piezo buzzer has to generate sound until event occurs

RE: piezo buzzer has to generate sound until event occurs

DMS — Thu, 04 Jan 2018 05:51:34 GMT

i am trying to dinit and the init of pwm after changing frequency, is this correct method.

RE: piezo buzzer has to generate sound until event occurs

Kyle Krueger — Tue, 02 Jan 2018 13:52:30 GMT

Ok, frequency would be controlled by how often your timer event fires.

RE: piezo buzzer has to generate sound until event occurs

DMS — Fri, 22 Dec 2017 05:13:21 GMT

Sorry i was talking about frequency

RE: piezo buzzer has to generate sound until event occurs

Kyle Krueger — Thu, 21 Dec 2017 14:39:40 GMT

I am not following you; duty cycle is typically a variable in PWM.

RE: piezo buzzer has to generate sound until event occurs

DMS — Thu, 21 Dec 2017 13:29:00 GMT

i could successfully change duty cycle , i got struck in pwm

RE: piezo buzzer has to generate sound until event occurs

Kyle Krueger — Wed, 20 Dec 2017 14:36:55 GMT

Any luck with this design change?

RE: piezo buzzer has to generate sound until event occurs

Kyle Krueger — Tue, 19 Dec 2017 14:42:28 GMT

It is possible to have more than one timer, but I wouldn't recommend setting up and tearing down a timer within another timer.

You should be able to just change your interval and increment the PWM setting on each call of the timer event.

Finally, you could stop the timer when the max value is configured, and set it back to the starting one.

RE: piezo buzzer has to generate sound until event occurs

DMS — Tue, 19 Dec 2017 14:36:23 GMT

can i use two timers ?

RE: piezo buzzer has to generate sound until event occurs

Kyle Krueger — Tue, 19 Dec 2017 14:22:04 GMT

I expect this is due to both the timer having too high of a priority and the for loop being a rather long callback in the timer. This might be causing a timeout in the BLE stack.

First check the priority of your timed event, and try setting it to 5 or lower. Second, try removing the for loop from your code too, and instead increment the value in each timer event.

P.s. this might be justified as a second question.

RE: piezo buzzer has to generate sound until event occurs

DMS — Tue, 19 Dec 2017 12:17:34 GMT

I am trying to replace while loop with timer, i have used simple timer example as reference. due to some reason connection is getting disconnected. What shall i do?

RE: piezo buzzer has to generate sound until event occurs

Kyle Krueger — Fri, 15 Dec 2017 12:16:17 GMT

Yeah, depending on your use case you can start and stop it where needed. The timer then replaces the while loop where the deadlock is hit.

RE: piezo buzzer has to generate sound until event occurs

DMS — Fri, 15 Dec 2017 10:57:13 GMT

event is triggered from application, u mean to say :- start timer when event is triggered from mobile application and stop timer when request to stop from mobile app. ?

RE: piezo buzzer has to generate sound until event occurs

Kyle Krueger — Fri, 15 Dec 2017 10:07:58 GMT

It looks like your event has a lower priority than the while loop.

If this is the case, you have an architecture problem. You could use the quick and dirty fix of moving this loop to a lower priority, but I would recommend some extra changes.

My suggestion would be to set up the buzzer on a timed event with low priority. You can turn on this timed event where you see fit, and turn it off in the event you are waiting for.

Again, the priority of your event should be higher than that of your timer.