Homemade Hardware - Week 6

Programming my marquee board

After diagnosing my upload problems last week, on Wednesday I got around to finishing up the code for my right parenthesis board.

My basic idea for the interaction option was this: I didn’t want the eyes to be on all the time so as to not disrupt the rest of our class emoji, but I wanted something a bit more sophisticated than a basic on/off switch too. The solution I settled on is sort of like a game of skill–if you contact the capacitive sensor pad, a counter will begin ticking up to 10. At 10, the LED eyes light up, and if you release the pad they’ll stay lit. The parentheses LEDs also fade in and out (implementation credit to Tom Igoe’s Arduino examples) during this to help indicate that the action is ongoing, so that you’re not just looking for the green LEDs to flash.

But my board woes weren’t over yet. With all of the traces reconnected, I tried to upload my program to the ATTiny85 using the same method I went over with Brandon–using the Arduino Nano 33 IoT as a programmer while also connected to a power supply set to 3.3V to provide proper current.

The uploads kept failing the same way they did before, so I decided to start nicking traces to see if that would fix the problem. Severing the one between COPI and the transistor controlling the parenthesis LEDs did the trick, but it came at a cost. Having already nicked that trace once before, the copper wanted to pull up from the board. In the course of reworking the connections, the collector end of the transistor also yanked up some of the trace leading to the LEDs.

I resorted to soldering on a bit of wire between the ATTiny and transistor to fix that problem and carefully applied more solder to the other end of the transistor to fix that. Once that was done, I was able to test and verify that the program was uploaded correctly.

Issue is, I can’t really upload anything else to this now. I’m wondering if supplying power at 5V with an Arduino Uno would work, but we don’t have any of those in the shop to test with. As discussed in class, it might also make sense to solder something on to the capacitive pad and to ground to make it a bit clearer how you’re supposed to interact with my board. Assuming I get to that phase, I might try to go the Uno route for reprogramming then.