RE: turning on/off a LED by toggling a GPIO pin using a timer and PPI

felixgattiker@xrite.com — Wed, 21 Mar 2018 12:53:51 GMT

Hi, thanks for the quick help. I have implemented your code snippet, which resulted in a much more stable signal!

RE: turning on/off a LED by toggling a GPIO pin using a timer and PPI

Vidar Berg — Wed, 21 Mar 2018 12:49:01 GMT

Hi Felix,

The system use the internal oscillator by default (HFINT), which has a typical tolerance of +/- 1.5 % (max. +/- 6%). This probably why you are seeing the jitter. A solution is to request the HFXO from your application when higher accuracy is needed:

NRF_CLOCK->TASKS_HFCLKSTART = 1;

while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0;