We all know that Eagle has its share of shortcomings. Instructables user [westfw] was particularly annoyed by the fact that while Eagle keeps copies of up to 10 revisions of your board, it cannot open those files without resorting to manually renaming each one. Even more frustrating to him is the fact that you can’t use Eagle to view two files simultaneously in order to compare layouts. This made hunting down changes quite tedious, so he started looking for a better way to do things.

While using his favorite open-source gerber viewer gerbv, he noticed that the application let him load multiple copies of the same layer, XORing the PCBs’ colors together. Realizing that with some clever color selection, he could use gerbv to automatically highlight layout differences, he set off to automate the process.

The resulting script works on any flavor of *nix, and should play nice in Windows under cygwin as well. The script reads through Eagle backup files, renaming them and tweaking the colors so that when XORed, they show up as bright red areas in gerbv. It’s a simple yet handy tool to have on hand if you happen to do a lot of PCB design.

Up to this point we’ve used Eagle CAD as our exclusive PCB design and schematic layout tool. But [Brian] has inspired us to try something different thanks to his KiCAD tutorial.

KiCAD is an open source printed circuit board design tool. Since we like to rock the Linux here at Hackaday getting our hands on this was as easy as:

 sudo apt-get install kicad

The version in the Ubuntu 10.04 repositories is a bit older but seemed to work just fine. [Brian] jumps right in with one of our most dreaded tasks on Eagle, designing your own parts. He knows of a nice online tool for automatic KiCAD part generation and walks through the process of building a voltage regulator and importing it for use in your own personal library From there it’s off to layout a power supply schematic for a breadboard PSU. The lesson continues with board layer, as well as the process used for exporting data for PCB fab house. We think this tutorial works well if you’re already familiar with PCB layout using a different software package but it moves a bit fast if this is your first time.

KiCAD seems like a nice tool and we’ve heard from many advocates in the comments over the years. Look for our next PCB design to be on KiCAD as we just need to use it for a while before passing judgement.

Tired of making kindergarten macaroni art PCBs? Check your Gerber files before you send them off to a fab house with a Gerber file viewer. Viewplot , GerbTool’s Viewer , and FAB 3000 Free DFM are all free versions of for-pay software to view your Gerber files. If you use Windows and demo software, these are nice options. If not, you can use gerbv. Allied with gEDA, Gerbv is free, open source software that you can use to view all of your RS-274X Gerber files and Excellon-type drill files. Still being worked on with an active development group, gerbv does not have all the bells and whistles, it does have the ability to delete objects. Check it out after the break.

“You should always check before shipping or you could wind up with holes in the wrong spots. While you’re at it, a little-known feature is that you can also delete stuff!” -[zach banks]

To start, make sure you have gerbv version 2.1.0 or later installed with cairo.

Copy and paste the following lines into a text document and save it however you like:

*
%FSLAX24Y24*%
%MOIN*%
%ADD10C,0.250*%
D10*
X00000Y00000D02*
X10000Y00000D01*
X10000Y10000D01*
X00000Y10000D01*
X00000Y00000D01*
X05000Y05000D03*
M02*

You will now have a simple Gerber file you can view and play with.  Open it in gerbv either through the command line or by starting gerbv and then choosing “Open Layer(s)…”

You should now see a rounded rectangle with a dot inside on the right side of the screen.

If it is not already highlighted, click on the arrow button at the top of the screen to enter object selection mode.

Click around, you should be able to select the various Gerber objects present. You should also be able to draw a selection window to select groups of objects. Pick an object, in this picture it shows the center flash (the dot) selected.  Hit the delete key, and you should get a window that pops up asking if you really want to delete that object. Go ahead and delete that object, that is why you have been provided the little Gerber file.

You should now see the flash gone. If not, you should check to make sure you are in the correct layer. You can now save the revised Gerber file.

Of course, this is just a sample of what you can do with deleting objects in gerbv.  Hack away!

SparkFun has posted an excellent guide to the many different issues you could run into when you finally decide to get a circuit board professionally produced. We assume that most of you aren’t running a professional design firm and will appreciate these tips gleaned from years of experience. They provided a rule list, Eagle DRC, and CAM file to help you get it right the first time. The end goal is designing a board that won’t be prone to manufacturing errors. The tutorial starts by covering trace width and spacing. They recommend avoiding anything less than 10mil traces with 10mil spacing. For planes, they increase the isolation to 12mil to avoid the planes pouring onto a trace. They also talk about annular rings, tenting, labeling, and generating the appropriate gerber and drill files. SparkFun isn’t completely infallible though, and manages to produce a coaster from time to time.

SparkFun naturally followed up this strict tutorial with a guide to unorthodox header hole placement. If you want to learn more about Eagle, have a look at [Ian]‘s overview of Eagle 5 and Ruin & Wesen’s layout videos.