Week 5 - Electronics Design

Task: redraw the echo hello-world board

Learning Eagle and making own Echo Board

This week I learned how to design PCBs using the program EAGLE, from schematic to board layout, and how to add a button and LED onto a pre-existing board design.


I walked through the Sparkfun tutorial on using Eagle, copying the hello.echo board on the website for connections and parts. Some notes: make sure your net wires start exactly on the end of leads, not too far in, because that doesn't actually make a connection. Also, its a good idea to simply draw and rename wires to connect in order to keep the schematic simple and easy to read, without lines going everywhere. Here's the schematic without my added modifications:

I then went back and added the LED and switch, connecting them to different pins and adding the appropriate resister for the LED, and a pull-up for the switch.

Designing the routes was also non-trivial. I ended up looking to Neil's board for help on making sucessful routes and using my button to double as a jumper. I also decided to try netting the extra space to ground using the polygon and ratsnest tool. Don't forget to test that it passes all the design rules! Here's my final design:

Milling on the Modella

In order for the fab modules to read my PCB design, I needed to modify it to the proper format. To do so, I needed to turn off all layers except the top and use Gimp, an image manipulation tool, to change the board to black and white and invert colors and make the outline file.

Should be smooth sailing from here! Another note: when using the updated fab modules, you should choose all the options at the top first before choosing the modella type. I had a bunch of trouble printing since without doing so the command/code isn't generated and the fab modules won't communicate properly with the modella. Milling:

Gathering the parts...

A stuffed board!

Where to go from Here

I didn't test out whether my board will work, so crossing fingers for two weeks from now! I also still hope to understand what's going a bit better, but that's for later.