nRF54L15 blinky will not return from k_msleep()

[Ryan S]

Hi, 

I am currently developing on the BL54L15 Ezurio development kit with the Nordic chip. 

I am using the Nordic v3.0.1 SDK and toolchain with the new manufacturer board files from the zephyr repository https://github.com/zephyrproject-rtos/zephyr/tree/main/boards/ezurio/bl54l15_dvk

I have tried both the blinky and button sample - but code execution seems to stop when reaching the k_msleep() function. I have not had this issue with the nRF54L15 development kit using the same SDK and toolchain.

When I try to enter debug mode (following the usual way outlined in the dev academy course) - I get the following message: 

'Unable to start debugging. GDP exited unexpectedly with exit code -3 (0xFFFFFFFD). Could not connect to target. No target voltage detected or connection failed.'

I understand that nordic is not responsible for manufacturing this board - however I was wondering if you could suggest any starting points for debugging the fault in k_msleep in case there is an error in the board files or hardware. 

Thank you very much. 

[Kazi Afroza Sultana]

Hello,

The accuracy and behavior of k_msleep() are directly influenced by the LFCLK configuration and source (e.g., RC oscillator, crystal oscillator, or synthesized clock. The default LFCLK source is the LFRC. If your board does not have an external 32.768 kHz crystal, you should explicitly set the LFCLK source to the internal RC oscillator. You can set these in the prj.conf file

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC_CALIBRATION=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_500PPM=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=n
CONFIG_CLOCK_CONTROL_NRF_K32SRC_SYNTH=n

Regarding this '''Unable to start debugging. GDP exited unexpectedly with exit code -3 (0xFFFFFFFD). Could not connect to target. No target voltage detected or connection failed.'' error, it may indicate the custom board is not properly powered.

You can check the power supply if it is properly powered, check the debug connections and cables. Trying with external debugger could be an alternative choice if onboard debugger does not work. In addition to there, try power cycling the board and erase the board completely before flashing.