How do I run a long operation without disrupting a BLE link?

[syntroniks]

I am developing a BLE peripheral with SDK9 and SD110. The PPCP are 80-400ms, 5 slave latency and 5s supervision timeout.

I am currently running some blocking code in response to an alert level update (from IAS). The blocking code is manually driving a piezo element. I am placing that function on the scheduler queue in the hopes it would be pre-empted by the softdevice as needed. Unfortunately I am getting link loss as a result of updating the alert level.

Is there a way to make this work with my current setup? Or, do I need to use a different method? (At this time it seems like a timer would be an acceptable alternative, but I'm pressed for time and have not worked with 16MHz timers on this device yet)

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EDIT

Thanks all -- I ended up using TIMER1 and some clever code. Things now work acceptably. Previously I am fairly certain my code was executing in too high of an interrupt context. Now I don't care what the context is because the code returns nearly immediately.

[FormerMember]

When using the softdevice, the softdevice has the highest interrupt priority. Therefore, driving a piezo element will not block the softdevice. The Exception (interrupt) management with a SoftDevice chapter in the S130 softdevice specification shows the interrupt priorities used by the softdevice, and which interrupt priorities the application should use.