ShiftPlusOne
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Re: PoE HAT - USB Ports not working - over-current

Tue Aug 28, 2018 10:43 am

Would somebody who's seeing the problem be able to take a couple of photos of the pi while it's happening? Specifically a side on view from HDMI connector side to see how the HAT sits on the pi would be helpful.

Edit: No longer needed

martinrowan
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Re: PoE HAT - USB Ports not working - over-current

Tue Aug 28, 2018 6:27 pm

Does that mean that the Engineering team have managed to reproduce the issue? Or that they have just ruled out basic contact/interference between the hat and some element of the board beneath?

ShiftPlusOne
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Re: PoE HAT - USB Ports not working - over-current

Wed Aug 29, 2018 4:28 pm

martinrowan wrote:
Tue Aug 28, 2018 6:27 pm
Does that mean that the Engineering team have managed to reproduce the issue? Or that they have just ruled out basic contact/interference between the hat and some element of the board beneath?
There was a suspicion that people may have been not using the provided spacers and pressing the board down such that the transformer was shorting some of the components near the USB chip. However, another component seems to bump up against the audio jack before the transformer is low enough.

martinrowan
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Re: PoE HAT - USB Ports not working - over-current

Wed Aug 29, 2018 4:53 pm

Ah ok, no I'm using the spacers and clearance looks fine. With your comment in mind I also removed the screws and spacers to see if a) raising the board height slightly made any difference, b) That the metal spacers and screws weren't causing the issue. Sadly the issue still persisted.

Stuart-JW
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Re: PoE HAT - USB Ports not working - over-current

Wed Aug 29, 2018 11:44 pm

i used the spacers provided, my pi poe hat lasted a week before giving over current issues. back using the splitter as there is no issues with that. it also developed a strange whining sound.

piman314
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Re: PoE HAT - USB Ports not working - over-current

Thu Aug 30, 2018 3:06 pm

I've just had a powered external hard disc booted off my pi in the middle of a big copy with "over-current change" reports in syslog. Annoying. I'll do some switching around later to see if I can narrow it down as I have two new Pis and two PoE hats to play with.

martinrowan
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Re: PoE HAT - USB Ports not working - over-current

Thu Aug 30, 2018 3:15 pm

My 3rd PoE-HAT has arrived, and as before fails in the same way. I'd love to hear that anyone has been able to use his HAT reliably with USB devices connected, just to see if we can help identify any differences.

piman314
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Re: PoE HAT - USB Ports not working - over-current

Thu Aug 30, 2018 7:15 pm

After getting "over-current change" errors on the first pi when copying from the SD card to an external *powered* disc, I tried it again on different hardware. On the second Pi and PoE hat (I have two new Pis and two new PoE hats) I first tried copying the root filesystem (rsync -ax / /mnt/test/rootcopy) from SD card to the same external powered hard disc, no problem.

So I then added a second USB flash card, mounted that, and tried copying from the external powered disc to the USB flash card, as soon as it started I got the "over-current change" error and the copy was aborted and discs hard-unmounted leading to journal checking.

I then disabled PoE on the switch, plugged the Pi in to a USB power supply, and repeated the failed two-disc copy, this worked fine.

I then unplugged the USB power supply, re-enabled PoE on the switch, set it to "high power priority" which I didn't think would help (it only covers what the switch does when it's overloaded, which it isn't), this time it failed with over-current change errors as soon as I mounted the second USB flash drive, before I'd even started any copying.

With both discs mounted, the PoE switch says the Pi is drawing 4W, about a third of what the PoE hat is supposed to deliver, but I have two separate Pis and two separate PoE hats, all being unable to provide enough power for basic USB data transfer unless I deliver power through either a standard USB power supply, or one of the various 802.3af PoE power splitters I already have. Looks like it's time to fish out the splitters again because this hat isn't working at the moment!

Does anyone from RPI have any suggestions on what can be done here?

The switch is a Netgear "GS724TPv2 ProSAFE 24-Port Gigabit Smart Managed Switch with PoE+" which has powered a small variety of PoE gear and splitters without any trouble so far, although the Pi also seemed to work at first, until I tried to plug things into USB.

aduvenhage
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Re: PoE HAT - USB Ports not working - over-current

Fri Aug 31, 2018 8:47 am

I'm having a similar issue with my new Pi3B+ and the POE-Hat.

I'm trying to power a RTL-SDR dongle, but the USB keeps on switching off -- I do not get over current messages from the PI when this occurs, though. On POE the PI could be running fine for a while, then suddenly start with USB power issues, the recover again. The PI and LAN stays up, even while the USB is having power issues.

