Identifying the source of a callback defined with NRF_SDH_BLE_OBSERVER

[TomKeddie]

I'm working with S132, SDK15.0 and an NRF52832 defining custom services. 

I have two services with each with several characteristics.  I need to be able to determine which service and/or characteristic a NRF_SDH_BLE_OBSERVER callback is related to.  eg. when I get BLE_GATTS_EVT_HVN_TX_COMPLETE I need to know which service and/or characteristic to pass the callback to.

I've studied the parameters in ble_evt_t but I don't see something that will help me here, none of the handles seem to change between services or characteristics.  The void* is of no help because it applies to the instance of NRF_SDH_BLE_OBSERVER not the instance of the service or characteristic.

Thanks,
Tom

[OlaHallstrom]

Hi,

I'm certainly no expert in this area, but at least in my application, the different services register their own observer and direct callbacks to their own handler. Doing this way would solve your problem I think.

Regards

Ola

[TomKeddie]

Thanks but I don't think there is a way to define an observer for a particular service.  It's my observation that all observers are global and get called for all events.  There is no syntax I can see that would tie an observer to a particular service nor allow an observer to see which service (or characteristic) initiated the callback.

Observer X always gets the void* parameter from the declaration of X but this only tells you which observer is being called, not which service is notifying.   You can use a different function for each observer to achieve the same affect.

[OlaHallstrom]

Ok, but if you study the example, you can use the data supplied in the context. I was under the impression that context will be relevant to the service in question...

[TomKeddie]

Thanks but from my observation this is related to the observer not the service.  That observer will always be called with that pointer but it will be called for all ble events regardless of the service (with the same pointer).

[OlaHallstrom]

I don't want to copy paste the same thing that is already in the supplied example so I urge you to study that; steps 5 and forward. Unless I completely misunderstood you, that is what you are looking for.

[Kenneth]

Hi,

All events will be forwarded to the observers yes, so you will need to do "filtering" in the observers. For instance you may have passed the service/characteristic handles during initialization to the respective observers, so they can quickly ignore the event if it's not relevant. 

Best regards,
Kenneth

[TomKeddie]

Kenneth said:

so they can quickly ignore the event if it's not relevant. 

Thanks this is exactly what I want to do but I can't find any distinguishing features/handles in the event that is passed in to compare with.