CM4 Pin Usage (GPIO, USB, Display)

I’m working my way through the uConsole schematics, and I’m just hoping to clarify a couple of compatibility things on the fringe of the system.

Where it’s ambiguous, I’m using references from the uConsole schematic, not the CM4 schematic.

  • The GPIO 40 pin connector will not support every pin, because there is a shortage of available GPIO from the CM4. For example, GPIO6 does not correspond to anything on the CM4, but GPIO5 should work fine.
  • The built-in display uses the CM4’s Display Serial Interface pins (DSI1_), not the HDMI pins.
  • The USB from the CM4 (USB_) is split four ways into the USB-A port, the keyboard, and two for the EXT port.
  • The data pins on the USB-C port (USB0_) do not correspond to anything on the CM4, but theoretically do for other cores.

Did I mostly get it right? What did I miss?

EDIT: It looks like a detailed explanation of the GPIO is available here.