Discovering Eagle CAD

Basic Stamp, schematic I was reading a story on some other interesting project and came across a program called Eagle CAD. At that time I thought it was "just some CAD program", but I soon found out it is a) free for non-commercial use, and b) it is made for designing PCBs (printed circuit boards). So, I used up the whole Sunday afternoon and learned how to work with Eagle CAD. And - wow, nice program!

At first you design the schematics. The pretty large library didn't cover the Basic Stamp so I designed my own library with a lot of help from a tutorial on the web. Once you get the hang of the not so modern GUI everything is pretty straightforward. At first I used wires instead of copper routes - which is not the same. The latter are printed on the board while the former, well, are wires.

Basic Stamp, board Though I didn't actually need to create a PCB I did one anyways. Eagle CAD is able to create a board from a schematics file. What you have to do yourself is arrange the items. The program than automagically creates the routes. Neat! I just could not figure out how to enforce the use of a single layer board - it seems that two layers is the minimum (hence the red and blue routes).

Basic Stamp board
The layout of the board reflects the current state of my Basic Stamp board - the fat Basic Stamp in the middle, a power driver to the east, a piezzo buzzer (and a resistor on the flip side) in the northwest and lots and lots of connectors all around. The photo is a bit older and does not show the power and serial connectors.