PoE HAT - USB Ports not working - over-current (FIXED - New Hardware Release)

[sammaye]

I too am experiencing an interesting problem with the PoE hat and I am not sure if it has been listed yet.

I have a Pi 3 b+ and if I plug in a pen drive on its own it won't work, it doesn't send the right power, but if I plug in a pen drive with keyboard and mouse or even just pen drive on a USB hub (not powered by mains) it works, but on its own it is almost like the Pi firmware cannot see the amount of the power it needs to power the drive correctly.

Very weird...

[weust]

Yeah, that's what the previous 6 pages in this topic are about...

[melbeckman]

Regarding the four-pin connector breaking: One thing I’ve noticed in many demo videos is after unboxing the user, in their excitement, skips installing the standoff’s and plugs the board righ onto the pi as far as it will go, nice and tight. This pushes the pins far deeper into their sockets than the designers apparently instened. The instructions state clearly “you mus install the supplied standoff”. It’s possible the boards make bad electrical contact when pressed together too far, or it could just be that the connectors will require too much force to separate.

I hate to say it, but RTFM.

[rasporg]

I bought one and have still not fitted it due to several problems with it.

Besides the design problems electronical and four-pin connector I was puzzled about the distance poles. I can't use them because the RaspberryPI is screwed down in it's casing.

I had expected more flexible distance poles that are on the bottom wider to fit over screws or locking pins. Maybe make them of plastic.

I am thinking of returning it and get my money back. I have been always been impressed by Raspberry but I am really not impressed with the PoE Hat.

[sammaye]

That's not even RTFM, since there is no manual, it is just considered common sense that you stand it off with the provided screws, which... Well, TBH it should be. As for cases, get a case that doesn't indent on the inside, there are a few out there, like https://www.amazon.co.uk/gp/product/B01 ... UTF8&psc=1 and you're set, I am a complete noob to Pi, so noob I had never even looked at one before last week, but even I figured this out with ease.

[Roken]

Sometimes. the problem is on the other side of the keyboard. Sigh!

[hippy]

I was puzzled about the distance poles. I can't use them because the RaspberryPI is screwed down in it's casing.

It does seem there wasn't a lot of consideration given to those who have cases a Pi secures to using screws or bolts.

There are seven options I can think of being in the same situation as yourself -

Find or create hollow stand-offs and use longer bolts to secure through the PoE HAT, through the stand-offs and through the Pi. That's probably the easiest solution. You can DIY create hollow stand-offs by cutting old pens to size or even pulling or drilling the lead out of pencils.

Find stand-offs which can screw into the case instead of the screws you are currently using, and attach the PoE HAT with nuts if threaded at both ends or a bolt if tapped. Many such stand-offs are metal so check that won't cause any shorts first if using those.

Drill out the holes the Pi screws into so longer bolts can be passed through from the outside, through the Pi and into the stand-offs. You might have to countersink the exterior holes to reduce head height. How easy and safe it is to do that would depend on the case.

As above but using your own hollow stand-offs with long bolts which can pass through everything and simply secure the PoE HAT with nuts.

Construct your own sideways-U stand-offs so the current bolts also screw through the Pi end and use a nut and bolt or self-tapping screw to secure the PoE HAT. I haven't checked how feasible that would be.

Construct something similar which can be fitted alongside the Pi to hold the PoE HAT in place. The practicality of that will depend on the case being used. It's rather unfortunate that access is usually required along all three sides of the Pi where such a thing would be best fitted so that might require some thought.

Or similar by just gluing or bolting a shelf or ledge to the case interior which supports the PoE HAT.

[jamesh]

I was puzzled about the distance poles. I can't use them because the RaspberryPI is screwed down in it's casing.

It does seem there wasn't a lot of consideration given to those who have cases a Pi secures to using screws or bolts.

There is a limit to how many third party cases we can test with. And with only 4 mounting holes there's not huge amount of alternatives.

[hippy]

There is a limit to how many third party cases we can test with. And with only 4 mounting holes there's not huge amount of alternatives.

Indeed, There seems just three ways of securing a Pi in a case I can see; without screws, screws going down, or screws going up. And that last one seems unlikely me to me.

I suspect no one even thought about it. I hadn't until it got mentioned.

I imagine there will need to be some filing done for any cases which don't use screws but put a spigot up through the mounting holes.

