RE: Disconnection right after connection established on nRF52805 using nRF Connect (BlueN

Simonr — Wed, 29 Jan 2025 11:49:20 GMT

Glad to hear you were able to get it up and running. If you need some sort of closure or root cause here, I'd recommend comparing the working and non working projects to see what the exact differences are. If not, I think we can close this ticket.

Best regards,

Simon

RE: Disconnection right after connection established on nRF52805 using nRF Connect (BlueN

Saar — Tue, 28 Jan 2025 13:03:42 GMT

Thanks a lot for the reply,

I tried this as well and many other things but nothing worked.

Eventually I re-ctreated the project from an example project, applied all changes to meet my board (BlueNor BC805) and that did the trick.

Saar.

RE: Disconnection right after connection established on nRF52805 using nRF Connect (BlueN

Simonr — Mon, 27 Jan 2025 11:13:31 GMT

This error message is a pretty generic timeout error, but I've seen it before, and more often than not when this occurs on custom boards, it is because the custom board does not have an external 32.768kHz crystal mounted.

If that's the case, you will need to make the following changes in your sdk_config.h file to use the internal RC oscillator instead. Make sure the following defines are set and try flashing the project again and see if you're able to connect then:

// <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

// <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

If that doesn't do it, please share some more details on what this custom board is exactly, and what SDK version you're using for development.

Please note that for new designs, we strongly recommend checking out the nRF Connect SDK, as the nRF5 SDK is now only in maintenance mode.

Best regards,

Simon