I have started getting an assert in my code while testing new functionality.
I am using SDK 17.1.0 and the nRF52840 DK
The assert is line 321 in app_timer2.c
/* If assert fails it suggests that safe window should be increased. */
ASSERT(app_timer_cnt_diff_compute(drv_rtc_counter_get(p_instance),
drv_rtc_compare_get(p_instance, 0)) < APP_TIMER_SAFE_WINDOW);
Looking at the the description of APP_TIMER_SAFE_WINDOW_MS in sdk_config.h
// <o> APP_TIMER_SAFE_WINDOW_MS - Maximum possible latency (in milliseconds) of handling app_timer event. // <i> Maximum possible timeout that can be set is reduced by safe window. // <i> Example: RTC frequency 16384 Hz, maximum possible timeout 1024 seconds - APP_TIMER_SAFE_WINDOW_MS. // <i> Since RTC is not stopped when processor is halted in debugging session, this value // <i> must cover it if debugging is needed. It is possible to halt processor for APP_TIMER_SAFE_WINDOW_MS // <i> without corrupting app_timer behavior. #ifndef APP_TIMER_SAFE_WINDOW_MS #define APP_TIMER_SAFE_WINDOW_MS 300000 #endif
Am I correct in thinking this means that this will assert if, for (1024-300) seconds, or ~12 minutes, the app_timer event is not handled?
If so, how do I go about debugging which timer isn't handled?
I initially saw this after leaving a board running for around 36hrs. I think I saw it again, didn't get the error log unforunately, after over 24 hours. I have tried to set up a test to replicate is and saw it withing 4-5 hours. It is still in sat in this state with the debugger attached but I don't know where to begin with working out the cause.
The debugger output is:
[03624616] <error> app: ERROR 3735928559 [Unknown error code] at nRF5_SDK_17.1.0_ddde560/components/libraries/timer/app_timer2.c:321 PC at: 0x000362B3 [03624623] <error> app: End of error report
I want to understand why this is occuring, why it isn't after a fixed period of time and whether increasing APP_TIMER_SAFE_WINDOW_MS is a fix or a bandaid.
