After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

Kenneth — Mon, 25 Jan 2021 14:59:52 GMT

Hello,

From my understanding the master branch should now support more than one HID report may be enabled, can you give it a go?

Best regards,
Kenneth

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

Kenneth — Sun, 17 Jan 2021 19:49:41 GMT

They have started the work on this, I hope to have an update in a few days.

Best regards,
Kenneth

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

Kenneth — Mon, 11 Jan 2021 14:54:28 GMT

I have created an internal request, I will update the case as soon as I learn more.

Best regards,
Kenneth

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

helen — Fri, 08 Jan 2021 05:37:21 GMT

Yes, the code of NCS desktop is great, and its compatibility is very good. I can easily modify the code to adapt to different hardware or chips. The connection mode and pairing options are easy to modify. But I do see the code on hid_state.c in a daze. Yes, this code is so rigorous that I can't modify it.

My product needs to realize the keyboard function of the notebook, it needs a touchpad. It can be connected to a laptop or tablet, which makes it compatible with HID mouse and HID keyboard. The current firmware (1.4.0) is compatible with multiple HID devices, and only BLE connections are available.

Have you considered subsequently modifying the firmware to support compatibility with multiple HID devices? Because there are indeed customers who need this feature. This is in line with the original intention of NCS desktop, and the software can be configured according to the customer's hardware or needs without the need to modify too much code logic.

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

Kenneth — Thu, 07 Jan 2021 19:53:25 GMT

Combining mouse and keyboard is something that we have "missed" in ncs1.3, we have added the functionality to ncs1.4.0. In general the problem is in hid_state - we have assumed all reports will go to "separate" transports (by separate I mean each handling its own state).

The problem with usb in ncs1.3.0 is that it can send only one report at a time so there is no way you can send both mouse and keyboard report as hid_state will not know how to handle it.

I believe this fix may have been backported to ncs1.3 - you can see the backported changes here:
https://github.com/pdunaj/fw-nrfconnect-nrf/commits/DESK-1072

What you are interested in is:
https://github.com/pdunaj/fw-nrfconnect-nrf/commit/e4cf5d2af1f626d5e35ad0fc1ec0124996c63fd1

I recommend to have a look at all the changes - because some are fixing report descriptors to make them compliant. After you apply the fix the only thing needed to have mouse + keyboard reports on one peripheral device would be to enable these reports in kconfig.

There is however one thing to know - we still don't support multiple usb hid class instances for peripheral. That is hid_state will NOT handle this situation right and we believe this was the problem that you were experiencing when trying out ncs1.4.0.

Since there is all the code needed (I believe) to redirect reports (in hid_state) to different instances of USB HID class, this should be doable, but you still you have to add some logic to correctly select which instance to use as a selected subscriber for a given report.

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

helen — Thu, 07 Jan 2021 13:25:14 GMT

I tried for a few days and still couldn’t achieve the desired effect. I made the following changes:

usb_state.c

1.1 Modify usb_init usb_hid_device[1] as KEYBOARD and usb_hid_device[0] as MOUSE.

        usb_hid_device[0].dev = device_get_binding("HID_0");
	if (usb_hid_device[0].dev == NULL) {
		LOG_ERR("Cannot get USB HID 0 Device");
		return 0;
	}

	usb_hid_register_device(usb_hid_device[0].dev, hid_mouse_report_desc,   // hid_kbd_report_desc   hid_mouse_report_desc
				sizeof(hid_mouse_report_desc),&hid_ops[0]);

	usb_hid_init(usb_hid_device[0].dev);


	usb_hid_device[1].dev = device_get_binding("HID_1");
	if (usb_hid_device[1].dev == NULL) {
		LOG_ERR("Cannot get USB HID 1 Device");
		return 0;
	}

	usb_hid_register_device(usb_hid_device[1].dev, hid_mouse_report_desc,
				sizeof(hid_mouse_report_desc),&hid_ops[1]);

	usb_hid_init(usb_hid_device[1].dev);

2.hid_static.c

#define SUBSCRIBER_COUNT (IS_ENABLED(CONFIG_DESKTOP_HIDS_ENABLE) + \
              IS_ENABLED(CONFIG_DESKTOP_USB_ENABLE)+IS_ENABLED(CONFIG_DESKTOP_USB_ENABLE))

Modify hid_state struct to add an additional subscriber for usb_hid_device[1] (KEYBOARD).

struct hid_state {
    struct report_data report_data[INPUT_REPORT_DATA_COUNT];
    struct subscriber subscriber[SUBSCRIBER_COUNT];
    struct subscriber *selected;
        struct subscriber *selected_extra;//！！
};

handle_usb_hid_event｛
    if (event->enabled) {
        //if (!get_subscriber_by_type(true)) { //Multiple USB subscribers can be added
            connect_subscriber(event->id, true, 1);
        //}
    } else {
        disconnect_subscriber(event->id);
    }
｝

