Announcing the Raspberry Pi PoE+ HAT

Today we’re announcing the next generation of our Power over Ethernet (PoE) HAT. Compared to its predecessor, the Raspberry Pi PoE+ HAT delivers more power, implementing the 802.3at PoE+ standard; and it runs cooler, thanks to various design improvements. Best of all, we’ve been able to keep the original affordable price of $20.

PoE HAT TNG

The current global semiconductor shortage — which you’ll almost certainly have read about by now — is constraining our supply of the original PoE HAT. In general, we’re weathering the shortage very well, and the supply of mainline Raspberry Pi computers, Zeros and our other products have not been affected (we’re very good at pipelining). Unfortunately, the first-gen PoE HAT uses silicon that’s in short supply.

The old HAT will remain in production, but we are taking the unusual step of announcing this new product before we have stock in channel, so that industrial customers can consider migrating to the new PoE+ HAT, which will have shorter lead times. The Raspberry Pi PoE+ HAT will be available from our Approved Resellers in early June. (Visit our Products page to be automatically directed to your local Approved Reseller when you select a product.)

Power (over Ethernet) to the people

One of the coolest features we’ve added to Raspberry Pi in the last few years has been Power over Ethernet (PoE) support. From Raspberry Pi 3B+ onward, we use an Ethernet jack with the appropriate taps on its windings, and connect those taps to an additional 4-pin header, located just beneath the top-right mounting hole. A HAT can pick up these signals, request power from the switch, and regulate the resulting 37-57V DC down to 5V to power the Raspberry Pi.

At the end of 2018, we released the Raspberry Pi PoE HAT, which did just this. After some embarrassing teething troubles, it has become one of our best-selling accessories. We’ve seen it used in industrial applications like digital signage and factory automation, and by hobbyists who want to put their Raspberry Pi somewhere remote, sharing a single cable for both power and data.

More power

The original PoE HAT implements the 802.3af standard, and can deliver a guaranteed minimum of 13W to the Raspberry Pi. This is enough to power a Raspberry Pi 4 at maximum load, but not quite enough to power the hungriest USB peripherals at the same time.

The PoE+ HAT implements the 802.3at standard. When used with a compatible switch or injector this means it can deliver up to 25W, as you can see from this comparison table.

PoE HATPoE+ HAT
Standards supported802.3af802.3af, 802.3at
Output voltage5V5V
Maximum output current2.5A5A
Maximum power15.4W25.5W
FanYesYes
Current senseNoYes
Transformer designWire-woundPlanar
PCB4 layers, 2oz copper4 layers, 2oz copper
Price$20$20
Compatible withRaspberry Pi 3B+, 4BRaspberry Pi 3B+, 4B

A better diode rectifier

What else has changed? To reduce heat dissipation we replaced the diode rectifier with an “ideal diode” rectifier, in the form of a Microchip PD70224ILQ device.

Thermal image of PoE+ HAT delivering 2.5A

A shiny new transformer

PoE implementations require a transformer to provide voltage conversion and isolation. When you think of a transformer, you probably think of wire wrapped around a ferrite core, and this is exactly what the original PoE HAT uses. For the PoE+ HAT, our friends at Bourns have provided us with a shiny new toy: a planar transformer.

Bourns planar transformer

As you can see from this disassembled version, in a planar transformer the “windings” are actually traces on a multi-layer PCB; the ferrite is assembled around the PCB. The result is a slimmer transformer (useful if you really care about z-height and are prepared to dispense with the fan) which is more suitable for surface-mount assembly. And it has the added benefit of looking like an artefact from the future.

Like something off the Starship Enterprise

We think you’ll notice a real improvement over the original and much-loved PoE HAT. We’re always fascinated to learn what work users end up putting their Raspberry Pis and accessories to — if you’re doing something particularly cool with PoE, let us know!

82 comments

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nise …. I love it

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I’ve pre-ordered one to try out. If you intend to use the extra power available then check the power budget of your PoE switch ports can handle it.

