How much space do App Timers need?

[Branden Ghena]

I have a question about how much memory is required for app timers.

The comments for APP_TIMER_BUF_SIZE state that the buffer size must be one more than actually needed. Hence, the macro adds a +1 to OP_QUEUES_SIZE before calculating buffer size.

The definition for APP_TIMER_INIT creates the buffer, and calls APP_TIMER_BUF_SIZE((OP_QUEUES_SIZE)+1). Adding an extra +1 to OP_QUEUES_SIZE.

Is this a mistaken duplication of the extra space, or is there a reason APP_TIMER_INIT adds a +1 as well? I was looking through the App Timer documentation and it smells like a bug to me.

[Hung Bui]

Hi Branden,

I agree, seems like a mistake. I have reported this internally. I believe we only need to call APP_TIMER_BUF_SIZE(OP_QUEUES_SIZE) when in APP_TIMER_INIT.

Thanks for noticing.