Problems: New Part Generation with Fritzing

Fritzing (fritzing.org) is an open source design package that makes electronics more available and readable, especially for the beginner and maker.  Fritzing diagrams do make it easier to build breadboards using extant products.  I like schematics, but I understand the value of these breadboard diagrams and add them to all of our documentation to help beginners over the hump of the learning curve.

For example, here is a Fritzing diagram for the SwitchDoc Labs External WatchDog Timer:

The purpose of this note is to save others time with the Fritzing New Part Editing tool.

Here is a SparkFun Tutorial that does a pretty good job.

I found the editor and process clumsy, but ultimately successful.  Here are the three problems that cost me a lot of time in the process.  I’m documenting them here to save others time that may be doing the same thing.

The Fritzing Big Red Block

Sometimes I miss the obvious.  I was building a 48 connector Fritzing model for the upcoming SwitchDoc Labs product SunAir (a Solar Power controller / sun tracker and phone charger).  I exported the SVG graphics from Eagle using an ULP and ultimately brought the graphics into the Fritzing part editor.  It looked great.  I wanted to see if the part is the right size and how it looks in the Fritzing Breadboard view, so I connected two of the 48 connections and then added it into the Breadboard view.  All I got was a big red block.

I spend the next 20 hours trying to track down what had gone wrong with Eagle, Inkscape, Adobe Illustrator and Fritzing.  I still had a big red block.  There was nothing on the web about this, except one obscure reference with no answer.  I put on my thinking cap (made of tin foil, of course) and noticed that the color for unconnected was red and I wondered if some graphic was covering the whole board.  I knew that SVG files have lots of graphic elements that are not pins (so Fritzing must handle this) and not a desired connector.  I started wondering if Fritzing would show a red block if I had unconnected pins (46/48 in this example) and so I tried a two pin IC and connected two pins.  I added it in Fritzing breadboard view and the big red block had disappeared and I had two connections.  Success!  As with many of these problems, I felt rather stupid afterwards.

Lesson:  Connect all of your connections in the Fritzing part editor. The Big Red Block disappears!

The Fritzing Board Scaling Problem

I have a SunAir Board that measures 65mm square.  No matter how I set the scale in Adobe Illustrator or Inkscape, it came out about 30mm when I loaded the image in the Fritzing part editor.  It was way too small.  After trying everything I could think of in Illustrator and Inkspace, I finally opened up a text editor and edited the SVG file to change (in the header) from 100% to 200% which sized my board correctly.  Solved.  I know that this has some relationship to the well known 90dpi / 72dpi problem, but this solved my problem.

The Fritzing Adobe Illustrator Problem

Adobe Illustrator is a very good program for dealing with SVG files.  It has clear descriptions and a good layer editor.  It is also expensive, but probably worth it.

Inkscape also works well (it is clumsy with the Mac.  Installation is an issue – but solvable.  The trick is to turn your multi monitor display to one display (or mirror the main display) and then you can use Inkspace (I’m using OS X 10.10.1).

I could not load the Illustrator SVG files (no matter what version of SVG I exported) into the Fritzing Parts Editor.  I would get a Fritzing render error popup.  I ended up loading the Illustrator SVG file into Inkspace and saving it as Plain SVG from Inkscape.  Solved. The SVG file now rendered in the Fritzing Parts Editor.

Now I can produce excellent Fritzing diagrams for the new SwitchDoc Labs products.