How to handle Time Consuming Function Calls in Application Having SoftDevice?

[[email protected]]

Hello everybody,

I am working on a nRF52832 DK  and implemented libuarte (on a nRF52832) to communicate with another uC on said board.
I am using sdk 17.0.2. The goal is to receive data from the other uC and transmit it via BLE to a connected device using notifications/Indication via Characteristics.

I need To handle some state application handle functions that consume more time in execution. I'm not aware of where to call these functions, so that softdevice communication timing remain maintained.  Currently, I'm calling these functions in idle_state_handle(); and i'm not pretty sure that it is correct way to call here.

[Jørgen Holmefjord]

Hi,

The softdevice runs in interrupt context, in order to handle timing-critical BLE events. The softdevice will always have higher priority than the application, so the application will be preempted if the softdevice needs to handle its tasks.

See Interrupt model and processor availability and Scheduling for more details about how this works. Make sure that you call the time consuming function from main context, to prevent blocking softdevice or other peripheral interrupts.

In case you need to perform a task in the application without being interrupted by the softdevice, you can use the Timeslot API to request a timeslot.

Best regards,
Jørgen

[Jørgen Holmefjord]

Hi,

You will get an error from nrf_libuarte_async_tx() if you have already started one transfer, and you call the function again before the transfer is completed. You need to wait for the NRF_LIBUARTE_ASYNC_EVT_TX_DONE event in the event handler before calling this function again.

In general, you can build the application in debug configuration (or with DEBUG preprocessor symbol defined), and read out the error code and file/line that caused the error from the logger.

Best regards,
Jørgen