Nice to see. Are you planning to use 32 servos in the head, or is the plan to move one of the PCA9685’s to the body. I use one in the body and one in each arm. That makes the cable routing much easier and opens up for adding other i2c devices, like IMU, AD converters and other funn stuff. I have a few new i2c devices on my desk, waiting for me to have time to build services for them. One is a capacitive touch sensor control module (MPR121) and the other two are laser ranging distance sensors ( VL53L0X and VL6180X).

Hi Mats
The 32 servo connections over I2C will cover all the connections for eyes, neck, fingers with some to spare

I’m running with 20Kg PDI 6221-MG servos for the heavy duty lifting (biceps, shoulders, hip rotation).

Those particular servos don’t seem to play nice with the PCA9685.

It looks like it may be related to the guidance here on hooking up digital servos:
https://learn.adafruit.com/adafruit-16-channel-servo-driver-with-raspberry-pi/overview

So, I’m hooking those particular servos up to a separate servo breakout device with an Arduino Nano