RE: NRF52 enters WFE deadlock depending on power source!? Maybe a softdevice power management issue?

Krastanov — Mon, 28 May 2018 20:29:13 GMT

Hello, Bjorn,

This was indeed the source of the issue. I was using the defaults for the Nordic dev board config, not anything modified for the BL652.

Originally it was

// <0=> NRF_CLOCK_LF_SRC_RC 
// <1=> NRF_CLOCK_LF_SRC_XTAL 
#define NRF_SDH_CLOCK_LF_SRC 1

The only change I made after your suggestion was

// <0=> NRF_CLOCK_LF_SRC_RC 
// <1=> NRF_CLOCK_LF_SRC_XTAL 
#define NRF_SDH_CLOCK_LF_SRC 0

#define NRF_SDH_CLOCK_LF_RC_CTIV 16

This still does not really explain why it was working fine with a certain power source and not working with all the other power sources, but it does not really matter - I should not have expected it to work at all.

Thanks for the help!

RE: NRF52 enters WFE deadlock depending on power source!? Maybe a softdevice power management issue?

bjorn-spockeli — Mon, 28 May 2018 14:06:54 GMT

HI Krastanov,

when the application code is hanging at sd_softdevice_enable(), then its usually due to the wrong LF clock source being configured. It appears that the BL652 does not have a 32kHz crystal so I could be that the SoftDevice is waiting for the LF clock to start up. Could you post the clock_lf_cfg configuration you're using?

Best regards

Bjørn