ESP32-POE and ESP32-POE-ISO do not power on over PoE

[xxcn]

I am using a "china's finest" switch which claims IEEE 802.3at/af compatibility:

https://www.ic-intracom.bg/bg/8538/gigabitov-poe-suich-8x10-100-1000m-rj45-2xgigabit-uplink

Both ESP32-POE and ESP32-POE-ISO boot and work fine when powered over USB. The ISO board's ethernet interface works when ETH is connected and USB is used for powering.

Both boards do not light up from the PoE switch. I tried multiple cables and ports. When looking at the voltage across pins supposed to deliver power, they seem to cycle between 50V / 3.3 V / 0 V with .25 or .5 seconds in each state. I'm guessing the PoE handshake doesn't go through for some reason.

Other than returning the switch and trying a different one (let's hope the vendor will take it back), what are my options for debugging this?

[LubOlimex]

Does this switch have web-interface for its settings? Maybe something can be changed in the settings?

Maybe test with another cable and double check if the cable fits well into the ESP32 board.

Try all PoE ports of the switch.

Testing with another PoE switch would definitely speed up the debugging. If you can - do that.

What are the hardware revisions of ESP32-POE and ESP32-POE-ISO boards?

How do you determine boards don't work when powered from that switch?

[xxcn]

> Does this switch have web-interface for its settings? Maybe something can be changed in the settings?

The switch is dumb, non-manageable and has no settings, switches or other control interfaces whatsoever.

> Maybe test with another cable and double check if the cable fits well into the ESP32 board.

Tested with at least 5 known-good pre-patched cat6a cables. Also tested other PoE-powered gear on the switch, and it works fine. A PoE router and a PoE power splitter both lit up and worked fine, powered from the same switch.

> Try all PoE ports of the switch.

Check.

> Testing with another PoE switch would definitely speed up the debugging. If you can - do that.

Tried with an Ubiquity power injector (comes with one of their high-end APs) and the board did light up and boot fine.

> What are the hardware revisions of ESP32-POE and ESP32-POE-ISO boards?

Both are Rev L, came with order W-KZ261123.

> How do you determine boards don't work when powered from that switch?

First and most obvious sign is LEDs don't light up. There is no voltage across GND and +3V3 or GND and +5V.



So, in short:
 * the boards work with an Ubuquity power injector
 * the switch is able to power other PoE gear
 * the combination between ESP32-POE[-ISO] and the switch doesn't work


At this point, I can give up trying to debug, attempt to return this switch and gamble by buying the the 10/100M version or something more expensive/reputable, but the mystery will remain unsolved.

I can ship the whole assembly to you so you can check for yourself. This is for a long-term project and I don't need the gear urgently.

Or, I can follow instructions for debugging, to try and figure out where the incompatibility comes from.

[LubOlimex]

Based on your replies I'd say probably the router is either generally bad or faulty.

ESP32-POE and ESP32-POE-ISO are popular boards, they'd been selling for few years and we haven't received similar complaint, you can also see that here in the forum there are no reported compatibility issues with certain routers. My advice is to get that router either replaced or steer away from that brand altogether.

[xxcn]

An update: the vendor took back the gigabit PoE switch and let me test the 10/100 version from the same vendor on-site. Both boards worked with the 10/100 version.

[LubOlimex]

Thanks for update, will keep an eye out for similar reports with GbE switches.