pwm library continuous change with softdevice not working

RE: pwm library continuous change with softdevice not working

Vrabec — Sun, 15 Nov 2015 21:17:43 GMT

@Paweł Zadrożniak, Finally, I incorporate scheduler into my application. Unfortunately, problem with Disconnect after some period of time remains. Updated workflow is following:

scheduler and my core functionality is initialized in main.
When ble_event is received it's dispatched to my service.
Service checks send message (few bytes) it is propagated to HW.
When PWM function is required, I start timer 1 (timer was already initialized)
When timer IRQ happened, it schedules setting PWM value.
In while loop (main), scheduler is executed.

In general program works, but when I set continuous changing PWM from duty cycle 0 to 255 with step 4, it takes about 20 iterations till BLE is disconnected. Do you have any idea how to solve this issue?

RE: pwm library continuous change with softdevice not working

Pawel Zadrozniak — Thu, 12 Nov 2015 14:49:15 GMT

There was a lot of bugfixes and improvements, so I would recommend using app_pwm from SDK 10 anyway. Note that app_pwm requires some time to change the duty cycle (up to 2 periods). To make a change when PWM is busy, you have to wait until the previous operation is complete. Waiting in interrupt (BLE event handler or timer handler) blocks the execution of lower/equal priority tasks. App_scheduler is a good option here - task can be queued in interrupt and executed in app_sched_execute() from main context.

RE: pwm library continuous change with softdevice not working

Vrabec — Thu, 12 Nov 2015 14:10:23 GMT

actually, I tried app_pwm from SDK 9 and issue remains. In forum I find out, that pwm was not able apply changes, because I did it all in ble event handling which has higher priority. So current version I have (still not working like I want) is following:

based on ble event (after parsing) i set some parameters for pwm.
separate timer (initialized in main.c) check if this parameters was changed, and if yes, change pwm accordingly. Unfortunately with this approach I get ble disconnect event due general timeout. So far I don't found/implement any solution. Maybe scheduler will do the trick, but I have no experience with this stuff.

RE: pwm library continuous change with softdevice not working

Pawel Zadrozniak — Thu, 12 Nov 2015 14:02:18 GMT

Have you tried the updated app_pwm library from SDK v10 ( developer.nordicsemi.com/.../ ) ?