I have tried different combinations op powering the pi, but:

- Powered through USB always works
- Powered through POE works very unreliably (USB just switches off at random intervals -- switching off and on the whole time)

I have been measuring the USB current and PI 5V line voltage. The current to the dongle stays way below 500mA and the PI 5V line voltage stays above 5V, normally 5.1V or 5.2V. Even when the USB start having power issues, the 5V line stays above 5V (measured with my multimeter).

Could the PI Hat switching supply be unstable? I have noticed that if I fit a Capacitor (470uF) between ground and the 5V line, the USB issues occur less frequently... Is there anything that could be switching the USB controller off if there is noise on the power input (from the POE regulator).

timothee
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Re: PoE HAT - USB Ports not working - over-current

Fri Aug 31, 2018 9:52 pm

Count me in...having the same stability issues with powering a RPi 3B+ with PoE hat, attached to a Ubiquiti Unifi 16P 150W PoE switch. It's booting and running Raspbian from a Sandisk Ultra Fit USB stick, so unusable with this configuration.

sternj
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Re: PoE HAT - USB Ports not working - over-current

Sat Sep 01, 2018 9:26 pm

I'm also having this issue with a new RPi 3B+ running Hass.io (home assistant). My USB Z-Wave stick works fine when the RPi is powered via the micro usb port, but I'm getting RF/comms/unexpected data errors when powering via the PoE hat. If it matters, the hat is being powered by a Ubiquiti Unifi PoE switch and is making whining noises.

johnboiles
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Re: PoE HAT - USB Ports not working - over-current

Sun Sep 02, 2018 6:11 am

Experiencing the same `over-current change` issue here. I'm using a Pi3B+ with POE hat (ordered via pishop.us -- just started using it today) with a Ubiquiti US-8-60W-US switch. I'm running a z-wave stick and an rtl-sdr on the usb and they disconnect every minute or two. The same Pi and USB configuration has run reliably on USB power since ~April (when I received my Pi3B+). Bummer!

The_Raven
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Re: PoE HAT - USB Ports not working - over-current

Mon Sep 03, 2018 10:01 am

First i have to say: I am VERY DISAPPOINTED!
After such a long time of waiting, this USB issue! :evil:

Second i have to say:
We investigate some time and isolated the problem. :mrgreen:
ATM i can say it is definitively a hardware problem! :o
More infos when we are 100% sure and have a solution.
Then you can buy it :lol:
Just a joke ;)

aduvenhage
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Re: PoE HAT - USB Ports not working - over-current

Mon Sep 03, 2018 12:10 pm

Is there a way to force the USB ports to stay on (i.e. control it through software) on the 3B+? I'm still struggling with the POE Hat and Pi3B+ USB switching off..

I can force power to the USB (while running off POE Hat), by plugging a micro usb cable between the pi power plug and one of its usb ports (i.e. reverse powering the usb ports from the pi power connector). Not sure if this is safe, but it keeps the usb dongles powered. This does not however solve the problem since, the USB ports seem to still stop functioning intermittently? Testing with something like 'rtl_adsb' would just give random USB device errors and disconnects -- exactly like when just powering via POE Hat.

The USB voltage level stays above 5V, so I do not believe it is a supply issue. It also seems that the USB ports are now powered differently (controlled by software?). I have ordered a separate POE splitter to test with and maybe I will just have to use that for my project.

No luck with official POE Hat so far :-(

martinrowan
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Re: PoE HAT - USB Ports not working - over-current

Mon Sep 03, 2018 7:20 pm

Not sure if this is useful information or not. I noticed that the rpi_poe_fan driver had been updated, so performing an rpi-update updated my RPi to rpi_poe_fan module and kernel to 4.14.67-v7+

Since performing that update the dmesg logs are now constantly filling with over-current warnings, without anything connected at all:

Code: Select all

[  174.227110] usb 1-1-port2: over-current change
[  174.317138] usb 1-1.1-port2: over-current change
[  174.467087] usb 1-1-port3: over-current change
[  174.557087] usb 1-1.1-port3: over-current change
[  174.707084] usb 1-1-port4: over-current change
[  174.797088] usb 1-1.1-port2: over-current change
[  174.947087] usb 1-1-port2: over-current change
[  175.037062] usb 1-1.1-port3: over-current change
[  175.187083] usb 1-1-port3: over-current change
[  175.859303] usb 1-1-port2: over-current change
[  175.954295] usb 1-1.1-port2: over-current change
[  176.096980] usb 1-1-port3: over-current change
[  176.186969] usb 1-1.1-port3: over-current change
[  176.336916] usb 1-1-port3: over-current condition
[  176.337052] usb 1-1-port4: over-current change
Deleting the log files, and then checking their size after 10mins of uptime showed the files as:
  • kern.log - 400K
  • messages - 397K
  • syslog - 427K
Hmm, best not leave this running before it fills up the entire 64GB card, or just wears it out!

