Strange behaviour from custom board and SDK 14.2

[jumpingfool]

I have an application for the nRF52832 which is working fine on SDK 12.3 and I am trying to port it over to SDK 14.2.

After some tweaking I have got the application ported across and working fine on the nRF52 DK. However, when I flash it onto a custom board I see some really strange behaviour. The application seems to run but just really, really slowly - it takes maybe 10 seconds to complete initialisation and then seems to advertise about once per minute!

I've tried compiling the stock BLE examples provided in the SDK and see the same behaviour. Trying something simple like the (non-BLE) blinky application works fine.

If I suspend the execution on the debugger it breaks on a SEV opcode sandwiched between two WFE opcodes somewhere outside of my code.

Is suspect a clock issue but not sure why I would only see this with SDK 14.2 when SDK 12.3 works fine. I am using the internal RC in the board configuration.

Any suggestions on possible causes/resolutions would be appreciated!

[jumpingfool]

Ok, so I found the issue - the config for the clock source has moved from the board definition files to the sdk_config.h in the newer SDK::

// <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
#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