Configure external clock 32.768K

[Josh_1]

Hi

Please advise how to configure external clock instead using the internal.

Thanks

[Josh_1]

Hi,

I need to configure the SDK SoftDevice clock configuration to work with external Oscillator (square wave).

At the SDK below you can see just three "NRF_CLOCK" options to choose from and there is not LFXO rail to rail like you suggest.

Please advise.

Thanks

// <h> Clock - SoftDevice clock configuration

 

//==========================================================

// <o> NRF_SDH_CLOCK_LF_SRC  - SoftDevice clock source.

 

// <0=> NRF_CLOCK_LF_SRC_RC 

// <1=> NRF_CLOCK_LF_SRC_XTAL 

// <2=> NRF_CLOCK_LF_SRC_SYNTH 

 

#ifndef NRF_SDH_CLOCK_LF_SRC

#define NRF_SDH_CLOCK_LF_SRC 0

#endif

 

// <o> NRF_SDH_CLOCK_LF_RC_CTIV - SoftDevice calibration timer interval. 

#ifndef NRF_SDH_CLOCK_LF_RC_CTIV

#define NRF_SDH_CLOCK_LF_RC_CTIV 16 //0

#endif

 

// <o> NRF_SDH_CLOCK_LF_RC_TEMP_CTIV - SoftDevice calibration timer interval under constant temperature. 

// <i> How often (in number of calibration intervals) the RC oscillator shall be calibrated

// <i>  if the temperature has not changed.

 

#ifndef NRF_SDH_CLOCK_LF_RC_TEMP_CTIV

#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV 2   //0

#endif

 

// <o> NRF_SDH_CLOCK_LF_ACCURACY  - External clock accuracy used in the LL to compute timing.

 

// <0=> NRF_CLOCK_LF_ACCURACY_250_PPM 

// <1=> NRF_CLOCK_LF_ACCURACY_500_PPM 

// <2=> NRF_CLOCK_LF_ACCURACY_150_PPM 

// <3=> NRF_CLOCK_LF_ACCURACY_100_PPM 

// <4=> NRF_CLOCK_LF_ACCURACY_75_PPM 

// <5=> NRF_CLOCK_LF_ACCURACY_50_PPM 

// <6=> NRF_CLOCK_LF_ACCURACY_30_PPM 

// <7=> NRF_CLOCK_LF_ACCURACY_20_PPM 

// <8=> NRF_CLOCK_LF_ACCURACY_10_PPM 

// <9=> NRF_CLOCK_LF_ACCURACY_5_PPM 

// <10=> NRF_CLOCK_LF_ACCURACY_2_PPM 

// <11=> NRF_CLOCK_LF_ACCURACY_1_PPM 

 

#ifndef NRF_SDH_CLOCK_LF_ACCURACY

#define NRF_SDH_CLOCK_LF_ACCURACY 1  //7

#endif

[Simonr]

Hi Josh

How to set LFXO to rail to rail was described in the link provided in my last reply.

Best regards,

Simon

[awneil]

How to properly post source code:

[Josh_1]

Hi

maybe I miss something, How to configure the SoftDevice ,which type I need to choose?

 

// <0=> NRF_CLOCK_LF_SRC_RC 

// <1=> NRF_CLOCK_LF_SRC_XTAL 

// <2=> NRF_CLOCK_LF_SRC_SYNTH 

[Simonr]

NRF_CLOCK_LF_SRC_XTAL is the external LF clock.

Best regards,

Simon