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Would I be correct in thinking that as it supports both 802.3af and 802.3at standards it will work still with my existing POE switch which only supports 802.3af ? or would I need to upgrade to POE+

Eben Upton

You’ll be fine. No need to upgrade your switch.

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It will work but still be limited to 15.4W per port, the limit of the switch.
The at standard is 2009 though, so switches that don’t support it are limited to the real budget ones.

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Will it be possible to set a lower POE-class on the hat so that if one has a 802.3at switch with limited resources and one doesn’t need the whole 25W it would still work?

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an electronic device only uses the power it needs. if the hat can provide 25w, but the pi only uses 10, then the switch will only have to provide 10w +losses no matter the poe standard. limiting the pi to a lower amount of power if it actually needs more could cause it to malfunction, in this case an upgraded switch would be inevitable. it should only use more than 15 watts with overly power hungry peripherals anyway, since the official usb c power supply only delivers that much. in short, you should be good

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@FloydS That is not correct for PoE. Most switches budget for what a device “could” draw and will deny or shut off power if the total requested power (not just the actual drawn power) exceeds the total power budget. This is because switches must approve PoE requests, and once approved a device can use up to what it requested at any time without further notice. Some switches allow overriding what the device requests, however these overrides are rather blunt hammers and do not always work correctly or as expected.

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Awesome, more power is just what I need for an upcoming project. Pre-ordered.

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Would it be okay to remove the fan if I install the pi into a case with a fan?

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as long as there is decent airflow everywhere it should be no problem where the fan is (i think its only for the cpu anyway, which under low load doesnt need additional cooling). but i would move the poe+ hat’s fan to the case, or connect the case fan to the hat, as to make use of the hat’s fan control.

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I was hoping you’d make one with a larger fan, current fan is just too small and noisy

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We have used CooliPi with PoE HAT#1 and the fan haven’t kicked in until we have loaded it to the max (the temperature went over 46˚C). We could have removed it altogether, without much impact on overall temperature :-D

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>In general, we’re weathering the shortage very well, and the supply of mainline Raspberry Pi computers, Zeros and our other products have not been affected (we’re very good at pipelining).
I’m excited to see this new PoE HAT, but if you’re not aware, it’s very hard for industrial customers to find Pi 4Bs right now. I build a product based on the Pi 4B, and I can’t find a single vendor willing to sell 2 GB or 4 GB Pis at quantities greater than one per order.

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Could you please drop me a line at liz[at]raspberrypi[dot com]? I can pass you over to our commercial team, who should be able to sort you out.

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Just emailed you. Thanks!

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Thanks Mike! I’ve passed it on to the right people, so hopefully you’ll hear from someone soon.

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I don’t know from where are you, but in Portugal you can still get them: https://mauser.pt/catalog/product_info.php?products_id=096-7401&src=raspberrypi

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They’re definitely available (although there’s a lot of demand at the moment, so some local suppliers may be experiencing some spikes in stockage). If you want to place a large order, please just email us – Michael did yesterday and we’ve already sorted him out with what he needed.

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Does the shield ground correspond to 0v or does it generate 5v as the difference from the 48v POE spec?. A third party version caused problems when plugging in a monitor to the Pi on POE+ (monitor ground = 0v, pi ground = 43v & pi 5volts = 48v compared to common ground)

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It should be isolated with a transformer, says spec on one of our official distributor’s webpage. But I’d inspect air gaps between mounting (including screws and hexagonal nuts) and the HAT’s electrical connections, and/or the Pi itself – if you insist on galvanic isolation up to 1500V RMS. Dry air has some 3000V/m isolation voltage.

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It’s worth remembering what the ethernet isolation requirements are and what they are not.

The 1500VAC (or alternatively 2000V DC) is a test voltage, NOT a working voltage. IIRC the test voltage matches the test voltage used by IEC standards for “basic insulation” but it does not come with any of the other requirements proper insulation standards do.

