EmonPi temperature sensor fault

I moved a temperature probe attached to an emonPi in my Office yesterday (from hanging out of a cupboard to being inserted through a drilled hole to make it neater), and it appears that it is now reporting Fahrenheit instead of Celsius. Where would I change this back again? I have looked within emonCMS / Admin, but can’t see anything relevant.

I pushed the probe through sufficiently far that all of the metal end & a short piece of the black rubber is within the room. NB: Ignore the units shown in the screenshot !


No it isn’t, I’m afraid. 85 °C is an error - it means that the sensor has been powered but not asked to “convert” the temperature (take a reading), and the reading has been fetched by the emonPi. 85 °C is the power-up value. So I would imagine that in moving the sensor, you’ve damaged one of the connections.

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Oops - that is embarrassing. I think I have a spare one, but if not I’ll have to replace it. Will try jiggling some wires tomorrow…

Thanks @Robert.Wall !

If you have some appropriately-sized heat-shrink tubing, it’s probably worth carefully slicing it off to check. Although my money would be on the fault being at the end you were manipulating, it’s probably easier to check the RJ45 end first, and re-crimp it if you have the appropriate tool (I’ve had one of those not making contact - not having the tool, I used the back of a knife blade to force each of the contacts fully down).

I can’t warn you what to expect at the sensor end, I’ve never looked. I’d expect a TO-92 sensor with soldered connections in silicone grease to give good thermal contact with the case. If you’re not expecting something like that, it could be messy.

Thanks again, @Robert.Wall - I jiggled both ends and now it works. Had this happened when it wasn’t so hot I wouldn’t have assumed it was a DegC / DegF issue. But happy now!

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