I think I may have found a solution for controlling the LEGO+ module.

It turns out that when you install the arduino library for the M5Stack, there is an example to interface the LEGO module. It is located in File>Examples>M5Stack>Modules>LEGO_PLUS>LEGO_test

From that example code the I2C commands can be figured out. I hope this information is useful to anybody facing the same issue as me

I am planning to control a 2-wheel robot by using the M5-stack Gray version and the LEGO+ module.

I want to program everything by using the arduino IDE (not the UIflow). From what I understand looking at the schematics of the LEGO+ https://docs.m5stack.com/assets/img/product_pics/module/lego_plus_sch.png

The ATMEGA328 is connected to the encoder signals of the motors and to the L293DD, so the code to read the encoders and to drive the motors is preloaded in the firmware of the ATMEGA (I guess that the ATMEGA works as a I2C slave).

The problem is that there is no information about the I2C commands that the M5Stack (the ESP32) have to send to the ATMEGA to read the encoders' values and to drive the motors

Thanks in advance for any help that can be provided

Is there any code available for the LEGO+ board and the arduino ide?
I have looked in the github and tried to google online but there are only examples for Uiflow and the "firmware" for the 328p is not very useful.
Please help!!