Configuring serial communication with Raspi

Hi everyone,

I'm desperately trying to control my Nybble using the ardSerial.py executable, in order to try other python scripts and try to add computer vision.

I've configurated my Raspberry Pi 3b+ as explained in the assembly instructions : https://docs.petoi.com/chapter4#4-4-raspberry-pi-serial-port-as-interface

The 2 boards are communicating but the sketch doesn't start because the MPU can't initialize :

It looks like an i2c communication error but I've checked the i2c devices connected on the raspi it correctly detects the MPU ..

I don't know why I have this error... I must have missed something but I really don't understand what, could anyone help me please ?

Many thanks and best wishes,

Lilie