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Nice nice…but where pi 5? :>

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Maybe the increase maximum power for the new poe+ is for the PI5. Or is that just wishful thinking on my part.

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I doubt a Pi 5 is near. The insanity of the last year has to have disrupted development. I would expect a Pi 4B+ to come first but maybe not.

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as much as we all want one, id expect a new pi, either 4+ or (just very maybe) a pi 5 no earlier than next pi day (even if recent releases haven’t always stuck to that date)

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Interesting… This is a first, a pre-release announcement from the RPF. Probably won’t become a habit, though.

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It won’t, if only because none of us can stand Eben’s groaning.

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Seems not to be a pre-release. I ordered yesterday and I have a shipped notification already.

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Indeed, it has arrived this morning and it’s a quality little board. Easy evaluation task, no brainer. Two more ordered .

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This is great news! There are some projects where the ~15W limitation of af caused some issues (especially if you wanted to plug in any devices on the USB bus); having the extra juice available is a welcome change, as is slightly better thermals and a much sleeker transformer.

Of course you had to release the new one just days after I finished adding the original HAT to all my existing Pi 4s!

I have a PoE+ switch I’ve been testing with some cameras already—now it looks like the Pis will be able to take advantage of the extra juice too.

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Except that don’t we still have a 1.2A current limit shared over the 4 USB ports on the Pi4, so the new HAT may not be so helpful afterall.

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This is exactly what I’m wondering. Is the 1.2A limit a hardware limit, or can it be altered? I have some hungry USB devices that I’d like to use in a Pi. Does anyone know if this hat would let us give more than 1.2A to the USB ports?

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Is there any chance this can operate with passive PoE (24v) now or some point in the future?

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but … must the router (the delivered by your ISP) support PoE? :-/

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I would think you could just connect a POE switch to your current router and run from there.

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Thanks (y)

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The transformer and the ‘ideal’ bridge rectifier are very interesting devices. It’s great to see modern design out in the open like this. I’ve had a nice coffee break reading through the datasheet for the active rectifier. I’d love to read even more technical details about the design process, trade-offs, goals, etc.

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Is Gigabit Ethernet possible with the new hat?

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Comparing images of the current and new PoE HATs, the position of the fan seems slightly different. Will the PoE HAT case for RPi4 ( https://thepihut.com/products/poe-hat-case-for-raspberry-pi-4 ) work with the new HAT or will there need to be a redesign?

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What is a HAT?

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Replying to my own comment LOL…
…Forget it, I figured it out :)

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Hardware Attached on Top. :)

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At 25W (5V * 5A), will this latest+greatest support more than one board for power consumption? Not an EE by any stretch of the imagination; just wondered because another vendor claims that its 50 USD SKU can do just that (but I haven’t its docs on pin outlets to the secondary boards). Thanks.

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as a pi can both be powered and deliver power via the gpio power pins, you should be able to connnect them + ground pin(s) (and be carefull, full power on the wrong pin (5v on3.3v, or power without resistor on gpio, or short to ground may do damage afaik) to power one pi from another no matter the powersupply (as long as it delivers more than all the pi’s use)

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If I use this PoE+ HAT with my RPi4 and a good PoE Injector can I connect 4 external USB hard drives ?

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i’d say that depends on your drives, but you would likely at least need to spin them up (peak power draw) one after another, either with a program/script or by manually plugging. but remember two of the usbs are only 2.0, and two drives on one 3.0 port might be to much. ssds use much less power and will probably work fine, even two on one port via unpowered hub likely isn’t a problem

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I was planning to use 4 external hard drives with 4 USB ports on OpenMediaVault. So each drive with its USB port. If this would work then this HAT worth buying.

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if Pi can be powered by POE HAT, can USB C port be re-used for something else?

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i think it supports usb 2.0 or 1.1 for communicating with powersupplies, which in theory should make it usable, but afaik its not an official ability so you will have to try it out (maybe deliver 5v via gpio if you want to save the 20 bucks for the hat)

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Hi.
I wonder if anyone could clarify the exact flavour of POE implemented in the new HAT, as some of us have access to both ‘af’ and ‘at’ PSE switches, with varying levels of ‘compliance’ to the af/at specs.

