There were some bad copper bridges on the daughterboard from the “fuzzy” area spotted by someone at the PCB making demo. (I suspect it was a small bit of crud holding the artwork away from the board.) I opened those bridges with a combination of Dremel and Exacto knife. There were also some small bridges on the main board. That’s quite unusual – my processes almost always produce clean boards. Anyway, those are cleaned up as well. Boards are a little ugly, but should be functional.
The daughter board is drilled, the 28 pin socket soldered in, and I found some suitable pins (pulled from an old wire wrap board, I think) for connecting it to the main board and soldered them in. I think the daughterboard is ready to go.
The main drilling run for sockets, most components, clip leads to the cells and pins (both to daughter and to Arduino) is done. I still need to drill some bigger holes for the binding posts for the load resistor and the larger cables for the main discharge current.
A significant remaining task is figuring out what I’m going to do about hacking an extra 4 switches on to the (main) board for discharge current and overall voltage measurement. I’ve drilled a couple of additional holes for jumpers for control signals and analog signal to the same analog input the cell measurements use, plus power and ground. I’ll also need the voltage divider resistors and some kind of socket for the yet-to-be-specified IC. Might well be another small board glued on top of the main board. In any event, I probably shouldn’t mount the daughter until I have these still-open design issues resolved. 🙁
Pictures needed, too.