Calibrate internal 32khz RC oscillator using the 16MHz crystal?

[ray]

Is there an example code anywhere for the nRF51822 to calibrate the internal 32khz RC oscillator using the 16mhz crystal when not using the BLE stack/softdevice?

I would like to calibrate it every 4 seconds to meet the 250ppm tolerance as indicated in the datasheet.

Thanks, Ray

[Håkon Alseth]

Hi,

I've made a small example that shows how to do this.

Please see the attached zip file.

BR Håkon

rc_osc_calibrate_example_rev2.zip

[ray]

Thank you!

[Håkon Alseth]

There was a logic error in my code, where i did not check against == 0 in this line: while (NRF_CLOCK->EVENTS_DONE);

This should be "while (NRF_CLOCK->EVENTS_DONE == 0); Updated the .zip file with these changes.