RE: About NRF52832 PWM output accuracy and pin problem?

Sigurd — Mon, 30 Oct 2017 14:31:00 GMT

Hi,

That is correct. You need to start the HFCLK crystal oscillator with the TASKS_HFCLKSTART to get more accuracy in the PWM signal.
Some GPIO pins on the nRF52-DK are used for other things, e.g. LF-Crystal, buttons, leds. Pin 9 and 10 are used for NFC by default. See this page for a drawing.

creator — Mon, 30 Oct 2017 10:47:20 GMT

NRF_CLOCK->TASKS_HFCLKSTART = 1; while(!NRF_CLOCK->EVENTS_HFCLKSTARTED){}