Below is from the User Guide:
[J38] The Power over Ethernet (POE) header exposes any DC voltage present on J43 Ethernet jack per IEEE 802.3af.
Normal PoE supplies 48VDC, and the Nano takes 5VDC. Therefore we can’t power the Nano with PoE directly.
So what is the application of the [J38]?
Same question as You. Is someone from nvidia may clarify this topic.
p.s / memcpy : At the beginning, I thought the j38 was to provide current to j43 with PoE capability for devices such as Gige-v camera…
That header passes through the high-voltage 48V PoE supply from the Ethernet port so that it can be stepped-down or regulated by 5V PoE hat or voltage regulator. This regulated 5V supply can then be passed to the 5V input pins on the 40-pin header.
An example PoE hat that can do this automatically is here: https://www.raspberrypi.org/products/poe-hat/
It will take the 48V high-voltage from the header, step it down to 5V, and pass it back to the 40-pin header. It can be mounted on top of the Nano devkit. Or you can do this manually by wiring in your own 48V->5V regulator.
So J43 ethernet jack can’t supply power to a Gige camera while the Nano is already powered through another source?
I can’t seem to find a pinout of j38 - there is nothing in the manual. Can anyone help?
Also, the manual says that POE should be IEEE 802.3af. What would happen if i plug in IEEE 802.3at (POE+)?