Knob stops updating

I’m currently using read only knobs to display some values on my panel. Every once in a while, some random knob stops updating. This time is was the one for the extruder temp of my 3D printer. I added a dummy widget for testing and that keeps updating just fine. Browser console doesn’t show any errors, neither does openhab.log.

Any ideas on what could cause that or where to start debugging?

Look at events.log to verify whether the problem is that HABPanel is not updating or whether the Item is not being updated is the first step.

Thanks :). But as I wrote and as (kinda) can be seen on the screenshot, a dummy widget with the same item source updates just fine :). event.log was of course my first look. After that I added the dummy widget.

Weird, never seen the knob widget fail to update. :confused:
Open the browser’s developer tools (F12) and check for related errors (in red) in the Console, maybe it received an invalid value and stops functioning?

:frowning: :frowning: :frowning:

Right, sorry.

Once it stops working it won’t work again until you refresh the page?
Or what if you go to another dashboard and go back?
Does a slider work?

Sliders work as far as I use them yet but I noticed a delay in updating when I change a dimmer e.g. from my phone.
Changing between panels doesn’t seem to do anything.
When I use the HABPanel reload function, I see no changes.
When I use the browser reload, the page reloads, the knobs first show the value with one decimal, then they switch to value without decimal (sometimes the one which gets stuck, gets stuck already there) and then one knob (usually one of the temperature knobs) gets stuck and doesn’t update any more.

Ok thanks I’ll try to reproduce but it could be tricky…

If you need any more info, let me know. The item sources are mqtt messages from an octoprint instance which is fairly chatty. Could it be that it’s just sending info too fast?

That’s the items:

Number  OPprogress      {mqtt="<[broker:octoprint/progress/printing:state:JSONPATH($.progress)"}
Number  OPtempBed       {mqtt="<[broker:octoprint/temperature/bed:state:JSONPATH($.actual)"}
Number  OPtempBedT      {mqtt="<[broker:octoprint/temperature/bed:state:JSONPATH($.target)"}
Number  OPtempExtr      {mqtt="<[broker:octoprint/temperature/tool0:state:JSONPATH($.actual)"}
Number  OPtempExtrT     {mqtt="<[broker:octoprint/temperature/tool0:state:JSONPATH($.target)"}

Long time lurker, having learnt much via these forums.

@anon69363600, did you figure this out?

I’ve used a knob widget to display the wattage of some appliances - it looks great, but stops updating. I thought it was the smart switch at fault to begin with, but the slider widget works quite reliably. No errors in either the openhab or console log. Again - refreshing the panel resolves it (temporarily).

@ysc - I think I have been reliably able to replicate.

Here is my test scenario. A knob control, driven by an Aeotec smart plug; the item in question is reading the current wattage. Here I have a knob control, with a slider of the same item immediately below.

The slider moves up and down periodically as power consumption changes. The knob control displays correctly at the beginning. If the power draw drops, this is correctly indicated by both the slider and the knob. If the power draw increases, it’s indicated correctly by both - but at this point the knob control also becomes stuck at the higher value and remains there unless I hit the browser refresh button.

As the slider is editable (the knob widget is not), I replicated the scenario by dragging it up and down and observing the result. The correct wattage is then applied around 1s after my manual adjustment - with the slider moving to the correct value every time and the knob only updating according to the detail I’ve provided above.

Checked the console of the browser - I can see the item being updated to new values; when I apply a manual edit to the value I can also see a command being sent to the item. Also checked openhab.log; nothing there at all when I either manually update the value or refresh the browser.

If there’s a debug log I can apply to either openhab or the browser that would apply to habpanel, I’d be happy to collect it.

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