I want to enable PoE oh my rock 5b but without the use of a hat.
I’m looking at this page: https://wiki.radxa.com/Rock5/hardware/5b and it shows pins 2 and 4 for PoE.
I don’t quite understand the importance of that in relation to PoE. What do i nees to do with those pins?
You can’t enable PoE without a PoE hat of some form. All the Rock5 does is break out the 48v power that is delivered over the Ethernet cable onto the 4 pins near the Ethernet jack. Something (the PoE hat) needs to convert that to 5v to power the Rock5 - which the Hat delivers on pins 2&4 of the grid header.
Hmm so the hat not only connects those 4 pins to the GPIO pins 2 and 4 but also does some conversion?
Yes, you need to convert the r8/52V POE voltage to something the Rock5b can use.
Ah ok. Can you point me to a starting point where I can figure out what the 4pin Poe provides and what the rock5b expects?
I currently have my rock5bs in the radxa metal case so I don’t think a PoE hat would fit inside the metal case… Maybe a barebones PoE could be made?
You can buy a POE splitter that will output to usbc. I have 2 for a RaspberryPi
Ah that sounds like a good alternative… so it takes a PoE connection and splits it out to regular ethernet and a usb c connector right?
The problem is looking for one that support 2.5GB input and output and poe+ lol.
You won’t find one. You could use 2 ethernet cables (1 for the POE split and 1 for data) or create a cable from the poe pins to the poe power board.
2.5Gbe POE is too new and most deployments would just use 2.5Gbe injectors for any Acces Point that might require it. The Rock5b is the only device I know of that would need such a thing.
Ah damn… Maybe I would need to use a PoE hat after all.
Is there even such a hat for this yet? I see one for rock pi 4 but I don’t think it’s compatible with 5.
The PoE hat is compatible, but there is no fan control as of yet - perhaps @amazingfate will come up with a solution like they did or the Rock3a 
How is this compatible? The form factor of that PoE hat looks like it will not fit the Rock 5B at all.
I have indeed a rockpi5b and a poe hat ROCK Pi 23W PoE HAT found in :https://wiki.radxa.com/ROCKPI_23W_PoE_HAT. However it doesn’t mechanically fit onto the rockpi 5b board .
so could you please explain how did you manage to use it with a rockpi 5b ?
Actually it does fit on, but you need a different fan which I’ve also tested and got working, but the main concern was the fan position as it doesn’t sit directly above the CPU.
Since then I contacted Radxa and they have informed me that they are indeed making a PoE hat specifically for the rock 5 which will be available in April.
I purchased a different fan and soldered on a Micro JST 1.25mm 2-Pin Connector which is the mechanical presentation on the board, but it’s pointless due to the position of the fan
thanks for your updates ! I will certainly be looking forward for the new poe Hat release !
Regards
Any updates on this front?
I’m currently using a USB PD brick to power my two RockPi 5Bs but want to power them via PoE. They’re already connected to a 2.5G PoE+ switch.
August already. Any news about the PoE hat?
The Waveshare HAT works great for me on my 2.5 Gb switch.
Looks like the poe hat is out:
Though my next question is, will I need to download and install drivers for this?