[dliloch]

Is there a recommended 48v poe injector for the hat? There are so many out there .. Thanks

[robertloomans]

I imagine there will need to be some filing done for any cases which don't use screws but put a spigot up through the mounting holes.

I have the official case which has those... I just used some side-cutters to clip them off.

[rasporg]

I got this morning an e-mail that the PoE Hat was offered now in combination with the PI 3B+ and went the Approved Reseller and found the warning a bit not being a warning.

802.3af-compatibele POE-injector, switch of router vereist (niet inbegrepen).

maximale stroomsterkte van 200mA naar de USB poorten,

Product Specificaties

Merk: Raspberry Pi
Garantie: 2 jaar

The warning line is the one ending comma and I made it italic. Translated it say's "maximum 200mA supplied to the USB ports,".
It is just dropped in the text. I assume that a Approved Reseller of RaspberryPI should give a better insight of what a user is going to buy.

[hippy]

There seems to be a few (unofficial?) resellers still selling the PoE HAT with the 200mA caveat. I guess they are relying on "we told you, you knew what you were buying" to avoid warranty claims.

It wasn't clear to me that the only problem with the PoE HAT is that it cannot ( in some cases ) deliver more than 200mA to the USB ports and could be sold and used with that caveat applied.

Members have reported other problem which may be PoE HAT related and last official news I have seen is that a hold was put on sales while they investigate and get to grips with the issue.

Maybe there needs to be an update or some clarification from the RPF. The official product page is still showing it as "coming soon".

https://www.raspberrypi.org/products/poe-hat/

No sign of any explanatory blog post yet but I guess that is on hold while the issue is being fully resolved.

[jamesh]

There seems to be a few (unofficial?) resellers still selling the PoE HAT with the 200mA caveat. I guess they are relying on "we told you, you knew what you were buying" to avoid warranty claims.

It wasn't clear to me that the only problem with the PoE HAT is that it cannot ( in some cases ) deliver more than 200mA to the USB ports and could be sold and used with that caveat applied.

Members have reported other problem which may be PoE HAT related and last official news I have seen is that a hold was put on sales while they investigate and get to grips with the issue.

Maybe there needs to be an update or some clarification from the RPF. The official product page is still showing it as "coming soon".

https://www.raspberrypi.org/products/poe-hat/

No sign of any explanatory blog post yet but I guess that is on hold while the issue is being fully resolved.

It's not clear yet. Some combinations of pi and Poe have something weird going on and wexare still investigating.

[Juggler00]

I’m beginning to wonder if there isn’t something wrong with Model 3 B+. I’ve tried the Adafruit PoE splitter (https://www.adafruit.com/product/3785); I cannot get the Pi to boot.

Has anyone found a PoE injector that actually works with the 3B+?

[enigma1406]

I’m beginning to wonder if there isn’t something wrong with Model 3 B+. I’ve tried the Adafruit PoE splitter (https://www.adafruit.com/product/3785); I cannot get the Pi to boot.

Has anyone found a PoE injector that actually works with the 3B+?

What do you mean by works? With the POE hat I can get my 3B+ to boot and it works from that perspective. In my case, the only issue is that it constantly throws an undervoltage warning. No issues with performance, temperatures or stability.

[Brasse83]

I’m beginning to wonder if there isn’t something wrong with Model 3 B+. I’ve tried the Adafruit PoE splitter (https://www.adafruit.com/product/3785); I cannot get the Pi to boot.

Has anyone found a PoE injector that actually works with the 3B+?

I use the same exact one for my 3B+, and works just fine. And that is a unit on which the official PoE hat will not work.

[rayC]

I am also having problems using the POE HAT with a USB barcode hand scanner, every couple of minutes it locks up, I'm assuming due to lack of power.
Out of interest I went to the RS Components page and the listing for the POE HAT is now gone, I'm assuming they know about issues and have stopped selling this HAT.
Hopefully issues will be resolved and an updated version released. I'm just glad I only bought a couple of these to test and not the couple of dozen I intended to.

[techrep]

James,

I have a mode 3 B+ recently received from Newark / Farnell that will not boot with the PoE hat installed. Network is all Ubiquity and the switch feeding the Pi is a Unifi 8 pport, 150 watt switch (https://www.ubnt.com/unifi-switching/un ... ch-8-150w/ ) in either the 'auto' or 'manual' configuration.

in addition I cannot get it to boot with even the most robust USB power supply I have on hand. I do see the rainbow square but the lightning bolt in the upper left is always on.

