Disable HID some of the time

[nrbrook]

We are developing a device that has different "modes", and in some modes it acts as a HID keyboard and mouse, but in other modes it does not. This device connects to iOS and android, and in HID modes causes the virtual keyboard to be hidden as it is a HID keyboard. So in none-HID modes we want to avoid iOS recognising the device as a HID keyboard.

We have an existing device on a different platform which already implements this. When switching between HID and non-HID modes, it will modify the HID report and send a services modified indication for the HID service, causing iOS to re-read the HID report. This works fine.

What would be the best way to do the same thing on Nordic nRF52832? I've read that the GATT database cannot be modified without disconnection, which we want to avoid. Is there any way to do the same as on the existing platform – modify the HID report and send a services changed indication?

[Simonr]

Hi Nick

I don't think this will be attainable without disconnecting due to the modification limitation you mentioned. We can send a service indication, HID report, etc. but disconnecting and reinitializing the SoftDevice with the new attribute table will be necessary.

Best regards,

Simon

[nrbrook]

Ok thanks, so there is no way I can force a service changed indication to be sent?

[Simonr]

I asked around in the support team, and as far as we know, and based on what I've seen in various posts on Devzone. No, there isn't. Although I don't see why disconnecting between these "modes" would be a problem, when bonded, the device should be able to reconnect automatically after the reinitialize.

Best regards,

Simon

[nrbrook]

It isn't as fast, and we have our own services which would be interrupted by disconnection which then requires rediscovery on reconnection. If going from non-HID to HID mode, bonding would not exist as bonding will not be required in non-HID modes.

[nrbrook]

Actually there is the function 

sd_ble_gatts_service_changed

You can pass a start handle and end handle. The start handle of the service is provided when creating. How can I get the end handle? Or perhaps I can just pass 0xFFFF if the service is the last service to be added?