The first of two plastic cylinders has arrived. This is the 27mm inside-diameter coin collector’s cylinder. The microcontroller just barely fits into it with the battery attached, but the cylinder appears to be a hair over 30mm wide, according to my measuring tape, too wide by about half a millimeter to fit into a carboy. I’ll test for sure on the carboy next time I have a chance.
The 27mm outside diameter cylinders obviously won’t fit the tube, but they’re also 150mm long, and may be able to fit the battery and microcontroller in line, depending on how they can be angled inside. I’ll give that a try when the smaller/longer cylinders get here.
In the event that neither setup works, I have still another idea, involving a modified carboy stopper, a cannibalized Ethernet cable, and a separate sensor float with the microcontroller outside the carboy and only the accelerometer inside. Updates as they come.