The assignment for this week was to write an application that interfaces with one of the boards we've made in the past weeks. I really haven't completed this assignment yet, sorry. My understanding of how all of this works isn't where it functionally needs to be yet. Hopefully I'll get there in the next few days?
From there, I decided that maybe my C code was just faulty, so I switched to using the Arduino IDE. Nothing changed, which is what I'd logically expect since I was doing the same thing.
On a different note, I was getting some inconsistent behavior (the rc=-1 error) while I was trying to program a previously functional board (one of Neil's designs) with my previously functional FabISP. I think the most likely explanation for this may lie in the FabFTDI board that I've been using. Because at the time that I made the board, the EECS shop didn't have 8MHz or 16MHz resonators stocked, I found a non-surface mount 16MHz crystal resonator. Based on other schematics that I've seen, it looks like the leads from crystals should go to capacitors and then to ground, which is a setup I don't have, because the board was laid out with a resonator in mind. I don't know that this would actually cause the issue that I was seeing. But maybe? Anyways, we have 16MHz resonators now, so I should swap out (or just remake) the board with one of those.
I'm going to need to spend more time on this. Here's a photo which communicates nothing of any use!