It’s nice to think the things we make just work and will just keep on working, but obviously that’s not a realistic expectation. This week I’ve been back to two projects that needed a bit of love and attention.
I got both projects up and running again, and along the way learned a couple of things which will help me as I do more making.
The first problem was that the yellow LEDs on my global status indicator had stopped working. A quick look at the circuit showed all the connections looked sound, so I shorted across the button connectors to see if there was a problem there and the yellow LEDs all lit up.
Having diagnosed a problem with the button and checking I had a spare in my box of bits, I desoldered the connectors so I could pop it out of the map. Then I decided to try the button again, while it was out of its snug mounting hole. And of course it worked.
What I think happened is that the hole I’d cut in the board was a bit too tight and was pinching the moving bits of the button that peek out of the sides, stopping something inside the button working properly. So I rotated the button 90 degrees, stuck it back in the map and checked it was going to work before re-soldering the connections to it.
What I learned: components stop working for lots of reasons, not just because they’re broken. I could have saved myself some time by just trying to reposition the button in its hole before starting to take things apart.
The second problem was a corrupt SD card on the Raspberry Pi running my desktop Twitter ticker. I know corrupt SD cards can be a problem for Raspberry Pi users, but until now I’ve never experienced it. When I built the case for the ticker I did consider making the Pi Zero W inside accessible, but that needed more steps and I just wanted the thing finished, so I glued the last panel in place rather than drilling pilot holes and finding some screws to close it up.
Now I used my Dremel to make pilot holes while the case was still in one piece, then levering from the bottom where any screwdriver marks wouldn’t hurt so much I managed to prise the back layer of plywood off the case fairly cleanly.
Then I managed to wriggle the Pi out of the case, reformat the memory card and flash a new OS to it using Etcher. Then I installed Twython and copied my code across and tried to run it. Of course it didn’t work because I’d forgotten to also install oauthlib.
It still didn’t run because I’d forgotten the Pimoroni one line installer for the ScrollpHat HD.
So eventually I got it working and screwed the case together.
I learned two things from this fix: if I’m going to blog about how I build these things I should be more comprehensive in writing up the software requirements, and I shouldn’t put Raspberry Pis in cases that aren’t easily openable.