile:
I strongly urge you to follow this path. Designing a PCB without a schematic reduces the program to a graphic editor, depriving it of 90% of its functionality. Do it as fast as you can, even at the expense of spending more than enough time on some simple fixes.

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Thanks for the reply. I will get used to entering the schematics and really need to do this anyway. I have been drawing my schematics with AutoCad and they have no interaction with my PCB. HOWEVER, I just read a fascinating in-depth review of KiCad 6 which seems to be getting closer to release and It seems to get much closer to what I am used to… The article is by Peter Dalmaris and in it He states under the section entitled ‘Create nets in PCBnew’…

'In KiCad 6 it is possible to create nets in Pcbnew. Therefore it is possible to create PCBs soley within the PCBnew environment, without having to first create a schematic. This is something that many KiCad users have been asking for, finally a reality.

Whether this is a good idea or not is a flame war for another time. Nevertheless, the capability now exists in KiCad 6 and it is both very easy to use and often handy to have.’

He seems to have completely answered my question! Yea!

At schematic you much better see what circuit does, and I suppose drawing the schematic takes less time than defining nets at PCB level. I only suppose as I don’t use pre-V6, and when I will switch to V6 I will certainly also not try it :slight_smile:

Thanks for your reply.
I know, I know. That is the first think I am studying in KiCad so I can fix my problem quickly.

I don’t know if you have found it yet, but in the FAQ area there is an entry to try to help people transition from Eagle to KiCad. It doesn’t cover your specific workflow of PCB only, but it does cover many conceptual differences (for example the completely different library handling). I, personally, haven’t learned Eagle so I don’t know how complete the FAQ item is, but it should hopefully be a good starting point for you.

Thanks… I have installed everything on my office PC and this weekend on my home PC. Have figured out how to put my personal library files where I want them and am now going to dig into making a schematic like I am supposed to do first. Eagle and KiCad really have similar work flows and I don’t think I will have much trouble getting adjusted. I took shortcuts with Eagle that I can’t do in the current version of KiCad, but that is probably a good thing. I just have trouble having time to figure out new software with all the other job responsiblities I have, but I will work it in. I have already found a few features of KiCad that I have been wanting Eagle to have for a long time. I only have the last version of Eagle that was a stand-alone product before they sold out to Autodesk, so I don’t know what they might have enhanced and really don’t care. I don’t want to pay for a subscription service. I have many (200?) boards(79 different products, some with multiple PCB’s) that need converting so I have a long way to catch up. However, all of them up to this point are either single or double sided boards. and only in the last few years have we been trying to use a lot of surface mount components. So I don’t have to figure out the multiple layer things just yet. That simplifies it somewhat. I also never used the autorouting features of Eagle. I tried, but never studied it long enough to get comfortable with it. I spent more time reworking what it did than if I did it manually, so I stopped trying.

Thanks again for the information. I will be sure to look at everything I can find.

I suggest to make a cheat sheet with KiCad hotkeys but divide all of them according to stage of work they are useful.
Be aware that changing the power symbol name (at schematic you see the new value) don’t change its net - that symbol is still connected to its previous net. The real net name is hidden deeper. Because of it you should have all power symbols you plan to use in your symbol library and not place one and change its name at schematic.
And of course, in case of problems, you can always ask here :slight_smile:

Piotr,
Thanks for the great tip! I will print out your message and keep it in mind.

Sincerely,
David

Isn’t it possible to update the schematic from PCB. That is meant for small changes I think, but it might work here too. And you’ll probably get an awfull mess for schematic(because this not a small change), but that is a start.

There is indeed a Pcb Editor / Tools / Update Schematics from PCB but it has limited functionality.

Sometimes I’m dreaming about a full reverse-engineering tool in KiCad. One part would be to load several background images into Pcbnew (photo’s of copper tracks (front, mirrored back, and more) and parts on the PCB), and the next step is a more complete “Update Schamtics from PCB”. This would mean that you first can add schematic symbols to PCB footprints, and then put the whole shebang together with the netlist into Eeschema. Eeschema would then also show all schematic symbols next to each other and also show ratsnest lines between the schematic symbols.

But this is not implemented. The best you can do currently is to draw the schematic separately from the PCB, then update the PCB from the schematics and run the DRC tool to show discrepancies.