There can be a few explanations for this:
Does your motor controller (ESC) have an on-off switch? If so, try flipping that
Some ESCs need to "arm". Try going to full throttle and back and see if that makes a difference
I'm assuming you have your battery plugged in ;-)
Try reversing the direction in the myconfig.py file
These battery charging messages are normal when the battery is charging.
What happens when you take the robot off the charger? Have you tried putting the robot into safe mode (b'\x80\x83') before sending commands? Have you tried either of the scripts on the iRobot STEM github repo?
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