Homemade Hardware – Week 02
For this week’s homework, we had to finish soldering our chip programming shield for the Arduino, and design our circuit with Eagle. I started by practicing soldering, time and time again (and got burned multiple times in the process), and after finishing the shield we started in class it looked something like this
During the weekend, I got my Soldering station delivered (thanks Amazon), and decided to re-watch the videos in the lab, plus the NASA soldering tutorials and practice more. To do so, I used an Arduino Proto shield, and soldered two sockets, one for the ATTiny85, and one for the 328, so I have scaling options in the future.
As these proto-bords are two sided, I kept most of the wiring on the bottom, resulting in a clean shield that is easy to carry plus put on and off. One thing I would improve in it, is having female headers on the I/O, so that I can keep the shield on while I use the Arduino as a power source for other circuits. Even though it could use a couple of further mods, the shield acctully saved me a lot of time in programming the chips, since using it feels more like a ‘plug and play’ instead of reorganizing the breadboard whenever something doesn’t work.
After the soldering, I started practicing Eagle in order to create the board for the next class. I actually found the workflow of typing commands to Eagle quite meditating after you dive into a long board design session (with the headphones on), and discover a couple of hours have passed (Oh no). As discussed in class I started with the Schematic view, and was looking for a ATTiny85 schematic symbol online, but all the ones I found wer’e surface mounted, and as we will be covering that topic down the road, decided to use a standard 8-pin socket, which in terms of holes will fit perfectly with the ATTiny85 socket.
After thinking about how the sensor would connect, I suddenly realized since it has it’s own logic board, it would probably make most sense to have headers that would connect to the appropriate place in the circuit but would allow me to mount the sensor’s logic board in a different location (Nice! now to the board design part).
After trying many different configurations, I landed onto this one which is able to fit all the electronics needed in the circuit into a rather small form-factor, but giving appropriate space between lines. One thing I did realise while designing in board view, is that my VCC and GND, were just symbols, and meant I didn’t have any way to ‘wire’ them up, and so I had to go into Schematic view and create headers where power and ground actually connect to the circuit.