RE: How to get log of nRF52840 board from 52DK

helsing — Mon, 24 Nov 2025 13:45:44 GMT

Hi,

Is the custom board designed with an external inductor in order to use the DCDC? Try disabling the DCDC:

1. Disable DCDC in your configuration if your hardware does not support it. Add this to your prj.conf:

CONFIG_BOARD_ENABLE_DCDC=n
CONFIG_BOARD_ENABLE_DCDC_HV=n

If it still does not work:

2. Set the LF clock source to internal RC if you do not have an external 32kHz crystal. Add this as well:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=n

Please let us know if you are still having problems.

Has your custom board been reviewed by anyone at Nordic? You may upload the design if you would like us to take a look at it. Either make this ticket private (unless you would like to share the design), or make a new private ticket and upload a PDF with the schematic.

RE: How to get log of nRF52840 board from 52DK

always18 — Sun, 23 Nov 2025 14:07:22 GMT

I add a 10k pull-up resistor to 3.3v at p0.18，and connect a 3V battery to the 52840 board , but the software still doesn't run,

from the puls of p0.18,i can see a low puls about 65ms。what's wrong?