The_Raven
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 7:05 am

Ok, not so easy to solve the problem.
Also not easy for me to describe the problem because english is not my native language.
But i give it a try:
The problem happens only if the Pi is close to the POE-Hat. If you separate the HAT from the Pi (with long cables for example) the problem is solved. This means the HAT disturbs the Pi. The question is why and how we can solve it.

martinrowan
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 7:30 am

Interesting observation @The_Raven. Suggesting this is some sort of RFI issue, how far away have you moved the PoE HAT from the RPi? For example have you just raised it up ~1cm with extensions to the headers, or did you move it to the end of a 40way cable + extra connections for the 4 PoE specific headers on the RPi?

The_Raven
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 7:56 am

You have to move it far away (end of a 40pin cable and separate PoE-Cable). We have also tried to build a shield (like seen on TV-Tuners). But without success.
And we have seen that there are missing electronic components on the Hat. For example it is recommended to put a 47uf and a 2,2uf capacitor. But on the Hat it is only a 10uf. Maybe this causes RFI-Problems?
Time is short ATM, but i will search for a solution ASAP.
Attachments
POE-Hat.jpeg
POE-Hat.jpeg (208.71 KiB) Viewed 1247 times

aduvenhage
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 9:07 am

Yip, I also confirmed that removing the hat and connecting it with wires, made it work much better.
I connected 5V, 3V, GND, SDA0, SCL0 and the POE pins with wires and it works perfectly now.

I tested again with shielding between the transformer and the little chip beneath it (with hat on header again), but still not working.

Is there maybe an error on the POE Hat board? Like another header pin connected where it should not be?

martinrowan
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 9:10 am

Would be good to see if anyone has a 40pin ribbon cable could attack all the GPIO pins + the 4pins for the PoE Header. This would determine if there was something being misconfigured on the rest of the GPIO header. I can't do this till I get home from work, and will post results then if nobody else gets there first.

The_Raven
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 9:31 am

The picture is from my "first attempt". So maybe it was wrong to post it because it "confuses". We also tested it with all 40 pins connected trough a IDE-Cable and it works!
Then we tested it with a short IDE cable (3cm) and it has NOT worked. Then we cut pin for pin beginning from the gpio side. And with every cuted pin it has worked better.
We tested it also with only the power-pins connected (short version) and it works sometimes but is very buggy.
With long wires -> No problem (and i think this was not only luck, think i can confirm it).
I stay by my statement: It looks like a hardware problem.

Hint: Take a look in the schematics from MP8007 datasheet.

martinrowan
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 9:43 am

Thanks for all your work @The_Raven. Is it the physical distance that makes the difference, for example with long leads/wires attached if you move it close to the RPi does it start to fail. Or is it the length/resistance of the cables that are making a difference? I'm assuming it's physical proximity.

Really hope the Engineering team are catching up on this thread and will come back with a response soon. Seems like a pretty fundamental issue we're all facing.

jamesh
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 11:01 am

martinrowan wrote:
Tue Sep 04, 2018 9:43 am
Thanks for all your work @The_Raven. Is it the physical distance that makes the difference, for example with long leads/wires attached if you move it close to the RPi does it start to fail. Or is it the length/resistance of the cables that are making a difference? I'm assuming it's physical proximity.

Really hope the Engineering team are catching up on this thread and will come back with a response soon. Seems like a pretty fundamental issue we're all facing.
Yes, this thread is being followed.
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hippy
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 11:02 am

Another test worth trying, though it means modifying the board and having to do some reverse engineering as there are no circuit diagrams or board layouts available, is to isolate the PoE and fan parts of the circuit.

That would help determine if the problem lies solely with the PoE or fan part.

nightwatchman
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Re: PoE HAT - USB Ports not working - over-current

Tue Sep 04, 2018 11:29 am

An interesting set of replies!

However, in the meantime I am going to send my PoE Hat's back to RS before my 30 days runs out; my 2 PoE hats have just been sitting on my shelf looking like pretty paperweights.

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