
1 Oct
2022
1 Oct
'22
12:21 a.m.
See https://github.com/hathach/tinyusb/blob/master/examples/device/cdc_msc/src/u... for an example of such a device. It has one mass storage device and one CDC. Changing the device class to 0x00 breaks support on Linux and macOS (I didn't try Windows).
The question is -- does the aforementioned device conform to the USB-IF specification ? I think it does not, but luckily it could be fixed in software on the tinyusb side.
I'm not familiar enough with the available USB specs to say what is "right" but I think the problem is that "fixing" it by changing the device class breaks support on major operating systems.