Ralph, Terry: thanks for your comments.
1. All my sensors are mounted on small circuit boards bought from (now
defunct) American company Hobby Boards. I believe the temperature
sensors are powered parasitically, though there is a 5v power injector
to feed a humidity meter.
2. They are connected to the Pi by a DS2490 USB-RG45 bridge, and the
software that drives them is based on the Dallas 1-wire software
implemented by a third-party, which has been in use for 10 years.
3. The second net is completely independent though same set-up, feeding
its data directly to a postgresql database.
4. I see no reason for the values of electrical signals to have changed
unless something has happened to the Pi.
Anyway, this is all a bit moot, since I managed to break one of the
DS1820 leads when examining the board!
So I'll have to wait for a replacement to arrive before investigating
further.
Regards
Graeme
--
Next meeting: BEC, Bournemouth, Tuesday, 2020-01-07 20:00
Check to whom you are replying
Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/
New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
