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. Production lifetime: The Raspberry Pi PoE+ HAT will remain in production until at least January 2027 Dominic 10:01: And that has the fan. Yes. And so there’s been a lot of 3D work to make sure it all fits, and it’s all very compact, but you can now have a case with a built-in fan and a PoE solution, all nicely together. This is, once again, a machine transcription that has been edited by a human; if you spot anything that’s obviously off, drop us a note in the comments.

Thanks to improved thermal design it should run cooler (measured at the hottest point on an uncased board) at any load. The Pimoroni IO Expander is not a typical add on board for the Raspberry Pi. Measuring a mere 1 x 0.9 inch (25 x 23mm) the board has only five connections which are made to the GPIO. The need for so few connections is due to the IO Expander using I2C, a two wire serial communication protocol. These five pins can be soldered to using the included male / female header pins, then placed atop the I2C pins of the GPIO. This design is not accidental, rather it is deliberate as the IO Expander is part of Pimoroni’s Breakout Garden range of boards. And this doesn't matter to me so much, but the new HAT doesn't fit in the official Pi 4 Case. It's just a bit too big. I never use the HAT in any enclosed case so for me it's not an issue. But it is a little annoying that the old HAT did fit, while the new one doesn't.So I bought a replacement Raspberry Pi 4. I was able to boot it with the same SD card, with no changes to it's contents. Ubuntu came up just fine. It seemed to work exactly as the previous one had. Dominic 2:53: Yes. But there are also the two power ranges, the 13W and the 25W power range, right, so then the Pi can detect which power range is available. Dominic 9:23: Yes. And so it had this big hole in the middle of the PCB, so there was a lot of wastage of the PCB, because it just gets thrown away — Devices like SSDs consume around 3W, and two of them together would be 6W. According to the Pi documentation the Pi 4 itself, minus the USB usage, should have 9W available to it for stable operation. Dominic 2:32: Indeed so. Yes. And there’s one other thing it does, is all the PoE negotiation as well. So it will negotiate with the switch.

The problem they reported was this: when powering certain Raspberry Pi units via the PoE HAT, it was not possible to draw the full rated current from the USB ports. I don't know what the limits are on the USB current, but would guess 5.08V x 0.46A = 2.3368W is too much against 4.97V x 0.37A = 1.8389W. Perhaps 2W is where the limit is ? An up to date copy of Raspberry Pi OS (and the latest kernel) is required for this HAT to function correctly. We recommend a fresh install of Raspberry Pi OS. Dominic 3:18: Through the switch. Yes. And then it applies a voltage to the cable, to then try and detect a resistor of a particular value. And if it can detect that, then it knows which power range available. There are more advanced methods for the higher, for PoE++ that we were referring to, but we don’t do that, so no need to describe how all that magic works.The Raspberry Pi Power over Ethernet HAT is a small accessory for the Raspberry Pi computer. It can only be used with the Raspberry Pi 4 Model B (launched June 2019) and the Raspberry Pi 3 Model B+ (launched March 2018). The PoE HAT allows you to power your Raspberry Pi using Power over Ethernet–enabled networks; for this product to be used, the network it is connected to needs to have power-sourcing equipment installed. Supplied with this product