USB-C based touch display - touch data signal path

[Jester]

I'm collecting components for a LinuxCNC based CNC lathe conversion.

I already have a RaspberryPi 4, and I loaded LinuxCNC on it.

Not a lot of space, so I'm thinking of using this touchscreen: https://www.amazon.ca/dp/B0CP3NTK2T?ref=ppx_yo2ov_dt_b_fed_asin_title

The preferred  way to connect this display is with a USB-C port that is used for all data; video, audio and touch data. However the PI does not have a USB-C port, it does have 2x USB-A 3.0 ports and HDMI.

The HDMI port works fine for the display, however the touch data is not working. The display pamphlet states that you need to use a full featured USB-C port to get the touch data back to the PC.

Looking at the USB-C pinout, it's not obvious what signal path they would use for the touch data:

It seems unlikely it's the D+, D- pair because using a type C to type A cable does not work as well as the note about the requirement for a "full featured USB-C port"

So it seems logical they are using the TXn, RXn data path, thoughts?

So now I'm wondering if using one of those USB-A 3.0 to USB-C adapters, one like this: https://www.amazon.ca/gp/product/B0DCC1M97C/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

would get the touch data back to the Pi?

[ataradov]

They are not going to be using anything non-standard. It should just enumerate as a HID device. Check 'dmesg' output on the Pi when you connect the cable and see how it enumerates.

By  "full featured" they likely mean Thunderbolt 3 capable, which will use TXn/RXn lines.