How to get 36 kHz or 38 kHz clock out from nRF52832 and/or nRF52840 chips ?

[Hannu Hirvonen]

Hi,

My question is quite easy. I need to use 36 or 38 (maybe something else frequency as well) kHz clock in our device. How it is possible or is this possible at all ? I'm using both nRF52832 and nRF52840 chips.

Br,

-Hannu-

[cbd]

Is this output going to be used to clock another device?

You won't be able to change any of the internal clock frequencies, especially if you plan on using BLE.

You can get close with the PWM generator (approximately 37KHz and 38.5KHz), but that will only give you a positive signal with square edges.

[Hannu Hirvonen]

Thanks for quickly answer :) This is aimed to be output clock for external components/device. Do you have examples for PWM somewhere ?

[Einar Thorsrud]

Hi,

Another alternative is to use a TIMER instance to control a GPIO pin via PPI, which is demonstrated by the GPIOTE Example. (You can look at the PWM Driver Example if you PWM peripheral instead as suggested by cbd).