ANCS service migration

[skulkarni]

Dear Team,

I am migrating the ANCS client application from SDK-12.3 to SDK-15.3 version.

Please find my below observations in SDK-15.3.

Erase the flash completely and load the the  firmware  [ Using the ANCS client service code available in SDK-15.3 version]

Erase the phone bonding info in the IPhone.

<1> Pair the Iphone. <Success>

<2> Will make call to the Iphone and I could see the notification. Fetch the attributes of the notification. Print it on the console. <Success>

<3> Now restart the device <NRF52832>

 -->IPhone automatically gets connected.

--> I could also see that ANCS Database discovery also success.

--> Prints the notification messages [Missed call log]

<4>Now make a call to IPhone

 --> I could see the notification in the log, and attribute request for the notification is in progress.

 -->  Now I could see BLE_GAP_EVT_DISCONNECTED is received in the event handler.

Note: In SDK-12.3 the above mentioned scenario works perfectly fine.

Please let me know if you have any suggestions.

[skulkarni]

We have Android app also for which I didn't observe this behavior.

 My NRF sniffer [using the DK-NRF52832 board] works for android phone but for IPhone I am not able to capture the Airtrace.

[skulkarni]

6330.ANCS_Issue.pcapng

Hi Today I was able to take the sniffer log. I could see Terminate event from Iphone stating unacceptable connection parameters.  Please let me know why I am receiving this event.

Thanks,

Kulkarni

[Vidar Berg]

Thanks for providing a sniffer trace. I will take a look at it and also see if I can replicate the issue here. In the meantime, please make sure you're following the connection parameter recommendations given in section 25.6 of the Accessory Design guidelines document: https://developer.apple.com/accessories/Accessory-Design-Guidelines.pdf

Regards,

Vidar

[skulkarni]

ANCS_Terminate_User_connection.pcapng

Hi Vidar,

After repairing Iphone sends terminate connection after some time.

Please let me know if you get a chance a look into this issue. 

I could see from the slave(NRF52832) when ever connection parameter update request sent Iphone sending terminate signal.. ANCS_Conn_param_update.pcapng 

[Vidar Berg]

Hi,

I haven't been able to replicate the disconnect here. I'm testing with an iphone 8 running iOS 13.3. Could you try to update iOS if you're not on the latest version already? I don't think the "unacceptable connection parameters" response you got earlier was valid because the packet was malformed. Also, is it only missed calls that lead to disconnects, or do you see the same if you send a text message?

[skulkarni]

Hi Vidar,

I was storing the ANCS handles into persistent memory but when connecting to the  previously bonded device instead of reading from the flash I was again trying to get the handles by starting the DB discovery. Now I have removed the code to store the ANCS handles in the persistent  memory.

After this changes I am not seeing reconnect issue after connecting to previously bonded device.

I would like to understand the side effects of storing the handles in the persistent memory and doing the DB discovery again for the bonded device. 

[Vidar Berg]

Hi,

The only drawback is that you will need to perform service discovery on every connection even if the attribute table didn't change. So it adds a bit of overhead. But you don't need to store attribute handles to flash if you're doing the DB discovery anyway. Then you can just disable attribute caching.