handler event synchronous

[hongpal]

Hi

I am making a speed cadence sensor. I am using the gpio event handler to check the cumulative wheel revolutions and send the recorded value to the app as a time handler. But I wonder if there is a synchronization problem between the two events here. I am sorry for my poor English skills. I would appreciate your reply.

[Hung Bui]

Hi,

What exactly the issue you are thinking of ? My understanding is you use the GPIO event and trigger a counter (you can do it with PPI without CPU needed). And then you send the value of the counter on each timer timeout event ?

[hongpal]

Yes, that's right. You understand exactly.

[Hung Bui]

Yes, but what is the problem ? I don't see any problem here.

[hongpal]

Are the two events sharing the same counter value and not having synchronization issues? gpio events can occur from time to time and timeouts occur every second.

[Hung Bui]

No, you need to use one extra timer. So say TIMER1 you use as normal timer, trigger every 1 second, and TIMER2 use it as the counter and connect it to GPIO.