For a side project I was planning on using a connector with about 20 lines/pins and as small as possible. The USB-C popped into my mind since it contains many lines (24), it's very cheap nowadays and is readily available everywhere.
And tested the conductivity between the different lines when using two of these breakout boards at both ends and a standard? USB-C cable (one used also for data transfer, so I know it is not only power). It seems that I get electrical conduction only between GND pins on both ends and between the VBUS pins. I also put a sine throug the VBUS line and it seems heavily filtered.
I was already aware of the existance of some sort of front-end conversion chip present in many? all? USB-C cables, so I suspect that without that chip being powered up thanks to the voltage usually present in VBUS, the rest of the lines are "blocked". Is that assumption correct?
If that is the case, the other question would be... is there any usb-c cable that would allow me to use it in the way I want? Some sort of "just-the-lines" USB-C cable.