sd_ble_gatts_value_set

[DR_MC]

Hi

We use the function "sd_ble_gatts_value_set()" for setting new values of a characteristic(not changing the length). This function takes between 120 and 260 us time to be executed (Used Pin toggling before and after the execution). This execution time seems to be very long as we should be able to update several values within a 1-ms loop. Is this due to some mis-configuration? How could we speed up the execution time when updating a characteristics value.

We use a recent Softdevice 6.1.1 version and the characteristics are stored in the stack memory area (BLE_GATTS_VLOCK_STACK). 

Regards

Martin

[Kenneth]

Can you repeat measurement on \nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral\ble_app_hrs (battery measurement update) just to rule out any other application specific interrupts in your application.

Kenneth

[DR_MC]

Hi
I tried that measurement and it took 64 us (Battery Level update). (In my first post the Softdevice is wrong, we use 7.0.1 -> therefore i took the measurement with the new SDK 16.0.0_98a08e2). In our application we have a lot more characteristics registered. Could this be a reason for the time difference?

As we want to update some values (>10) in a 1 ms timeframe this duration is also too large for us. Is there a faster way of updating characteristics values?

regards

Martin

[Kenneth]

If you are not modifying the length field, then you should be able to place the value in application space (use BLE_GATTS_VLOC_USER) and modify it directly as discussed here:

https://devzone.nordicsemi.com/f/nordic-q-a/934/how-to-use-ble_gatts_vloc_user/4491#4491