I could do with knowing what POE mode the HAT (PD) expects to find the PSE sending the power on? Mode A (Pins 1/2, 3/6) or Mode B (Pins 4/5, 7/8).

Also, is the HAT just a ‘passive’ receiver of ‘always on’ power from a midspan or endspan injector, or does it actually do the power range negotiation procedures with a properly-compliant PSE/POE switch? If the latter, I take it’s the simpler current/voltage negotiation, not the awkward LLDP option?

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I’m struggling with the same problem. Did you figure it out?

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I cant find any info if it is possible to still use the GPIOs with the HAT attached. Can anyone confirm this?

Alex Bate

Sure is. The POE+ HAT is designed to accept a GPIO extender.

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Looks like it’s goning to be a excellent product at a good price. My POE+ Hat arrived this morning (Thank you Pi Hut ). On my HAT (2116-A with (c) 2021), the fan is fitted with M2x12mm screws. They need to be M2x10mm so a screw doesn’t hit the camera connector.
You can see the problem here (https://tiny.one/poe-10). I fitted a 10mm long screw & it solves the problem.
Now to power it up!

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I hadn’t noticed, but mine is the same. Just the one screw needs changing, but both to be tidier. When the supplied metal spacers are used, the board is bent slightly with pressure on the camera connector. Bit of an over sight.

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Afterthought. The old PoE hat has the same 12mm m2 bolts but in a different position. Makes me wonder if this was designed for a different (future) board.

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It’s possible that the fan may have been changed, and it’s now thinner than the one originally used. Compare your pcb with the stock one at Pimoroni or The Pi Hut and you may notice that the lettering below the fan is different (mine is), and my board says (c)…2021.
I think I’d also like a small dab of threadlock under the nuts as it could be catastrophic (to the Pi) if they fell off.

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There’s not a discernable difference in the thickness of the fan housing. The PoE hat bolts also protrude beyond the nut. The reason the PoE+ bolts foul the connector is because the position of the fan is displaced a few mm diagonally.

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I would need some clarification please. Here on the website, maximum output current is 5A. But on the PDF file provided, it says 4A. So which one is it ?

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Tried two units both with fresh installs of raspbian and updated Fans do not work. Old PoE works no issues. Think there is a problem with the 802.3af implementation.

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I did an update and full-upgrade (on Wednesday 26th) and the fan didn’t work. Thank you for telling me it’s not just my board… I see a new OS was released today. Perhaps that’s the answer?
PeterF

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Well, yes! It was the answer. Looks like the new OS version was released late afternoon. I’ve just done another update and full-upgrade and the fan is now working! Hurray. I guess Pi Towers (PT) was caught on the back foot since they thought that product wouldn’t be in the wild until June. But PiHut and Pimoroni have been showing stock all week.
Still got to sort out the BOM and substitute shorter screws for the fan though… PT have been very quiet on that front.
Anyway, it’s good that we’re getting there.
PeterF

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Is it possible to get the sensor data / fan status from the HAT?
My Pi4 got 89°C CPU Temp an the Fan is not running…

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The fan starts by default at 75C (from memory); you can configure it, though.

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How can I configure it?

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Found out that the product was just too new for my OS.
apt upgrade made the fan work!

The drivers were merged just a few days ago.
https://github.com/raspberrypi/linux/commit/b422a76345d5329ad232ca6701b5f21ac9f8c62b

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Please make a new version of the Raspberry Pi Zero W (1GHz, eMMC 16Gb maybe)

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1-1.2 GHz CPU, 1-2 GB RAM, 16-32 GB eMMC

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Fun idea, but probably not imminent. (Suprise me, Pi Towers!)
I’ve been hoping for a while that BCM would make them a custom chip with a single A53 and VC4 with POP pads, that could serve as a drop-in replacement on the 0, B, B+, CM, anything else they still make with the 2835…

This is what they did with the Pi 2, which has been 64-bit since shortly after the BCM2837 launched. However, going from ARMv7 to ARMv8 is a much smaller jump than going from ARMv6 to ARMv8, and my entirely uneducated brain has a running theory that this would break the older Pi’s for industrial uses, so can’t be done.
And the 0 is too low-margin to justify it’s own unique CPU.

