Improving the ADC

[sraillard]

The low level code, running on RPI Pico, is reading 3 analog values:

• Battery voltage
• Power voltage
• Battery charging current

The ADC seems to be noisy, using a moving average on 10 samples should improve the stability of the measures.

Also, I would be great if ratio can be configured (using UART commands) so calibration can be done for these 3 values (right now, the ratio are fixed in code, and I can observe a noticeable difference in voltage reading, this is especially important for monitoring the battery voltage).