Can't set CONFIG_BOARD_ENABLE_DCDC=n on custom board

[alex101]

Hi there,

I have a small custom board with the nRF52810 that uses the LDO instead of the DC-DC, it also doesn't have the 32KHz LF crystal.

Was able to add this to the defconfig file / prj.conf which compiles fine:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

But in trying to add CONFIG_BOARD_ENABLE_DCDC=n and re-compiling results in an error:
warning: attempt to assign the value 'n' to the undefined symbol BOARD_ENABLE_DCDC

Does anyone know how to solve this? The other threads I've seen show it works for others but that was a year ago or more.

Thank you!

[Kazi Afroza Sultana]

Hello,

What do you see if you run this command nrfjprog --memrd 0x40000578 --n 4?

[alex101]

Hi, this is the result:
0x40000578: 00000000

I'm new to this environment, using nRF Connect SDK v2.8.0 on Visual Studio Code.

While I have you, is there a delay_ms function available? I think the small nRF52810 custom board I'm using kind of is working but something isn't quite right so it would be good to validate if the clock is set correctly. (Wireless packet received takes 8s to process and turn on an LED when not debugging but when debugging and holding down F10 it updates quicker. If pressing F5 a few times, it stalls. On the DK itself, it works perfectly). Might need to open another support request if needed.

(Edit: I reflashed the DK board and the 8s lag was also present on it, reverted back to the old files I have and the DK board works so now I need to figure out what happened - code didn't change at all).
It seems like adding "CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y" causes the slow down but I think that line is needed if you don't have the 32.KHz crystal populated?

[alex101]

I think it's solved. went back to selecting the board configuration as the 52810 DK, edited the prj.conf file with this:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_SYNTH=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=n

Found from here:
after setting CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC the 32mhz start working from rc instead from XTAL

And then in nrf52dk_nrf52810.dts changed the regulator setting:
&reg {
    //regulator-initial-mode = <NRF5X_REG_MODE_DCDC>;
    regulator-initial-mode = <NRF5X_REG_MODE_LDO>;
};

Probably best to make a copy of the board config and make my own board config based on it.

Strangely I do always have to unplug the USB and reconnect for the custom PCB to reset properly.