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Does the new hat work with Ubuntu? The fans remain inactive after boot…

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Hello, I have noticed the problem with the poe-hat V2 and ubuntu / pi4. I had no problem with version V1. Otherwise it works well V2 with raspbian after the firmware update. Do you have more information on the problem with ubuntu? Thank you

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I’m surprised to find that the official case doesn’t seem to fit the PoE+ HAT!? I’ve just bought both can can’t put the top lid on :-/
It seems the PoE HAT had a notch for the stand in the top section of the case while the PoE+ HAT doesn’t. Should I “just” snap it off?

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I’m surprised by the heat issues I’m seeing. Pi previously ran around 42C on lowest fan setting (lev1, always on). Now it keeps going up to 65C and escalating to lev3 fan (and would probably keep going over 70C if I forced it to stay on lev2).

This does not look *at all* like the “it runs cooler” we’ve been promissed.

(4+ B Pi, 8GB, no USB peripherals, just Ethernet PoE+)

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Can you add an issue in github against the firmware and we can diagnose.
https://github.com/raspberrypi/firmware/issues

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Hi there RPi Foundation,
Great news on the uprated PoE+ HAT…thank you very much.
I’ve just bought 5 of them to replace the older v2 where the fans are noisy and for the extra power.
I have some issues that I would like to share with you if I may. There could be some user error here but hopefully if there is you can point that out! :)
1. The fan position on the new PoE+ HAT has changed so now the ventilation slots in the new Uputronics GPS HAT for example obscure the fan. May be an issue with other HATS?
2. The extended tall 4-pin header now cannot be used to connect/stack as the 4-pin header on the PoE+ HAT has no pass-through unlike the older v2 HAT and when using the extended/tall 40-pin header it lifts the PoE+ HAT above the 4-pin header on the Pi? I suppose another 4-pin header of the right size might resolve that but it is annoying.
3. There is no camera ribbon cable pass-thru’ slot on the PoE+ HAT unlike the earlier version?
4. When you fit the supplied screws for the spacers the Pi4 no longer fits into the official RPi case as they impact the locating posts! Possibly the same on other cases?
5. Also with the official RPi case you can no longer clip the top lid on as there is now no gap at the back of the PoE+ HAT for the plastic lugs to locate unlike the notch on the earlier boards!
Apart from that all good! 😊
Thanks for listening!

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What is required in order to install another HAT on top of the POE+ HAT? Is it possible to do that?

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I have purchased the new PoE+ HAT and comparing it to the previous version of the PoE HAT I’m very disappointing…well at least with the fan. It is very noisy and after few minutes of working in the same room, I’m unable to keep my Pi attached to it connected. I have read about the new bearings but they are not exceptable and I have to consider another fan option.

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What is really anoying me are the following points:
1) Camera cable pressed (no slit)
2) Long fan screws hitting the camera cable, have to exchanged to 10mm ones
3) If you need the GPIO ports you have to use extenders (+height) and at the end the beast is not anymore compact and fit in normal cases
4) Fan noise extreme loud, you want the Pi to use PoE, so you are in a normal living area and not in a noisy data center room

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Today my fan stopped working after a month all of sudden I’ve noticed high temp on my raspberry pi 4. After a while I’ve figured out that fan stopped spinning and it started only after small push of my finger. Do you have any idea what’s the issue ?

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I’m running the latest kali image for RPi and not able to get the fan working, I found some information about loading the raspi-config and rpi-update packages, but still nothing, any help would be greatly appreciated

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How do you access the 40pin GPIO?

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