Nordic NRF52840: Bluetooth Central HIDS Error

[2songh]

Zephyr Version: 3.4.99
Board: nrf52840dk_nrf52840

Use Sample: zephyrproject/zephyr/samples/bluetooth/encrypted_advertising/central

I would like to use the NRF52840 board as a central device to connect a bluetooth HID keyboard to it.

procedure

1. west build -b nrf52840dk_nrf52840
2. west flash
3. NRF52840 Booting
4. Start scanning for nearby Bluetooth devices
5. Bluetooth keyboard advertising starts
6. Connecting boards and keyboard
7. Check passkey
   
8. Click Button1 on the NRF52840 board
9. Security Change
   
10. LED output from my Bluetooth keyboard to indicate normal connection
11. Error message output from NRF52840 board
    

Errors occur in gatt_read() & gatt_read_cb().

Is it a GATT settings issue?
Or is there a problem with HID service function support?

Please give me advice regarding Bluetooth HID.

[hermabe]

I am not sure what you are asking here. The Encrypted Advertising Data (EAD) sample has a central and a peripheral part and they are made to be used together. They will not work with a different sample that is not made to use EAD. As far as I know does BLE HID not use EAD.

The error code is BT_ATT_ERR_INVALID_HANDLE which is probably caused by the GATT server (on the peripheral) not having the custom GATT service with key material.

[2songh]

I have additional questions.

Isn't EAD only used for the Bluetooth advertising function?
Is EAD also used when reading Bluetooth keyboard data?

I'm wondering if it's possible to only use EAD for Bluetooth advertising, and then receive HID data afterwards.

[hermabe]

EAD is encrypted advertising data and is as such only used for advertising. HID reports are sent over a connection which can be both encrypted and unencrypted.

[2songh]

Create a connected state after advertising,
Need to connect and communicate with HID reports?

[hermabe]

HID reports are sent over connections yes. Please read the documentation for the samples (eg. https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/central_hids/README.html).

If you are not familiar with how Bluetooth LE works I suggest you read up on it.

[2songh]

Thank you for your advice.
I will conduct additional test.