RE: wdt accuracy

Jo-Jo — Thu, 12 Jun 2014 18:36:34 GMT

Unfortunately the boards I am working on do not have the 32hHz crystal installed, but using the synthesized 32kHz internal clock seems to make it work correctly.

Thanks for the help.

RE: wdt accuracy

Stefan Birnir Sverrisson — Thu, 12 Jun 2014 13:12:35 GMT

Yes I am seeing this too. However, you can overcome this problem by selecting the 32kHz crystal explicitly, then it should be accurate. Enable the 32kHz crystal with the following code before starting the watchdog timer:

NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_Xtal;
NRF_CLOCK->TASKS_LFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);
NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;