NRF52840, Can USB CDC and USB HID work simultaneously?

[jwcheon]

Hi,

I am working on one project.

The background I use now is using SDK14.1 and SDH version 5.0.0-2. The tool is using Keil.

I wonder if I can use two USB descriptors via one USB. My goal is to work with CDC and HID at the same time.

I referenced APP_USBD_CORE_DEVICE_DESCRIPTOR in app_usbd_core.c.

In the last line,

---

.bNumConfigurations = 1 / * Fixed value: only one configuration supported * /

---

It is said. So I guess the USB descriptor seems to be unrecognizable.   But is there a way that both can work together?

Thank you. Best wishes for a Happy New Year.

[RK]

num configurations just says how many configurations there are, and you only need one. Please look up USB composite devices which allow you to have multiple interfaces under one configuration, that's what lets you have a CDC and HID working at the same time (as long as you have enough endpoints to support them)

[ovrebekk]

Hi

I can attest what RK is saying. You can combine multiple USB classes with only a single descriptor.

The usbd_hid_composite example in the SDK shows you how to do this (it combines two different HID classes, but the principle is the same for HID and CDC).

Best regards

[jwcheon]

Hi,

Thank you both for your reply. The answers you gave me seem to help me.

Let's try checking usbd_hid_composite example. I will contact you again if you have any difficulties. Thank you.

[ovrebekk]

Good luck :)

If you are still having issues after trying it out you know where to find us ;)

Best regards
Torbjørn