Generate gerber files from script

spuder · December 13, 2015, 6:42am

I’m trying to write a script that will take a board file and generate a gerber file from it.

Being new to kicad, I find myself in over my head. The only documentation I can find on scripting against kicad is here:

http://ci.kicad.org/job/kicad-doxygen/ws/build/pcbnew/doxygen-python/html/classpcbnew_1_1GERBER__PLOTTER.html

Are there any examples of how to generate a gerber file using python/scripts?

Joan_Sparky · December 14, 2015, 1:34am

Can’t help, but eager to see what you come up with.

spuder · December 14, 2015, 2:07am

After a lot of searching, found this script which does most of what I’m looking for.

http://github.com/blairbonnett-mirrors/kicad/blob/master/demos/python_scripts_examples/plot_board.py

spuder · December 14, 2015, 5:44am

To automate creating a diff using travis-ci. A script will be run to generate two .png files, and then those png files will be compared to show differences. This must be automatic (without clicking a button in the gui) as to make it easier to project colaborators to see what changes each other is making for every commit.

spuder · December 14, 2015, 7:44pm

Not generating gerbers, generating pdf’s and then converting to .png files. Generating a visual diff of a .png is very easy.

I found this blog post that explains exactly what I’m trying to do.

http://www.evilmadscientist.com/2011/improving-open-source-hardware-visual-diffs/

bobc · December 14, 2015, 8:03pm

I think it is a good idea, I’ve tried comparing the schematic or pcb files as text, but even small changes can lead to a whole cascade, and it is rather worthless.

The thing that matters is the actual gerber output, so it makes sense to compare that.

Kicad team have gone to great lengths to provide scripting capability - so why the heck not use it? Or are there only certain “approved” uses??

bobc · December 14, 2015, 8:14pm

Ok, you don’t get it. That’s fine. I’ll do it my way and you can do it your way.

hyOzd · December 14, 2015, 9:06pm

I was planning to work on something similar. Do you plan to release your work open source?

hyOzd · December 14, 2015, 9:12pm

When you are at the routing stage, only changes are visual. And looking at the text comparison of two different version of a .kicad_pcb file isn’t really helpful for this.

It would be great if there was tool that can correctly display/highlight changed parts of two different version of a pcb file. But easiest method is the image comparison method as this guy did: http://www.evilmadscientist.com/2011/improving-open-source-hardware-visual-diffs/ or this one: https://github.com/hurik/JGeagle .

spuder · December 14, 2015, 9:28pm

Yes, once I get the .png diff files generated, they will be added to a script.
You can follow the progress of the automation here:

spuder · December 22, 2015, 2:54am

I have finished my solution to this problem and incorporated it in this git repo.

github.com

UltimateHackingKeyboard/electronics/blob/master/scripts/generate-png-diff.sh

#!/usr/bin/env bash
# Takes one or two git ref's as arguments and generates visual diffs between them
# If only one ref specified, generates a diff from that file
# If no refs specified, assumes HEAD

OUTPUT_DIR="./plot"

# Find .kicad_files that differ between commits
###############################################

## Look at number of arguments provided set different variables based on number of git refs
## User provided no git references, compare against last git commit
if [ $# -eq 0 ]; then
    DIFF_1="current"
    DIFF_2="$(git rev-parse --short HEAD)"
    CHANGED_KICAD_FILES=$(git diff --name-only "$DIFF_2" | grep '.kicad_pcb')
    if [[ -z "$CHANGED_KICAD_FILES" ]]; then echo "No .kicad_pcb files differ" && exit 0; fi
    # Copy all modified kicad_file to $OUTPUT_DIR/current
    for k in $CHANGED_KICAD_FILES; do
        mkdir -p "$OUTPUT_DIR/$DIFF_1"

This file has been truncated. show original

It is a python script that takes the current kicad file, plots it as a pdf. It then takes another git commit, and plots that version as a pdf. Both pdf files are then converted to .png files and a compare command generates a diff between them.

Here is what a final product looks like. Blue is before, red is after.

hoijui · September 9, 2020, 10:41am

https://github.com/INTI-CMNB/KiBot can generate gerbers and much more from KiCad files, all fully automated (once the config file is setup).

paulvdh · September 9, 2020, 2:24pm

I did not read this 5 year old thread, instead did a little search for “skidl” and it was not mentioned. If you’re interested in scripted PCB’s then I suggest you reasearch this further.