Using soft device on custom board with nRF52840

[bojan]

Hello guys,

I am using SDK15.3.0 and BL654 modules containing nRF52840 on my custom board. In addition to that, I have both nRF52-DK and nRF52840-DK boards. I can program my custom boards through P19 connector, there is no issue with that. When I program my custom board with the code which does not contain SoftDevice but only uses some peripherals (e.g. I2S, timers...), everything goes smooth. I am able to program it through P19 connnector and to debug it with Segger Embedded Studio (to read NRF_LOG_INFO prints on Debug Terminal).

The problem arrives when I want to use SoftDevice. I started with examples/ble_peripheral/ble_app_template example on nRF52840-DK board. By following your great tutorials, I was able to create some custom services and characteristics as well as to connect with nRF Connect tool through nRF52840 dongle and exchange data. When I download the same code on my custom board and start debugging with Segger Embedded Studio, everything freeze and I can't see my custom board on nRF Connect. Call Stack is empty! I am loading SoftDevice S140 v6.1.1 together with my application through Segger Embedded Studio, like described here. Using nRF Connect Programmer tool, I was able to see memory layout of nRF52840 on my custom board and I can withness SoftDevice is there.

I am wondering from where comes this issue? What I am missing here?  Did someone of you guys run into the same issue?

Thank you very much for your time and effort.

Sincerely,

Bojan.

[awneil]

Does your custom board have a 32KHz crystal ?

https://devzone.nordicsemi.com/f/nordic-q-a/46564/error-133-0x85-gatt-error-on-nrf52840/185362#185362

[Ali Rumane]

Hi,

Did you set Low Frequency Clock settings correctly?

I faced similar issue  with BLE examples which was solved by setting clock source & settings correctly.

Regards

[bojan]

Hi awneil, thanks for replying. I am using BL654 module on my custom board. Accordng to chapter 5.17 on page 34 (link), external 32.768KHz oscillator is optional (not required for normal BL654 module operation). 

[bojan]

Hello Ali Rumane, thank you very much for your pointer! It was really useful for me! Indeed, I had the issue with SoftDevice clock configuration in sdk_config.h file. With the following settings everything works great:

// </h> 
//==========================================================

// <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

// </h> 

Thank you both, awneil, Ali Rumane, for your great feedbacks. I can now move forward!

Cheers,

Bojan

[awneil]

Did you read the linked post?

Yes, the external 32KHz is optional but, if you opt to omit it, then you have to configure your code accordingly.