Introducing the PoE HAT – available now!

In March 2018 we announced the launch of Raspberry Pi 3 Model B+. One of the many features added to the new board was the ability to be powered through Power over Ethernet (PoE) with a HAT. We are really pleased to announce that the PoE HAT is on sale from today.

Raspberry Pi PoE HAT Power over ethernet

The HAT connects to the Raspberry Pi 3B+ 0.1” headers: the 40-way GPIO; and the new 4-pin header near the USB connectors, which allows you to power the system using your Ethernet cable.

Power over Ethernet

Power over Ethernet is a widely adopted standard that places power on the Ethernet cable along with the data. It has no effect on the data, so you won’t lose bandwidth by using PoE. There are various standards of PoE; this HAT uses the most common standard 802.3af, which allows delivery of up to 15W. This means that the HAT is capable of providing all the power needed for running your Raspberry Pi. You will need power sourcing equipment to power your Pi. This is either provided by your network switch or with power injectors on an Ethernet cable.

Raspberry Pi PoE HAT Power over ethernet

Using the PoE HAT

The HAT is a compact, single-sided board that sits within the footprint of the Raspberry Pi. It will fit comfortably inside an official Raspberry Pi case. A small (25mm) fan is pre-installed on the board. We see the product as a useful component for people building systems that may be in tougher environments, so the addition of the fan helps with cooling. The fan is controlled over I2C via a small ATMEL processor which allows for it to be temperature-controlled: when your Raspberry Pi processor hits certain temperatures, the fan will be turned on to cool it down. To enable this you will need to get the latest firmware (sudo rpi-update).

Raspberry Pi PoE HAT Power over ethernet

Because the fan is controlled over I2C, none of the GPIO are used, so you can stack a second HAT on top of the connector. To do this you will need to buy some longer pass-through headers that expose the pins on the other side of the PoE HAT. You will need one for the 40-way and one for the 4-way connector that has the PoE splitters on it.

We’ve tested a variety of pass-through headers and can recommend the 2×20 pin header from Pimoroni and the 4-way risers from RS and element14.

Getting mains power to remote areas of buildings is often tricky. PoE support enables this with just an Ethernet cable, allowing you to provide power (and data) to your Pi wherever it is located. With the improved network booting you can now dispense with not only the power supply but also the SD Card, making deployment even cheaper for a Raspberry Pi based system in your factory or workplace.

Get ahead, get a HAT

We are very excited to see what new projects this enables for you. The Raspberry Pi Power over Ethernet HAT is available for sale now at $20, from Farnell, RS and The Approved Reseller Network.


Edit: I just saw this online and thought it was cool – Alex


William Smith avatar

If those “4-way risers” are the same as what’s soldered to the HAT board, I’m not sure they’ll work. According to the drawings at: they have 3mm leads, but the contact point is 5.1mm into the socket.

Looks like you need something with an 11mm post to match the Pimoroni standoff headers….

Eben Upton avatar

The 4-way riser is not the same as what’s soldered to the HAT board.

mahjongg avatar

This “HAT” does not really confirm to the normal definition of a HAT, as normal HAT’s are NOT stackable.
In this case some clever tricks were used to make the stacking possible.
As I understood, the PoE HAT does have the EEPROM that any normal HAT has, but it uses a different address! Its also not a regular EEPROM, but a microcontroller programmed to act like one, but with extended possibilities, so it can also be used to control the PoE and ventilator functions.
A modification was done to the normal Raspbian EEPROM reading code was done to support the PoE HAT.

Liz Upton avatar

Meh. Given it’s an official product, I think we can probably have a reasonable claim to being able to decide whether it’s a HAT or not! (Hope you’ve recovered from the camping!)

crumble avatar

Normal HATs seems to be stackable in real life. But you may have to jumper the address. Which is the convenient part of the work, because you have to find a way how to stack them physically. Adafruit seems to be the the only reliable source to get the pin headers. Living outside the US, this is not cheap. You can order more stuff to reduce shiping cost per part, but than you have to pay more tax :-|

Anyway, it’s not smart to stack HATs on top of the fan and place that in a neat fitting case. Out of the box solutions will seldom work with such a configuration.

User avatar

what about cases?

Liz Upton avatar

As Roger mentions in the post, it fits very happily into the official case. We haven’t tested all the cases out there because there are thousands of them, so if you do try one and find it does/doesn’t fit, it’d be really helpful if you could report that here or in the forums!

Lars Hult avatar

Some standard cases have small pins at the button to secure the raspberry and the “Poe hat” is attached with screws that cant be there because of the pins.

Martin Rowan avatar

I simply removed the location pins with the aid of a sharp knife.

Cohen Eyers avatar

The official case has that too, and as Liz said, it was tested with one, and it worked great. I don’t think you’ll have to worry too much about pins.

Nick avatar

Akasa has aluminium cases for Raspberry Pi that are compatible with the PoE hat. More specifically these two models:
A-RA03-A1B (, and A-RA02-A1B (

John avatar

Please correct me if I am wrong but with all the 3B+’s that I’ve been playing with the Ethernet interface doesn’t seem to come up when using certain kinds of PoE power supplies. At least on 1000BASE-T networks I’ve had to use power supplies that specifically use phantom power over all four pairs. For example, a product like this works:

But if it doesn’t say Gigabit or 1000BASE-T then it may not.

2ez4z avatar

So I had some what the same issue, using my FortiNet PoE switch. I resolved the problem by statically setting my switch interface to 100Mbps vs Auto detect. Then my RPi3+ came right up with the PoE hat.

John avatar

Thank you! I’ll try that.

