Basic Information: pi4 Manta M8P over USB U2Can over USB 6x ebb36 toolhead boards over Canbus. the offending toolhead has PT100 attached to MAX31865 Describe your issue: So I have been noticing occasional temperture sensor spikes to crazy values on klipper restart. In the order of trillions. They…

Indeed, there are a few reports here mentioning the same phenomenon, No idea though, why and where to start looking. Generally I’d doubt that the klippy.log is of much use here except that it confirms that the sensor send some wired values.

Maybe this can help: [image] Heater fault, spurious spikes [SOLVED] I have a 4 wires PT100 (E3D 2 wires modified to 4 wires as per DC42 blog) which works fine but some times I get a random spikes in the temp graph that I am unable to reproduce. Touching and bending the cables does not p…

I’m not aware of reports that Klipper itself is producing erratic temperatures, and it’s not clear to me what in the Klipper code could cause them. As a total guess, it’s possible that the GUI code (eg, mainsail, moonraker, fluidd) is getting confused by a restart and performing some invalid calcul…

[image] Viesturz: 6x ebb36 Interesting, did you present your setup here before?

Thanks for asking, shameless plug: https://github.com/viesturz/tapchanger

[image] Viesturz: This appears like one every 10+ restarts I’m using a lot of temp sensors at work. Sometimes really expensive sensors. My testing environment can be compared with a 3D printer. Lots of noise and spikes in the air. In my working logs also I find some temp readings, which mak…

Looking at the code, the max temp an MAX31865 converter with default settings it can emit temp from -246 to 988 degrees. So suspecting something is off with the UI code or some other buffer.

[image] Viesturz: So suspecting something is off with the UI code or some other buffer. I don’t think so. In my eyes just a wrong reading (due to electrical distortions from the environment) from the sensor or AD conversion error. Just throw that reading away, since you know it must be wrong. …

Hmm, digging deeper, the sensor code passes max value to the spi driver, but that would still provide the raw 32 bit value before detecting that it exceeds max and resetting on fault. Maybe there is something to it, will analyze some more tomorrow.

[image] hcet14: I’m using a lot of temp sensors at work. Sometimes really expensive sensors. My testing environment can be compared with a 3D printer. Lots of noise and spikes in the air. In my working logs also I find some temp readings, which make no sense. When analyzing the logs I just del…

Ebb36 Temp sensor spikes on Klipper restart

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Sineos November 30, 2023, 10:27am 12

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Ebb36 Temp sensor spikes on Klipper restart

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