APP_TIMER_TICKS inverse calculation

[100401373]

Hello,

I would like to know the number on ms that a timer has been running before stopping in a breakpoint while debugging.

I can know the number of ticks with the following function: app_timer_cnt_get().

And the APP_TIMER_TICKS returns the number of ticks if you know the ms, but I want the opposite operation: know the time (in ms) with the number of ticks.

Thank you

[ovrebekk]

Hi 

The APP_TIMER_TICKS macro is defined in app_timer.h like this:

#define APP_TIMER_TICKS(MS)                                \
            ((uint32_t)ROUNDED_DIV(                        \
            (MS) * (uint64_t)APP_TIMER_CLOCK_FREQ,         \
            1000 * (APP_TIMER_CONFIG_RTC_FREQUENCY + 1)))

The opposite macro doesn't exist, but it should be possible to make one like this:

#define APP_TIMER_MS(TICKS)                                \
            ((uint32_t)ROUNDED_DIV(                        \
            (TICKS) * 1000 * (APP_TIMER_CONFIG_RTC_FREQUENCY + 1),\
            (uint64_t)APP_TIMER_CLOCK_FREQ))

Essentially you just have to switch around the divisor and dividend components, so that you multiply with 1000 * (APP_TIMER_CONFIG_RTC_FREQUENCY + 1), and divide by (uint64_t)APP_TIMER_CLOCK_FREQ. 

I haven't tested it myself, so use at your own peril ;)

Best regards
Torbjørn