I had to modify the Relay boards – The relays were getting VERY hot. Turned out to be a fault in the design – the 5V relays were being run from the 12V supply. Simple fix to cut a trace, and run a wire to the output of the on-board 5V supply. I guess that explains why they were $6 a board 🙂
And a quick look at the half-finished Relay driver board! That’s 6 x 74HC255’s and 6x 74HC244’s
Fab work is always ‘interesting’, given the garage is full, so all work gets done out in the carport. Which means lugging whatever tools I need outside as I need them. Today we’re cutting up the Pi carriers, as well as starting on the framework that the Pi’s will actually sit in.
The carriers worked out pretty well. Looks like I’ll get three rows of Pi’s in the case! NICE.
And then starting on the framing. More on that next weekend!
Started work on mounting the Pi’s. Biggest hassle was working out how to supply power, in a way that still makes them nice and modular incase I have a dead pi once it’s sitting in the DC. Can’t very well power off 40 Pi’s to replace one..
I had considered using a bunch of RC power connectors to plug the carrier boards for the Pi’s in. But it ended up being FAR too difficult. Decided to go with the tried and true method of a power cable 😉 It’s going to mean a LOT of ribbon cable though!
Tomorrow, I hope to have the whole carrier framing sorted!