esp32 poe - not link on link speed 100Mbps

[PetrSmolik]

I have 5 pieces of esp32 poe board. All of them were connecting 100Mbps. Now something happened on one of them and whatever I upload, it only connects at 10Mbps. he others once at 100Mbps with the same program. How to switch back to negotiate the connection to 100Mbps again?

[LubOlimex]

What software are you using? Try different software, might be some bug in the software or related libraries.

[PetrSmolik]

I upload the program using Arduino ID 1.8.19. The ETH library is directly from Olimex. But completely empty program, just ETH.begin, loaded into two boards. One connects at 100Mbps and the other at 10Mbps. Probably there is some setting directly in the EEPROM of the board. It changed by accident. A week ago, all the boards were connecting at 100Mbps.

[LubOlimex]

The boards are supported in the official Arduino package for ESP32. So, if you haven't already first install the official package, follow the advice here:

https://docs.espressif.com/projects/arduino-esp32/en/latest/installing.html

Then go to Tools -> Board -> Olimex ESP32-POE and select it then also select the COM port of the device.

Then load the default example for Ethernet, from File -> Examples -> Ethernet -> ETH_LAN8720. Compile and upload.

Compare behavior.