DTM does not work when using the internal RC oscillator.

[moon.kim]

I am using S112 6.0.0 / SDK 15.0.0 for nRF52810.

I decided to use an internal RC oscillator to reduce parts.

However, after changing the setting to LFRC, DTM does not work.

#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
#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
#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
#endif

When using an external crystal, the DTM works well, but when using an internal RC oscillator, the DTM does not work.

DTM refers to the example code provided by Nordic.

In DTM mode, do I need to change the clock to use the internal RC oscillator?

[Jørgen Holmefjord]

Hi,

As far as I can see, the DTM firmware does not use RTC or the LFCLK in any way. The clock configuration should not affect the DTM. 

Can you explain in more detail what is not working with the DTM in your device?

Best regards,
Jørgen

[Jørgen Holmefjord]

Still not sure I understand your issue. Are you disabling BLE and the softdevice before you start the DTM module? Have you debugged the application when you send the DTM command, to see if it gets stuck somewhere?

Can you post the full project? That would make it easier to see how you integrated the DTM module, and try to reproduce the issue on our end.