Well, the whole thing failed to boot tonight so retrieved it, but basically seems to me the air-quality subsection failed, shorted or something, was basically reading in the 12 million range (maxing out) when normally in the 100 thousand range… temp, humidity and barometric pressure all still OK.
so a bit of corrosion on the pi zero’s micro usb ports… aluminium connected to power eh! otherwise looks incredibly clean inside, no signs of water ingress, so was a cool openscad 3d-print design I did, if I say so myself…
anyway back up soonish….