S132 vs S140

[Siv]

Is there any difference between S132 and S140 ble gatt handles.?

[bjorn-spockeli]

Hi Siv,

if you are referring to the GATT service that our SoftDevices automatically add to the GATT table, then it should be identical if the BLE stack configuration is identical, i.e. you add the Service Changed Characteristic.

The GATT handles of any BLE services/characteristics/descriptors added by the application will be determined by the order they are added. 

Beste regards

Bjørn

[Siv]

Hi bjorn,

 have added 4 characteristics in a single service in nrf52832 DK board which act as a peripheral device and nrf52840DK as a central device to discover the same services.After establishing connection data base discovery is finding all but while sending data only any two characteristics data is coming and remaining is missing.

If reset the peripheral device then at that time it is receiving all the characteristics data,is there any reason for that why it is missing some handles while sending data?

[bjorn-spockeli]

Siv said:

After establishing connection data base discovery is finding all but while sending data only any two characteristics data is coming and remaining is missing.

 Ok, so the nRF52840 discovers all four characteristics, but once you enable notifications on these characteristics you're only getting notifications from two out of four characteristics? Is this correct?

Siv said:

If reset the peripheral device then at that time it is receiving all the characteristics data,is there any reason for that why it is missing some handles while sending data?

So resetting the device so that the nRF52840 Central reconnects to the nRF52832 and performs a new service discovery solves the issue? Is the NRF52832 peripheral bonded with the NRF52840 central?

[Siv]

Ok, so the nRF52840 discovers all four characteristics, but once you enable notifications on these characteristics you're only getting notifications from two out of four characteristics? Is this correct?

YES..

So resetting the device so that the nRF52840 Central reconnects to the nRF52832 and performs a new service discovery solves the issue? Is the NRF52832 peripheral bonded with the NRF52840 central?

YES..

[bjorn-spockeli]

Ok, have you verified that the nRF52840 is writting to the correct handles, i.e. CCCD of the characteristics. Have you tried printing the  handles that are received during service discovery and then comparing these with the handles used to write to the CCCDs? 

You could also verify this by doing a on-air trace of the communication between teh nRF52832 and the NRF52840 using the nRF Sniffer, see https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Sniffer-for-Bluetooth-LE. 

So the nRF52832 is bonded with the nRF52840`?

[Siv]

Ok, have you verified that the nRF52840 is writting to the correct handles, i.e. CCCD of the characteristics. Have you tried printing the  handles that are received during service discovery and then comparing these with the handles used to write to the CCCDs?

Ans:Yes, i have checked the handles during data base discovery it is printing.In my example i have got handles as 12,15,18,21 respectively during discovery after that while sending data on hvx only 12 and 18 handles are matching with the existing ones.Remaining two are missing.

So the nRF52832 is bonded with the nRF52840`?

yes.

You could also verify this by doing a on-air trace of the communication between teh nRF52832 and the NRF52840 using the nRF Sniffer, see https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Sniffer-for-Bluetooth-LE. 

I will verify that and get back to you.

[bjorn-spockeli]

Ok, I will wait for the on-air trace. It would be usefull if you could capture the trace without bonding as I will not be able to see the content of the packets when they are encrypted. 

Best regards

Bjørn