miloh / noisebridge-badge

A sketch for a potential first button badge for noisebridge. Built in gEDA

noisebridge-buttonboard

a light up lapel button. simple soldering project.

gEDA Terminology & Description

gEDA is a suite of tools

• gschem - electronic schematic editor that has some operational similarity to old versions of OrCAD
• gnetlist outputs a number of netlist formats from gschem, part of the sim workflow
• schdiff - works as a git difftool and uses imagemagick to generate visual diffs of gschem schematics
• refdes_renum a tool for giving unique 'reference designations' to symbols in a sch file
• gaf stands for gschem & friends, an eponymous cli for use with gschem & friends.
• spice tools -- thofficial spice package for use with geda-gaf. with complete symbols, gnetlist creates spice compatible netwlist
• pcb, aka PCB or what I'll call gEDA's PCB - a powerful and fun floss circuit layout program

Project Hierarchy and using gnu Make

The main directory contains templates for a schematic built using gschem: and layout files for geda's PCB:

*.sch

*.pcb

These all get processed using Make, with the included Makefile. Note this Makefile hasn't been tested with more than a few versions of gnu make.

To use the makefile, you run make and supply a goal. The following list is from a system with tab completion, which supplies the user with the list of goals available from the makefile. Some of these will require user actions, like providing the correct filetypes in the local directory, and ensuring they use the cvs-based keywords that sed will process the files with, and using git to tag versions.

clean                  gnetlist-bom          hackvana-gerbers.zip  Makefile              
schematic-template.sch osh-park-gerbers.zip  pdf                   gerbers               
hackvana-gerbers       list-gedafiles        layout-template.pcb 
osh-park-gerbers       pcb-bom               ps

This makefile uses the commonly available sed and echo, the less available 'gaf' project from geda, and is intended for use by a hardware designer using gschem for schematic capture and geda pcb for layout.

Finally, it also uses git, specifically the git-tag comand to template the keywords in the schematic and layout templates. The templates should be availabe for checkout from the early revisions of the project). Versions released for manufacturing should include annotated version tags using semver (vXX.YY.ZZ, XX=major YY=minor ZZ=patch)

Bug reports are welcome, create issues on github or send them to miloh at froggytoad dot net

Git submodules

This project uses git submodules for libraries of schematic parts and footprints.

First, update the git submodules after cloning the project and regularly during development unless you want to freeze the schematics and parts to a specific branch (which may totally make sense for some completed projects).

git submodule update --init --recursive

Updating submodules is important to remember, because when checking out dev branches or earlier tags of the project, you will have to update the submodules to get the correct version of parts (symbols and footprints) used during development. The following command should also be used after checking out earlier versions to keep the project synced

git submodule update --init  --recursive

Note that gschem should use a local file 'gafrc' with a line in scheme that configures the directory for local symbol libraries.

PCB preferences must be changed to find local footprints, I do this in the PCB gui currently but I imagine there are other ways.

Using schdiff with git's difftool

schdiff allows the user to compare schematics from different versions.

example showing a diff from the current HEAD to 30 commits back:

git difftool -x schdiff HEAD~30 project.sch

Importing images into gedaPCB

Many folks use potrace and pstoedit to work with images and geda PCB

eps images can be converted into pcb layouts with the pstoedit tool. Potrace can be used to convert bmp images to eps, or 'encapsulated postscript' format.

Inkscape can be used to convert svg or ps content to the eps format. Note that paths should be 'smoothed' by adding control points, and text paths should be exported with a high DPI raster, which can be entered in the eps save as dialog.

The pcbfill option is required for proper treatment of 'filled' polygons, like images of text that you want to import.

The following example converts a Noisebridge logo into a pcb layout that can be imported (File -> Load Layout to Buffer) into any layout you are working on.

pstoedit -f pcbfill Noisebridge_logo.eps Noisebridge_ButtonLogo.pcb -ssp