Fritzing Part Creation

Creating a custom part in Fritzing requires a little bit of work but it isn't too bad if you can start with a part that is already in the library.  I can't speak to any problems that may be found if you try to create one from scratch but I would guess that the most difficult part would be creating the breadboard image.

The seven segment display that I have is a different footprint and pinout than any of the other common cathode displays that come in the standard library.  I used these basic steps:

• Select the part that is closest to yours
• Select the Part >  Edit menu item
• Load the newly created images for the schematic and PCB views
• Update connector settings
• Save as a new part

Really the only one of these items that was tricky is creating the image for the PCB view.  This is because the layers of the SVG file are what denotes the layers that get associated with the PCB layers.  Each pin in the SVG image has to be named ConnectorX, where the X is the number of the pin.  Then all of those are grouped together and the group named Copper1, then another group is created which includes the same items and named as Copper0.  Also a silkscreen shape can be added as the final layer as well.  I'm sure this sounds quite confusing but if you open the SVG file of an existing part, ungroup each layer, and view the object properties you can see how the existing library parts are labeled.  A little tip for arranging your pins and getting the spacing right  when using Inkscape - I used the "straight line" tool to draw little guide bars to check spacing.  Also, Inkscape has the ability to align shapes so you can select a row of pins and align them to each other's middle to assure your pins are in a straight row.

One hiccup I had was that for some reason when the part was created an I.D. for the silkscreen layer was not created in the Fritzing part file.  The .fzp files can be edited with a text editor and per the advice of a developer on the Fritzing forums I manually added a line to the file which defined the silkscreen layer.

Throughout this process I asked a few questions on the Inkscape forums and the developers there always respond very quickly.  They did mention that the part creator will be re-vamped in future versions so perhaps it will be possible to do all of this from within Fritzing in the future. 

Fritzing

So I looked around my random parts box trying to decide what to make with the Arduino board.  I had a couple segmented LED displays so I thought I would try to make up a little temperature gauge using a thermistor to read the temp and display.

I figured this would be a good time to play around with Fritzing and plan the breadboard and make up a little schematic for reference.  Things were going pretty well and the tool works quite nicely - I started out just grabbing a few parts and placing them to see how things snap into the breadboard sockets and how the wires connect up.  From my experience it seemed easier to me to make connections on the breadboard view.  When trying to make connections on the schematic view, the "wire" mode was kind of finicky and it took several attempts to get the cursor in just the right position.

Once I was familiar with the basics of the program I went to actually create a decent representation of my design and hit a roadblock - the old displays I have from Radio Shack are not in their parts library.  That sent me off on a quest to figure out how to add parts to Fritzing.  It doesn't seem too difficult but I need to grab an SVG editor - I plan on using Inkscape since it is open source.

Looks like the build is on delay for now.  I could just skip the whole drawing and documentation aspect but there really isn't any urgency to building the project.  It would be better if I take the time and properly document things so if I want to re-build it later I'll have the information handy.