Better Multiple PCB Support In V7?

[PlainName]

Well done for gettng it sorted 

I think your requirement is something of a niche, but the suggestions you make would be useful.

[Kleinstein]

It is not that rare to have 2 boards that somehow should fit togehter.  It would help to get a certain level of support for this.

A tricky case is using stacked boards with multipler connectors (e.g. pin headers) in parallel (e.g. the arduino shields).  In this case the idea with defining a custom connector to combine the connectors is a good idea - this way at least the spacing is the same and no bend pins. At least with many connectors both sides are somewhat symmetric and male and female side could use the same footprint.

Having multiple subsets of supply can be even useful on a single board with isolation barrier.

[SiliconWizard]

At the current state of KiCad, I personally think handling several boards in the same project is going through unnecessary hoops and limitations for a questionable benefit. (As I said, I much prefer handling separate projects but creating custom connectors with pin-out to avoid pin-out errors.)

And for integration, my goal is usually to have 100% of parts with a 3D model in STEP format - ideally from the manufacturers, then export the boards in STEP, and then check integration in a CAD software.
No need to cross fingers hoping the connectors will face one another properly. Just export boards in STEP and check.

[PlainName]

It is not that rare to have 2 boards that somehow should fit togehter.

Indeed, but usually you know what goes on which board before you do the layout.

[berke]

At the current state of KiCad, I personally think handling several boards in the same project is going through unnecessary hoops and limitations for a questionable benefit. (As I said, I much prefer handling separate projects but creating custom connectors with pin-out to avoid pin-out errors.)

How would I have gone about that?  Copy the manufacturer's symbols, and edit the pin names I guess?  I think your custom symbol technique is a great idea  for maintaining consistency between sheets.  I'd only have to edit and update the symbol.

Any ideas for easing the 1-to-1 connections between the connectors on both sides?  Here's how it looks presently.

[EPAIII]

Seems there is a lot more to this than I ever imagined. Than I even could imagine.

As for my project, which is dead simple compared to many here, I have abandoned any thought of doing it in one. Each board will be a separate project for me.

I am the rank beginner here but a thought came to me that might work for a two board situation with one or two connectors running between them. Two boards could be layed out as one snap-apart with the two connector edges facing each other about a half inch to an inch apart. In the schematic both connectors would be shown with connections drawn from pin to pin for all pins. Let the auto router rout those connections between the two connectors in the area that will be snapped out. There WILL be a lot of crossovers. KiCAD then knows all the nets so paths can be checked and simulations run. And the excess copper is tossed away after the boards are separated.

Just a thought. And thanks for all the discussion. It has been eye opening, for sure.

At the current state of KiCad, I personally think handling several boards in the same project is going through unnecessary hoops and limitations for a questionable benefit. (As I said, I much prefer handling separate projects but creating custom connectors with pin-out to avoid pin-out errors.)

And for integration, my goal is usually to have 100% of parts with a 3D model in STEP format - ideally from the manufacturers, then export the boards in STEP, and then check integration in a CAD software.
No need to cross fingers hoping the connectors will face one another properly. Just export boards in STEP and check.

[EPAIII]

Sounds like a great way to confuse the terminology and we have far too much of that in the CAD world already. I would say a project should be the highest grouping of files. It could contain a number of physical items, meaning boxes or assemblies or chassis or even vehicle of trailer sized facilities or whatever. Perhaps there's even two levels of things there, or three. Then those boxes would contain all the circuit boards and other items (big power transformers, etc.) needed for that box to function.

To my mind, that should be the goal. Having the BEST possible noun at each level to describe what is intended at that level. And a "project" would be at the top most level, not the bottom.

Please forgive me if reopening this old thread is frowned upon. I was rereading it and this just seemed to belong here.

What could be nice and useful rather than just a single project holding actually several separate designs would be to add a project container, or something like that. Could be called a "workspace".
In which one could add several existing projects, which would be more easily accessible but would still be separate projects. That would give the functionality without fundamentally changing the architecture or risking screwing something up.

[PlainName]

Let's say I build an ECU. There will be perhaps a couple of PCBs, the connectors between then, the box it goes in, the fixings for mounting the PCBs in the box. And let's add the connectors that plug into the interfaces (but no cables since we don't know where this is going). That's a project, right?

