Pi Undervoltage/power issues: I had a strange lightning bolt/temperature symbol with an exclamation mark popup in my navbar, what does that mean?

Are you measuring the voltage from one of the two 5V GPIO pins to any ground pin while it's running?

It would be nice to know which Raspi we're talking about.

You may be onto something about using the micro USB port versus powering it via GPIO. I remember that Robo 3D got in a batch of Raspberry Pi 3B computers which had sloppy micro USB connectors, the plug never could get a tight fit and the 5V would make/break as a result. (Testing this then, hold the micro USB plug firmly in place with rubber bands and see if the problem goes away.) If you find that it's the loose micro USB connector, consider adding a slight crimp in the connector housing with a pair of needle-nosed pliers or powering it differently.

That doesn't mean it isn't getting temporary undervoltage- you can check the flags on vcgencmd to see if it is "now" vs "in the past". Measuring undervoltage independently- but if you are getting the flag, you have power problems.

hello, I am having throttling issues with under voltage at some specific times. I only find the UI confusing and not very practical. It would be better if the icon only appeared when there is a current issue going on and then time out after like 5 mins or manually set. I get my setup is not ideal, but is not bad either. I don't want to disable the icon so I can keep my interface neat, but how it is really encourages me to do so. Thanks for the time.

See if you can find a 5.2V 3A power adapter and the problem might go away for good.

I have one of 2,5A which gives a steady 4.96 V... it is where I need it to be and I am just seeing under voltage occur right at startup. I'm guessing it is not so fast to provide 2.5 amps from zero, maybe small caps? anyhow, I don't believe spending that money when my powersource which was kinda expensive works fine after booting. I believe that a timeout feature will make the alert much more useful on the long run. Specially if it is acompanied by a notification banner.

I've been printing for a couple years now and from Day 1 I plugged it into an APC brand UPS (I know, this sounds like a commercial). For many people, the problem starts at the wall (the wall voltage occasionally drops below some arbitrary threshold). And then the output side of the Raspi adapter is lower than what it is supposed to be (which then gets reported as < 4.64VDC).

So, begin at the wall and use a multimeter and sit there and watch it while opening your refrigerator door. The compressor then will kick in which wants lots of power and will drive the input voltage down to something ridiculous like 109VAC.

Seems to make sense. But still that would mean im stuck with this behavior. Im a student and built my printer from literally scrap, can't afford a UPS since it would probably end up costing up to half my printer total cost! haha
If the timeout was added, alongside with a banner notification upon new under voltages; it would make this feature so much more useful for people like me on a far from ideal setup.

Well, that's not really my decision since I didn't code OctoPrint.

What I do, though, is I buy used APC UPSs at flea markets or someone's garage sale. They're heavy since they include a 12V acid battery inside like you might find in a car so anyone is delighted to get rid of them for almost nothing (even free).

At about the five-year point, the battery needs to be replaced but you can get them locally for about $24 but they'll give you about $5 back as a core fee for the replacement battery you bring back to them. Replacing the battery is about the easiest thing you've ever done.

From time to time I get the grey undervoltage symbol despite the Pi is powered by a PC PS at about 5.4V.
Is this occurrence of the undervoltage logged somewhere? I assume in the octoprint.log, yes?

Yes. It should log any kind of detection events in there. I think it also logs when everything is normal again.

Thank you! I'll check after the running print job when and why it occurred...

For this issue also occurred in idle mode, I further investigated and found a quite bad connection within my "Power Supply & OctoPrint Unit".
"Problem erkannt - Problem gebannt" :sunglasses:

Is there any possibilities how to reset this symbol without rebooting during printing (to check if show again) or show history when happen this problem and when missing?

The history of these events will be in both the octoprint.log as well as the /var/log/syslog if you were interested in seeing them.

The existence of any undervoltage condition puts your microSD card's second partition at risk for corruption as well as serial-related problems, etc. The duration of each event would further be a factor. Note that this doesn't tell you how much under 4.64VDC the input voltage dropped, just that it did so. And yet, this is also a factor. Behind-the-scenes, there is a magic voltage that indicates the threshold between a digital zero and a digital one on the 3.3V data logic lines. The lower the input voltage, the more likely that bad decisions will be made internally by the Pi.

cat /var/log/syslog | grep oltage

Sep  1 06:25:07 raspberrypi kernel: [3316534.286203] Voltage normalised (0x00000000)
Sep  1 07:05:03 raspberrypi kernel: [3318930.470847] Under-voltage detected! (0x00050005)
Sep  1 07:05:08 raspberrypi kernel: [3318934.630893] Voltage normalised (0x00000000)
Sep  1 07:08:58 raspberrypi kernel: [3319165.512990] Under-voltage detected! (0x00050005)
Sep  1 07:09:03 raspberrypi kernel: [3319169.672947] Voltage normalised (0x00000000)
Sep  1 07:09:11 raspberrypi kernel: [3319177.993172] Under-voltage detected! (0x00050005)
Sep  1 07:09:17 raspberrypi kernel: [3319184.233224] Voltage normalised (0x00000000)
Sep  1 07:09:23 raspberrypi kernel: [3319190.473113] Under-voltage detected! (0x00050005)
Sep  1 07:09:28 raspberrypi kernel: [3319194.633162] Voltage normalised (0x00000000)
Sep  1 07:10:18 raspberrypi kernel: [3319244.553560] Under-voltage detected! (0x00050005)
Sep  1 07:10:32 raspberrypi kernel: [3319259.113651] Voltage normalised (0x00000000)

Thanks for explanation
My problem its not undervoltage but overheating
I´m interesting how to reset this overheating symbol in navbar during printing over SSH or other way?
For checking of syslog is possible to use grep heat?


You can't. The symbols rely on what vcgencmd get_throttled reports back, and that reports past event since last boot. AFAIK there's no way to change that.

Check the logs if you need a history, as @OutsourcedGuru pointed out it's all in there.

Also: if this symbol appears often or always, there is really an issue with the power supply/overheating that should be removed.

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I wish they would turn this feature off. It is annoying and isn't accurate. I have a very good 5 volt 4 amp supply going to it and this still comes on. I have used the power supply that you buy with the Pi, still comes on. I don't trust it. I have been seeing this icon for years with no issues.

I think it's very accurate. Since I removed a bad connection in my setup, I never hat that symbol again.
Do you connect power via USB port or directly to the GPIO. Do you have some devices to the PI's USB ports that draw some more current. Have you checked the voltage beyond the USB port?

I have 4 of these running octoprint servers. I use the port dedicated for the power supply. The only things connected are the printer (which supplies its own power) and a webcam. All 4 units show this symbol, using larger power supplies or the ones sold for the Pi. I have had the symbol show up with nothing plugged into it...using the power supply sent with the unit.