Issue description – USB communication failure between Raspberry Pi Zero 2 W and BTT Octopus Pro

[astral rampart]

USB issue: Pi Zero 2 W ↔ BTT Octopus Pro v1.0.1

I can’t get USB communication between a Raspberry Pi Zero 2 W and a BTT Octopus Pro.

Verified:

Pi is fully working, stable 5V ≥2A (iPad charger), vcgencmd get_throttled = 0x0

Octopus MCU flashed successfully via DFU, LED behavior changed as expected

Correct ports used (Pi USB/OTG, Octopus USB-C MCU, not USB-A)

Multiple data cables tested (incl. USB-C ↔ Micro-USB “charge & sync”)

24V ON, BOOT0 removed, USB-power jumper removed

Mainsail/Klipper installed correctly(i think)

Issue:
-lsusb only shows Linux Foundation 2.0 root hub
-No USB enumeration, no STM32/CDC device, no USB events

Any ideas on further diagnosis? Appreciated 🙏

[whole echo]

I would first check the settings used to build the klipper firmware that has been flashed to the octopus. There are different variants of the octopus board and they need to be correct for the board you have.

[proven glade]

if you are satisfied that the menuconfig settings are correct then there may be something else at play

there is a bug with pi3 (and by extension pi zero2w as it uses the same SOC) and certain peripherals. you can try running this command to remedy it:
echo 'dtoverlay=dwc2' |sudo tee -a /boot/firmware/config.txt

[astral rampart]

Thank you, menuconfig is correct. It seems the USB signal never gets to its destination. I tried the dwc2 thing and the problem remains.

[proven glade]

is there any reason you're using a zero2w, out of interest?

[astral rampart]

Not really 🙂 it’s just what I had at home.
At this point I’m fairly certain the issue is the Micro-USB → USB-C cable I’m using.
When I connect the Octopus directly to a PC using USB-C ↔ USB-C, it enumerates immediately (Windows beep).
But when I connect the Pi Zero to the PC using the same Micro-USB cable, there is no beep. Might have to buy a third cable to continue diagnosing this issue.

[proven glade]

i would say my experience with usbC to micro usb cables has been patchy at best

it might be worth exploring a usb hub adapter

[whole echo]

It just occurred to me that the pi zero's USB port is OTG. You'll need a specific cable for the zero to act as USB host.