Electronics Architecture

This page covers only the signal side of the electronics. Power distribution itself is out of scope here — see Power & Battery.

Voltage domains

Rail	Source	Consumers	Parts crossed
12 V motors (9.6–12.6 V, straight off the battery)	battery	Leg servos, wheel gimbal motors (BLDC), SimpleFOC Mini drivers (one per wheel), Nano Every	legs, torso
6 V	reg.	Head servomotors, XIAO RP2350 (regulated directly by a HAT)	head
5 V	reg.	Raspberry Pi 5	main computer
3.3 V logic	reg.	Pico 2, sensors	legs

Regulator details live in Power & Battery.

Power tree

flowchart TB
    bat["Battery pack<br>9.6-12.6 V"] --> prot["Protection / switch"]
    prot --> r12["12 V rail"] --> legs["Legs & wheels<br>servos, BLDC, SimpleFOC Mini x2"] & nano["Nano Every"]
    prot --> r6["6 V rail"] --> head["Head<br>servos, XIAO RP2350"]
    prot --> r5["5 V rail"] --> pi5["Raspberry Pi 5"]
    prot --> r33["3.3 V rail"] --> pico["Pico 2, sensors"]

Switch

Coming soon.

Bus electrical characteristics

UART between the Pi 5 and the Pico is 3.3 V on both sides.

I2C between the Pi 5 (3.3 V) and the Nano Every (5 V) goes through a level shifter.

Still to detail: I2C pull-up values and placement, and reference voltage.