secure_bootloader_ble nrf52811 custom board

[grosdode]

Hello,

I try to upgrade my project from NRF5 SDK 15.3 to 17.0. I like to begin with the bootloader, therefore I followed the steps from

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v17.0.2%2Fble_sdk_app_dfu_bootloader.html&cp=7_1_4_4_0

at the end I was able to flash the secure_bootloader\pca10056e_s112_ble to the pca10056e and also connect to it via BLE. Then I followed the steps from “Transferring emulated project”

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v17.0.2%2Fnrf52811_user_guide.html&cp=7_1_5_1

to flash it to my custom board with a NRF52811-CAAA. Flashing was no problem but I’m not able to find it via BLE.

The board works fine with the old secure_bootloader from NRF5 SDK 15.3.

[Vidar Berg]

Hello,

Please confirm if you have the optional 32 KHz crystal mounted on your board. If you do not have this crystal, you need to make sure you have selected the internal RC oscillator in your sdk_config.h file.

Configuration settings for selecting internal RC clock

// </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

[grosdode]

Hello,

No, I don’t have the optional 32 kHz crystal mounted but I had changed the settings

#define NRF_SDH_CLOCK_LF_SRC 0	// RF_CLOCK_LF_SRC_RC 

I played around a bit with this settings and the following seams to work fine.

// </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 2
#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 0
#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 0
#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 7
#endif

[Vidar Berg]

When selecting the RC oscillator, please note that you also need to change _CTIV, _TEMP_CTIV and ACCURACY as shown by the configuration I posted else you will get an assertion when trying to enable the Softdevice.

The SYNTH source is not low power as it will keep the HFXO on even when in System ON Idle mode.

[grosdode]

I thought I changed all four values but after I tried it again it worked fine, sorry for that.

We don’t run on battery and want to monitor machines with several hundred watts, so power efficiency is not a primary goal. But thank you for this hint. Are there any other advantages on the RC oscillator in comparison to the synthetization (faster boot up, …)?

[Vidar Berg]

No worries, thanks for the update. So it doesn't sounds like the SYNTH clock is going to have any actual impact on the current consumtion in your case then. The only advantage I can think is that the RC oscillator requires less power. The SYNTH clock should not have any negative impact on boot time.