My last attempt to get it to boot today will be lashing it up to my bench supply and limiting the current to about 3 amps or so and seeing if I can get it to boot like that. I'll report back on the results. If I let the smoke out then so be it but if that eventuality comes to pass would you like the device for forensic engineering and analysis? Do let me know.

Regards,
Chris

[rpdom]

I cannot get it to boot with even the most robust USB power supply I have on hand. I do see the rainbow square but the lightning bolt in the upper left is always on.

This sounds like your microSD card has old bootcode on it that doesn't support the 3B+ The lightning bolt low-power warning is a classic symptom on this. Make sure you have a fully up to date Raspbian Stretch image on your card.

[rprade]

I am having problems with all 5 POE hats purchased from Newark a couple of weeks ago. All of them are used to connect a USB Z-Wave controller over Ethernet and are dropping connections. The same boards work fine with an external power supply or POE adapter.

Reading through this thread it seems this is a known problem and as yet is unresolved. Is that correct?

[rprade]

Reading an interview with Eben Upton, he states: "Removing reservoir caps from the main board" as a solution. Even though it limits "hotpluggability" it would still be a good solution for my purpose.

Is there a post somewhere showing this modification?

[jamesh]

I am having problems with all 5 POE hats purchased from Newark a couple of weeks ago. All of them are used to connect a USB Z-Wave controller over Ethernet and are dropping connections. The same boards work fine with an external power supply or POE adapter.

Reading through this thread it seems this is a known problem and as yet is unresolved. Is that correct?

Can you email [email protected] FAO James Hughes with details of the issues you are seeing?

[rprade]

I am having problems with all 5 POE hats purchased from Newark a couple of weeks ago. All of them are used to connect a USB Z-Wave controller over Ethernet and are dropping connections. The same boards work fine with an external power supply or POE adapter.

Reading through this thread it seems this is a known problem and as yet is unresolved. Is that correct?

Can you email [email protected] FAO James Hughes with details of the issues you are seeing?

Done!

James Hughes;

I was asked to share this with you by jamesh on the raspberrypi.org forums.

I ordered and received 5 POE hats from Newark a couple of weeks ago. These are to be used with Pi 3 B+ boards as an IP to serial interface for USB Z-Wave controllers. Basically, they just run ser2net. With the POE hat installed, they drop connections (to the USB device, not IP) every 2-20 minutes. If I use an external POE adaptor as I was with Pi 3 B boards, this is all stable and reliable. If I use a GPIO Z-Wave controller, the Pi 3 B+ with the POE hat is also stable and reliable.

[techrep]

This sounds like your microSD card has old bootcode on it that doesn't support the 3B+ The lightning bolt low-power warning is a classic symptom on this. Make sure you have a fully up to date Raspbian Stretch image on your card.

Put the latest version on SD and booted. I get past the rainbow cube but still get the lightning bolt. I took it to the bench and lashed up a programmable power supply to a random USB cable I had sitting around. In addition I have a Dell USB keyboard & mouse that is tied to the Pi using Dell's universal USB receiver. I imagine that puts more than a few milliamps of load on the Pi's USB supply.

I power up the Pi and monitor the boot sequence using an external HDMI monitor. If I set the external power supply to 4.9 volts and start the process I'll see an overcurrent message in the boot messages that fly by. If I increment the power supply voltage by .1 (100mV) and observe the same sequence I will see a clean boot sequence in the messages at 5.0v but will still see seemingly random flashes of the lightning bolt.

What I have done is exercised the Pi in various configurations and I don't see the lightning bolt go away until approximately 5.3v is applied. I've monitored the output of the supply both at the binding posts and at the Pi proper (test points ground, pins 3,4,5&6 and pin 7 after the polyfuse) and the reading are within a few 10's of millivolts. I chalk this up to the voltage drop presented by the super thin power wires in the junked USB cable I am using.

Long story short is that unless the PoE hat is going to have a very stiff supply with a small handful of overhead voltage we can expect to see this continue.

I'm more than happy to help troubleshoot the issue if somebody is willing to craft a test regime for me to follow.

Alternatively I can send off the kit to JamesH and team as both parts are functionally useless to me in its current state. I say this in a non-pejorative way, sending them back does nothing to further the troubleshooting and only puts a minimal amount of cash back into my pocket.

Please let me know if I can contribute in some way.

-Chris