Dennis avatar

The standards for POE on Gigabit Ethernet are quite different from 100Megabit Ethernet. Beware.

Rob Bakaladurkdurk avatar

There are actually 2 POE standards. Back with 10/100 only 4 wires were used out of the 8, so one of the standards sent power on the unused wires. With 1000, there are no unused wires, so the power hast to be multiplexed with the data.

Mark avatar

On sale from today? I’m sure RS has had them on sales for weeks, now, if not months! Are we talking about the same thing or have you done something to it to make it a PoE 2-point-oh?

Chris avatar

Is the original PoE supply exposed through one of those 4 extra pins? I wanted to know if the PoE Hat can be used to ‘pass-through’ the original source power (48V) to secondary devices that are located a variable distance away from the 3B+. The use I had in mind was for a couple of PiZero Zeros with Raspi module cameras. I had assumed to drop voltage at the PiZeroW, but hoped there might be a simpler way.

William Smith avatar

FWIW there’s a piece of Kapton tape covering the extra socket on the three I got today thru (in case the channel matters). Not insurmountable but might cause confusion, and you probably want to fix your production process…

Peter Bindels avatar

Can confirm I also had a piece of kapton tape on the 4-pin connector, ordered through

Mike avatar

I too had the tape on the four pin connector. Order supplied by Newark

Trevor Harris avatar

To me one big advantage of the pi is no moving parts and no noise so the fan is a disappointment. Is it possible to make a version without a fan.

Tomi avatar

Can’t you just remove the fan? Disconnect it and remove the screws.

Chino Pisces avatar

Besides, the fan is nearly silent.

Charles Johnson avatar

If you look in the forums, there are instructions on how to change the temperature threshold for when it begins to spin up, along with instructions for how to adjust the speed – including to zero.

As I’m in the no-noise-loving camp, if/when I get some Pi 3B+s w/ PoE HATs, I’m currently thinking that I’ll set the threshold for the fan to be around 70 C. That should give me silent operation, but also, should the CPU temp hit 70+ C, give it cooling well before it hits the 85 C mandatory throttling point, at which point, noise will not be a concern…(!) Also, I’ll probably secure the HAT to the Pi with stand-offs that are taller than the ultra-low profile ones shown, thus increasing airflow and lowering the amount of ‘self-heating’ heat (from reduced airflow, etc).

My $0.02,

Charles Johnson

Jack Wol avatar

What’s about WoL (wake on lan)?

Chris avatar

My PoE Hat is chirping (silently) while powered on and really noisy when the system is powered off. Can someone confirm this behaviour, or is my HAT faulty?

WPM avatar

I claim to be an educated, charted electronical engineer with at least 3 decades of experience. Relying to the official specs I ran into trouble and found this:

Any qualified official comments about that infamous issue HERE? What about quality assurance?

Scott avatar

Allied Electronics is telling its customers who want to buy the POE Hat that it is quarantined by the Pi Foundation and should not be used. I just bought 3 of these earlier in week and they blocked ordering a 4th one. Not sure if I should use the 3 when I receive them.

Pi Foundation from what I can tell has not made any announcement.

See customer representative response below:

This is the info that I have received so far from the Pi Foundation. As I receive more info I will pass it to you.

Thank you,


We will get an official communication from the Pi foundation on this topic tomorrow hopefully (they are working on it).

There is also going to be an official statement on the Pi foundation web site.

I will keep you posted as soon as I know more.

Overall, I do expect the board to be taken out of the market though…. (just my expectation)

WMA avatar

Thanks – shipped back to distributor for refund and proceed with reliable chinese 1G/s PoE solution for half the price.

Sven Haiges avatar

If someone else feels the POE fan needs more user-controllable settings, please consider voting / starring for an issue I created =: … 3Aopen+poe

TLDR: make the fan user controllable with different operating levels in raspi-config.

BTW my hats are also chirping and I was unplugging and thereby ruining one already. Damn…


pssc avatar

So this is a class 2 poe device so 7 Watts max not 15?
POE Power Class 1 2 3
PSE Power available 4.0W 7.0W 15.4W
Max device power 3.84W 6.49W 12.95W

Eric avatar

Will the POE hat be coming back? I have a remote application that can work if I have POE. I will happily wait for it, but please tell us you plan to bring it back…

Liz Upton avatar

It will – real soon now. Watch this space!

Ebrahim avatar

it might be good to have additional adds-on on this HAT since it has a lot of unused space e.g. microphone as far it is not adding extra cost.

Lee Harris avatar

I am putting together a project stacking a Raspberry Pi 3 B+, a Raspberry Poe adaptor, and a Justboom Amp Hat on top. I am having trouble connecting the 4 pin header, the recommended extender above is too short. I need assistance getting the right headers. The link above to the 4 pin header takes me to the header at this link here

I mounted the 4 pin header but it is too short. The 40 pin extender fits perfectly but not the 4 pin one. The 40 pin stacking header I used was this one here×20-extra-tall-header.html.

I note someone posted above “If those “4-way risers” are the same as what’s soldered to the HAT board, I’m not sure they’ll work. According to the drawings at: they have 3mm leads, but the contact point is 5.1mm into the socket.

Looks like you need something with an 11mm post to match the Pimoroni standoff headers….”

I cant seem to find the right header to finish the setup can you please help.

Daniel avatar

I’m in the same boat. I bought the 11mm 40pin extender, which works great – the GPIO pins are exposed so I can connect the touch screen to power. However, I haven’t found the right 4 way 2 way extender for the PoE. I’d rather not ship from UK to US just to find out its not the right pins :/

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