How to send caps lock to ble keyboard from BLE HID dongle?

[panypan]

Hello,

Our customer use nrf52820 to make a ble hid dongle and the ble keyboard work well when connected to it. But when the keyboard is pressed the Capslock key, the led light does not change. If the keyboard is connected to the built-in Bluetooth of the PC that the capslock led will change. This indicates that there is no problem with the keyboard, but the dongle does not output the status to the keyboard. 

We found that there is an output event on the USB of the dongle side, but it is not sent to the keyboard through ble.

So my question is how to send this status to the keyboard?

thanks!

Best regards,

Pany

[panypan]

This code is based on sdk17.0.2 .

[Hieu]

Hi panypan,

I don't think Nordic provides any SDK support for HIDS Central/Host in nRF5 SDK. Is your customer making their own implementation of the HIDS Central with the dongle?

Hieu

[panypan]

Hi Hieu,

Yes, customer adds the ble central based on the examples "usbd_hid_composite" for the dongle. So do you have any methods and suggestions? Thanks!

Best regards,

Pany

[Hieu]

Hi panypan,

I think you misunderstood me a little here.

The dongle software/firmware in this case is (most likely) consisted of two parts. The HID part that talks to the computer, and the BLE Central part that talks to the keyboard.
From your following description:

We found that there is an output event on the USB of the dongle side, but it is not sent to the keyboard through ble.

I think the problem lies in some missing implementation in the BLE Central part.

Meanwhile, in nRF5 SDK, Nordic does not provide a HID Service Central library or example, I think your customer is implementing their own solution for the BLE Central part.

Therefore, I cannot provide a specific answer to you. Definitely not code.

However, I do find that in the nRF Connect SDK, Nordic does provide a HIDS Central example, where the Caps Lock event is sent. Your customer can refer to how they handle that to get the concept and replicate it in their implementation.
The sample source code and documentation can be found here: sdk-nrf/samples/bluetooth/central_hids at v2.1.0 · nrfconnect/sdk-nrf (github.com)

Best regards,

Hieu

[panypan]

Hi Hieu,

Thank you for your reply. Your suggestion is very good and I will let the customer follow your suggestions to achieve.

Best regards,

Pany