[ESP32-POE] Enable/disable PoE + questions

Started by gpiazza94, January 17, 2019, 04:00:47 PM

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I just bought the ESP32-POE board and I have some questions about it. I am mostly using the Arduino IDE, but if you guys have the solution for these questions on the ESP-IDF I have no problem using it :D

If you know the answer to only one of these questions, it would be of much help already.

1. How to enable/disable PoE.
   - From what I've seen, this line should enable it. Is it right?
        #define ETH_PHY_POWER 12

2. My USB-ISO didn't arrive yet, is there any way I can program and, after programming, connect the Ethernet as power source without or with little risk of damage?
   - I have tried to use the example https://github.com/OLIMEX/ESP32-POE/tree/master/SOFTWARE/ARDUINO/ESP32_PoE_Ethernet_Arduino. I programmed using the USB port with the ethernet cable disconnected and then I pluggled the ethernet cable (both USB and ethernet connected). It seemed to work well, the serial monitor output was ok, but when I unpluggled the USB the board was shutdown. I thought that, once the configured power source is PoE it should stay ON, even if only the ethernet is connected. What is wrong with this experiment?

3. I have a project that I'm planning on using the ethernet as my only power source. The project does not require much power. Is this board ready to support the ethernet as the only power source or do I need to buy any extra hardware?

4. If I disable PoE, can I use the ethernet + USB safely?



1) Yes, changing the state of ETH_PHY_POWER pin would power the Ethernet down or up.

2) You shouldn't have USB power and PoE power connected at the same time - this might burn your PC in a matter of miliseconds. What do you use as PoE injector - does it comply with IEEE 802.3 standard? Can it provide sufficient voltage?

3) Yes, sure. You can draw probably up to 800mA at 5V.

4) Yes.
Technical support and documentation manager at Olimex


Thank you for the answers @LubOlimex.

1. So in theory if it is set to zero or a negative value it should disable, right?!

2. Probably my injector, or my router, is not working properly. I'll dig further to understand the reason and buy another if that's the case.

3. Perfect!

Thank you again for the support :D