Support Design Blocks and prebuild Subschematics

[Thomas Pointhuber]

It would be nice to have the possibility of inserting parts of a schematic or even whole hierarchical-sheets from a special purpose library.

Basically, this would allow simplifying the reuse of existing modules like a step-down regulator or in my case an Arduino-compatible hierarchical sheet.

Somethings similar (they needed it because of lack of hierarchical schematics :P):

https://www.autodesk.com/products/eagle/blog/whats-new-in-autodesk-eagle-modular-design-blocks/
https://www.youtube.com/watch?v=yfsENn6Gq3M

# Version Information

Application: kicad
Version: (6.0.0-rc1-dev-899-g1bce69b9f), debug build
Libraries:
    wxWidgets 3.1.1
    libcurl/7.61.1 OpenSSL/1.1.1 zlib/1.2.11 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.4) libssh2/1.8.0 nghttp2/1.33.0
Platform: Linux 4.18.12-arch1-1-ARCH x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.1.1 (wchar_t,wx containers) GTK+ 2.24
    Boost: 1.68.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.61.1
    Compiler: Clang 7.0.0 with C++ ABI 1002

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_WXPYTHON=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[jean-pierre charras (jp-charras)]

Importing a sheet is already supported by Eeschema.
This kind of feature is really *complex* (although useful).

Just for my info, after having a look at Autodesk link, I'll be happy to know what happens when importing a 8 layers module into a 4 layer board (or the opposite).
Moreover, what happens with Design Rules?

In short: the sample shown is so basic it is ridiculous.

[Thomas Pointhuber (pointhi)]

from what I found out, there pops up a warning when Design Rules differ and you can change it to the board defaults.

I would not care about the board files at the moment. Only the schematic part which for itself seems already pretty useful. I simply assume you cannot import an 8 layer module into a 4 layer board.

The sample explained is more than ridiculous. It simply explained to us that eagle among other things implemented that feature because it does not support hierarchical sheets :D.

I agree that this feature is quite complex. At least it seems like we can finally open and edit hierarchical sheets in standalone mode. At least it seems like adding hierarchical sheets to new projects is possible (but not as trivial as it could be, and probably error-prone when nets are duplicated).

Related issues:
* https://bugs.launchpad.net/kicad/+bug/1786648
* https://bugs.launchpad.net/kicad/+bug/1728248

[jean-pierre charras (jp-charras)]

Adding (importing) hierarchical sheets is easy, and should not create duplicated net issues as long as no global label is used (this is the interest of hierarchies and local labels).

The main issue is more related to libraries:
No problem if the same symbol libraries are used both in the current project and the project from sheets are imported.
However if libraries are not the same (i.e. similar symbols having the same lib_id come from different local libraries and have different representations), subtle errors can be created.

[Thomas Pointhuber (pointhi)]

I would say this feature can be implemented in a safe way when the new schematic file format is in place.

[Wayne Stambaugh (stambaughw)]

I am currently working on a solution for this because it has to be
solved for legacy schematics which we will always have to support. I
don't expect this to be easy to resolve but I'm pretty confident it can
be solved. My goal is to have it done for 5.1.

On 10/13/2018 10:01 AM, Thomas Pointhuber wrote:
> I would say this feature can be implemented in a safe way when the new
> schematic file format is in place.
>

[Hildo Guillardi Júnior (hildogjr)]

One software that I already used
https://www.youtube.com/watch?v=9ZPok7dK5g0&t=33s

had a "clip file" that I could export a selected part of schematic+pcb and use to import in other project.

[Bernd Wiebus (bernd-wiebus)]

Hello

Adding/Importing Schematics is described here:https://www.mikrocontroller.net/wikifiles/a/ab/HierarchicalSchematicsAsBuildingblocksAtKiCad_RevC-EN_06May2015.pdf

However, this might be a little bit old, because it describes the behaviour of EEschema at 2013 to 2015.

And i agree to Mr. Charras about a *komplex* feature. But it is not too complex, and perhaps there could be a better support by doing such things. Special the renaming of designators is sometimes nice ugly.

[KiCad Janitor (kicad-janitor)]

KiCad bug tracker has moved to Gitlab. This report is now available here: https://gitlab.com/kicad/code/kicad/-/issues/2263