OK, now lets build a car and fit it with wheels and [...], and an ECU. Gosh, that car must be worthy of 'project' (and then some!) but what of the ECU? Is that no longer a project? Do we have to think up a new name for it because it's used in some bigger thing?

No, a 'project' is just an encompassing term for a particular planned aim, in this case the creation of an ECU. Or car. The files that make up a PCB would be a project. The files (spec sheet, manufacturing info, test results) that make up a resistor on the PCB would be a project.

So 'project' is actually the appropriate noun for a collection of files that comprise a thing, whether those are just the schematics and layouts, or include (or, perhaps, are just) the mechanical CAD files and other stuff. That thing may be the smallest part of the collection of a million components en route to the moon. It just depends on where you're standing as to what view you're seeing.

[Doctorandus_P]

As said before, KiCad is still one PCB per project. There are some advantages of combining several PCB's in a single project. For example it makes ERC for the whole design possible, but in the end the difference is not very big. Maybe KiCad will get native support for multi-pcb projects at some time, but don't expect it soon. ** Maybe ** in a few years time...

In the mean time, what you can do: You can create some custom libraries, For example with schematic symbols for connectors, and then name all the signals in the connector. For some time you can also draw lines on Edge.Cuts in a footprint, which allows to draw a PCB outline and put it in a library just like any other footprint (Although this is not the intended use). KiCad also has a built in template system. You can save any project as a template, and then use that template to start a new project. You can find these templates in: Project Manager / File / New Project from Template.

[julian1]

Working with multiple PCBs in the same kicad is possible. And It is a common enough workflow, when there is a need to merge both schematic and pcb layout - from two or more boards. For example when different pcbs are imported and brought together in the same project, then the desired bits of the layout kept from the different boards, and unwanted bits deleted.

What prevents this being a more general workflow is the need to manage designators so that they are unique in the project, and with no duplicates for different boards. So some care needs to be taken to avoid conflicts. Using sub/hierachical sheets can ease this process.

It is possible to imagine a Kicad feature development, where designator IDs would get a unique prefix for each individual board. But this would unreasonably clutter the handling of the common simple case, of one board per project.

And the incremental bang-for-buck is not that high, given one can already create shared symbols, to ensure consistency with things like wiring harnesses,  as well as copy pcb dimensioning indicators between boards, to handle physical alignment of features like edges, headers, mounting holes etc.     

[EPAIII]

When it is said that a single PCB per project is the more common case I think it reveals the hobbyist origins of KiCAD. This is not a bad (or good) thing, just a thing. While I was first a hobbyist in electronics, I also have over 55 years as a professional and most of the electronic things that I have worked with did have multiple PCBs as well as other assemblies. For that matter, even today's hobby systems can often utilize multiple PCBs. Consider an Arduino or other computer on a board with one or more add-on boards stacked on it. Or a control panel added to such a system. I can argue that a single PCB is not the norm for even hobby projects. In fact, multiple PCBs and/or assemblies ARE the norm in electronic projects, even the simplest ones.

I am not involved in the development of KiCAD: I wish I had the coding skills to be but at present, I don't. But I do think that if KiCAD is going to be a major player in the PCB world, that including multiple PCBs and OTHER TYPES OF ASSEMBLIES would be a big concern. Just a thought, but perhaps a separate program for the schematics would be the way to start. That program would need a way of exporting sections of that overall schematic to KiCAD for the individual PCBs. Perhaps it would also need a way of including block diagrams at one or more levels of refinement. Just some thoughts that come to mind.

I can understand that different people can see different meanings in a word.

What should be there is a top level explanation of how the program (KiCAD) works and does not yet work. And that frame of reference should make the meanings of the words used by the developers very plain.

It might also be helpful if there was one recommended work-around for situations like a project that includes more than one circuit board. Have more than one if you want, but DOCUMENT them so a beginner, like me can easily use them. And that work-around should be included in the thinking of the developers in order to preserve it in future versions and also as a goal for a future version where it is included as a fundamental feature instead of just a work-around.