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Development Highlight: New Schematic and Symbol Library File Formats Are Now the Default

Since KiCad 4.0, work has been progressing to overhaul all the various project file formats that among many benefits, make them far more human friendly, easier to parse and allow easier addition of new features.

For example, the schematic file format used to look like this

EESchema Schematic File Version 5
$Descr A4 11693 8268
encoding utf-8
Sheet 6 8
Title "Video"
Date "Sun 22 Mar 2015"
Rev "2.0B"
Comp "Kicad EDA"
Comment1 ""
Connection ~ 2500 1800
NoConn ~ 2600 3000
Wire Wire Line
	950  3200 950  3450
Text Label 1250 2200 0    60   ~ 0

As part of the transition and eventually the future KiCad 6.0, schematic and symbol library finally have been transitioned to new file formats and made the default formats.

The schematic file format now looks like this:

(kicad_sch (version 20200310) (host eeschema "(5.99.0-1467-g4b4952b09)")

  (page "A3")

    (title "Video")
    (date "Sun 22 Mar 2015")
    (rev "2.0B")
    (company "Kicad EDA")
    (comment 1 "Main sheet")

  (junction (at 375.92 107.95))

  (wire (pts (xy 31.75 49.53) (xy 49.53 49.53)))

  (label "ADR[2..6]" (at 31.75 55.88 0)
      (effects (font (size 1.524 1.524)) (justify left bottom))

All new schematics and symbol libraries will be created using the new file formats. All existing schematics will be converted to the new file format on the first load and all subsequent changes will be made to the new file format. The old schematic files remain unchanged and no further changes will be made. It is still a good idea to make a backup of all existing schematic files just in case something goes wrong.

There are a few things to be aware of when switching between the 5.1 and development branches:

  • Please allow all library symbol rescuing and remapping to complete to ensure that the library symbols will be saved to the schematic files. If either of these steps are aborted, saving the schematic will certainly result in broken symbol links which will require manual intervention to resolve.

  • The symbol library cache is no longer required for the new file format. Converting back to the legacy file format may result in broken symbol links so avoid converting between formats. Schematics are now fully portable without the cache library.

  • Version control software users must add the new schematic files (*.kicad_sch) to ensure change control is maintained.

  • In the short term, the ability to save schematics and symbol libraries to the old file format will be maintained for testing purposes. Once new schematic and/or symbol library features are added, saving to the old file format will be deprecated to prevent data loss between format conversions.

  • The new schematic file format fixes a long standing bug when sharing schematic files between projects. Prior to the new file format, sharing files between projects in a simple hierarchical design required the symbol annotation to be maintained in the shared file(s). This limitation has been removed and the annotation can be changed in the shared file because annotations for the entire project are saved in the root schematic file. Root schematics can also be shared by other projects as well because annotations in hierarchical sheet schematic files are ignored and are not changed by the project.

If you want to give the board import a spin, simply download the latest KiCad nightly. Feel free to report any issues you may find.

Thank you for your patience as we work through any issues with the new file formats. Once the existing feature set is stable, expect to see new schematic and symbol library features added fairly quickly.

Documentation on the schematic file format and symbol library format are available but have not yet been absorbed into the code base’s documentation.

If you want to join in on a discussion on this feature, you may find a forum thread with the developer here

Note Both this feature and nightly builds are in development, please only use them for testing and experimentation

KiCad Development Team

See Also

Development Highlight: Altium Pcb Importer

As a preview of a feature coming in the next major release, the ability to import Altium PcbDoc files is now available in the latest nightly builds. This was thanks to the work of Thomas Pointhuber in MR#60 The board import option can be found under the File > Import > Non-Kicad Board File option and changing the file type filter After which in the import file dialog you must change the file filter

Testing: Eeschema Advanced Canvas Released

The KiCad project recently merged the Eeschema modern canvas code into the development branch. This represents a significant change in the way the schematics and symbols are rendered by using the same modern canvas code used in Pcbnew. The schematic and symbol editing tools will not use the advanced tool framework used in Pcbnew so there will be no new editing features such as advanced selection, snapping, etc. The advanced tool framework features will be introduced into Eeschema during version 6 development.