Initial answer to my own question - I have previously (years back) modified the firmware and uploaded it to support something like 18 DS18B20s, based on some comments and suggestions from a post back in 2020 or earlier. It basically involves a loop based on the number of probes detected and building up a custom payload to be returned - and then modifying emonhub.conf to decode the custom payload.
I’m going to be plowing through the firmware myself so that I can add in/add back the functionality and I’m happy to contribute the code back to the repository, but before I do this . . . has someone already done it and uploaded it somewhere? I reckon there’s a good chance that someone has already solved this and has a working config.
Ugh, second answer to my own question - I see the firmware has a comment to the effect that -
NOTE: If the number of external temperature sensors is changed from 1, the 4 lines below: ‘names = …’,
‘datacodes = …’, ‘scales = …’ & ‘units = …’ must be changed to suit.
The maximum recommended is 4.
I’m going to try that now. Apologies for posting before fully checking, but I didn’t spot that bit.
Thanks very much for sharing that observation, @zag (no need for apologies as far as I am concerned!) - I just came across your post, having also missed that crucial little detail when I was last trying to set this up, only a month or so before you. I can now embark on my long-planned logging of flow and return temperatures across various things…