Assign the subscriber of MOUSE to state.selected KEYBOARD to state.selected_extra

connect_subscriber｛

static uint8_t usb_count = 0; // sean 1.6
  usb_count++;// sean 1.6
//				for (size_t j = 0; j < ARRAY_SIZE(state.report_data); j++) { //sean 1.6
//					struct report_data *rd = &state.report_data[j];
//
//					rd->linked_rs = NULL;
//					clear_report_data(rd);
//				}
                                  if(usb_count==1)
				state.selected = NULL;
                             
			}
                     
            if(usb_count == 2)
                  state.selected_extra = &state.subscriber[i];

			if (!state.selected ) {

                          if(usb_count==1)
                          {
                          state.selected = &state.subscriber[i];
                          LOG_INF("!! Active subscriber %p %d",state.selected->id,i);
                          }

			}
			...
｝

Used state.selected_extra at the time of sending keyboard report

send_report_keyboard
{
   ... 
    event->subscriber = state.selected_extra->id;
}

report_send{
    ....
     __ASSERT_NO_MSG(rs->subscriber == state.selected || rs->subscriber == state.selected_extra);
     
     
｝

Press the mouse, the mouse responds.

You can see that the code is executed to hid_int_ep_write

LOG print

usb_hid->dev = 0x20000f18; usb_hid_device[1].dev = 0x20000f00

Note: usb_hid_device[0].dev = 0x20000f18 (MOUSE)

Press the keyboard, No characters output on PC ！！！

LOG print

usb_hid->dev = 0x20000f00; usb_hid_device[1].dev = 0x20000f00

Note: usb_hid_device[1].dev = 0x20000f00 (KEYBOARD)

But report_sent_cb is not executed.

I tried many methods and I don't know how to modify it!

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

Kenneth — Mon, 04 Jan 2021 13:55:51 GMT

At the moment mouse will use only one and subsequent usb devices are simply ignored: https://github.com/nrfconnect/sdk-nrf/blob/v1.4.0/applications/nrf_desktop/src/modules/hid_state.c#L1381

And we have only one USB subscriber: https://github.com/nrfconnect/sdk-nrf/blob/v1.4.0/applications/nrf_desktop/src/modules/hid_state.c#L46. You have to create one additional subscriber per USB HID device.

Then when USB connects it should overtake reports it wants (at the moment it overtakes all): https://github.com/nrfconnect/sdk-nrf/blob/v1.4.0/applications/nrf_desktop/src/modules/hid_state.c#L488

Then module should allow different subscribers to use different reports at the same time (at the moment selected subscriber takes them all):

https://github.com/nrfconnect/sdk-nrf/blob/v1.4.0/applications/nrf_desktop/src/modules/hid_state.c#L1090

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

helen — Mon, 28 Dec 2020 01:15:05 GMT

I try to add HID mouse and HID keyboard device, and then connect the PC via USB.

I can configure the mouse or keyboard separately, but there are problems when adding them at the same time. In usb_init of usb_state.c

Set CONFIG_USB_HID_DEVICE_COUNT = 2

Set up
CONFIG_DESKTOP_HID_REPORT_MOUSE_SUPPORT=1

CONFIG_DESKTOP_HID_REPORT_KEYBOARD_SUPPORT=1

If usb_hid_device[0] is initialized to MOUSE, MOUSE is available, but KEYBOARD is not available.
If usb_hid_device[0] is initialized to KEYBOARD, KEYBOARD is available, but MOUSE is not available.

An error occurs when using usb_hid_device[1]. After report_sent, enter the report_issued of usb_state.c to report an error
LOG_WRN("No subscriber %p", subscriber_id);
Then MOUSE and KEYBOARD are not available.

It seems that the logic of the code does not support modification to support both KEYBOARD device and MOUSE device connected via USB.
So how should I modify it?
Is it convenient to use build_nrf52840dk_nrf52840 to simulate? I have tried many modifications but failed to achieve the effect, and support KEYBOARD device and MOUSE device at the same time.

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

helen — Mon, 21 Dec 2020 11:40:49 GMT

I tried 1.4.0 and adding CONFIG_DESKTOP_HID_MOUSE and CONFIG_DESKTOP_HID_KEYBOARD at the same time will cause the USB to not work. I need to know how to add two HID instances. I think I should take a look at Zephyr's USB example.

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

helen — Mon, 21 Dec 2020 11:40:40 GMT

RE: After NCS 1.3.0 nRF Desktop LLPM is disconnected, there is no data on the USB.

Kenneth — Wed, 16 Dec 2020 16:15:41 GMT

Hello,

Have you tried the latest v1.4.1 release?

Kenneth