Service Changed characteristic for multiple connections

[Muniek]

Hi, iOS caches services and characteristics when bonded with device, so we need to inform him to invalidate this information via Service Changed characteristic, but how it works for multiple connections? Does device will remember which device was already informed and inform only new connected devices? Or it will send notification for every device on new device connected? Thanks, Muniek

[endnode]

That is like theoretical question for "any" device? If so then answer obvious is: who knows, it will depend on how well developed the FW is on that device. Or are you asking in context of some nRF5 SDK example? Which one? Which SDK version?

In general each connection is separate business so GATT Server should treat each Client separately. If these two devices are bonded then - as requested by BT SIG spec - server must track the state of things such as CCCD handle values and sounds logical (might even be requested by the spec? Who knows, it has almost 3000 pages;) that it will track also entire state of GATT Server handle space and GATT Service Changed notifications.

[Muniek]

it's SDK 13 and nRF52832

[endnode]

Okey. But how exactly you implement multi-connection GATT Server? Do you use peer manager or any other SDK module or you manage that by your own state machine? Do you keep state of GATT Server for bonded devices in flash? So many questions... (and usually by answering them you will also answer your original "problem")

[Muniek]

Our first idea was to implement our own handling but if such a functionality already exists in peer manager we would probably start using it.