Raspberry Pi PoE (Power Over Ethernet) Hat

So I plan to use the PEO hat for a hobby project but I need to connect a pi camera (should be no issue) and I need to have access to the

GPIO pins. What is the recommended solution to get that done? Will the 40 pin stackable header work painlessly (e.g. not make the pin plastic bottom stand out too high and make connection to the PEO header painful)?

I spoke with someone at Newark Canada about a month ago-they wouldn't even estimate on the wait time....

So... ETA?

Somewhere, I'd seen that it was targeted to start shipping from Newark / Farnell about a week ago.  Waiting with baited breath...

Power over Ethernet uses the fact that the signals are defined to have transformer isolation one each pair. With POE, the voltage is applied between the center taps of the pairs.

You need the transformer coupling because the devices on the two ends likely have differing ground references, so you need the transformers for isolation anyway. By applying the DC bias to the center taps, POE is largely transparent to the data transmission.

dhussenet  wrote:

 

Hi Everybody. I'm sorry but it will not use the 40pin GPIO connector.

 

Power is taken directly on the RJ45 connector, and on the Pi3 B+, there's a new 4pin connector (close to the USB connectors) called PoE. So, 2 pins for the input voltage from the RJ45 connector (35-56V tolerant I think, so conform with 48V of the 802.3af), and 2 pins for the output voltage (5V@2.5A max)

 

The HAT will be connected to this connector to do the job, leaving the 40pin connector completely free

As much as I'd like this to be true, this is incorrect. Each of the 4 new pins is connected to one twisted pair of the RJ-45. So you still need to use some of the pins of the 40-pin header or the input USB to provide power to the PI. I've verified this with a multimeter.

woops we did measure again

the 4 pins connect to regular rj45 input, good tomake our own poe input

I'm a little sad that this doesn't appear to support Ad-Hoc POE (unless I'm mistaken).

I use this midspan injector to run stuff at my house.

Unless I'm mistaken - could the 4-pin header be used to just run a regular voltage regulator to step down, say 12VDC to a decent 5VDC back to the board?

The other reason for this is that the Pi has lots of power conditioning on-board and doesn't have any "VIN" pin available on the header. I've done projects where I'd like to bring power in via a Hat or perma-proto board (like in ad-hoc POE) but then I lose out on all the power regulation.

I'll have to do some more research to find out...

i did not do it myself, needs a double check

shall let you know

Hi Thomas,

how did you measure?

I checked with my Raspberry Pi 3B+ and there all 4 pins are connected to the pins of the RJ45 connector.

Bernhard