Week 4 - Electronics Design

Technologies Used:
❖ Eagle
❖ Shopbot
❖ Soldering Iron

Part 1: Eagle

This week our assignment was to redraw the echo hello-world board and add a button and LED (and requisite resistors) to the template board. Before this class I had very rudimentary understanding of electronics so at first the most difficult part was fully understanding how and why the parts worked in a way that they did. The recitation was immensely helpful, but due to how busy I was this week, I still need to spend more time and better grasp some of the concepts.

Designing in Eagle was not as intuitive as expected. Without guidance from TAs I found it difficult to find the parts in the library that I would need because the naming convention wasn't particularly intuitive. At first I attempted to net just by drawing lines across the schematic, which ended up being a huge confounding mess. I only later learned that one could label wires, which helped me clean up my schematic significantly.

Drawing the traces was probably the trickiest part of this week's project. At first the game of snake wasn't nearly as difficult as I imagined. I learned how to adjust the grid, and adjust trace size. Manually drawing the traces was actually a pretty satisfying process, to see all the connections come together. However, my problem would come later....

Part 2: Milling/Soldering

In the previous electronics week I had spent signficiant amounts of time working with the shopbot since I had such a hard time with soldering, so I expected this week's milling process to be fairly straightforward. While converting the traces to an image, and making a trace outline file in GIMP proved easy enough, the actual milling process was intensely frustrating because the traces under the ATTINY44 would keep on colliding and creating shorts. I tried to move them multiple times on Eagle, shrink trace size, and even mess with the endmill size in fabmodules, but none of those strategies ended up completely solving my problem. In the end I had to cheat and use a knife to cut away parts of the trace. I hope to go back and properly mill one when I have the time.

Soldering went fairly smoothly although I'm not yet sure whether my PCB works. Fingers crossed...