@m5stack Hello!

I would like to know to which bronchi pins A and B of the RS485 extension card are connected to the BUS, please.

I can't get my M5 to communicate via RS485, however I soldered the small expansion card well.
For my program I am using an ESP32 based Arduino library for the Modbus RTU

J'aimerais faire communiquer mon M5Stack core + module LAN PoE avec un Automate Unitronics via le protocole Modbus RTU RS485 (half-duplex: R - => B & R+ => A). Je suis donc à la recherche d'une aide pour le développement du programme sur Arduino. Je n'ai pas trouvé de bibliothèque ou un exemple de programme, je suis donc un peu embêté.
merci pour votre aide.

@lukasmaximus comment faire pour implémenter ce convertisseur de niveau logique?

Hello Felix, Thank you for your feedback.

I am new to the subject, but I still tried to modify the Wifi library but nothing to do. I do not see how to do with the Ethenet.
really if someone has a solution I am interested in doing tests

 I'd like to know if anyone's ever programmed the M5Stack core basic + PoE LAN module as a modbus tcp ethernet slave on arduino.
If so, which library did you use? Could I get a sample code?
I'm new to arduino programming and I'm just discovering the M5Stack.
thanks for your feedback