Recover nrf5340 (MDBT53) custom board

RE: Recover nrf5340 (MDBT53) custom board

JONATHAN LL — Wed, 21 May 2025 13:45:37 GMT

Hi, sorry for the slow response.

[quote user="Hassam Arshad"]Anyway any idea how. we can recover this or make this work again?[/quote]

To recover a board that has the been flashed with the wrong firmware you would need to supply the external pins related to DCC with power or at least get it in a state before it shuts down due to the wrong regulators being enabled. In many cases the device is bricked as the pins are not always accessible. If that is the case then it needs to be removed and either replaced or mounted to a board where all pins are available and re-programed\recovered.

Since you have a module you should be able to access the pins connected to the different regulators so this could possibly be solved.

In the code when you compile it you should be able to see if the registers for the regulators are on or off before you flash it to the device. There should be a Zephyr.dts file that is generated, maybe for the bootloader.
It might be that the bootloader overwrites the configs if not done correctly.

Regards,
Jonathan

RE: Recover nrf5340 (MDBT53) custom board

Muhammad — Thu, 08 May 2025 21:37:30 GMT

can you give any update on it?

RE: Recover nrf5340 (MDBT53) custom board

Muhammad — Sun, 04 May 2025 22:05:52 GMT

Hi,

Thanks for quick response. I am not sure about the circuit but I know from my colleagues that we have explicitly disabled it in the code. like this

# disable DCDC
CONFIG_BOARD_ENABLE_DCDC_APP=n
CONFIG_BOARD_ENABLE_DCDC_NET=n
CONFIG_BOARD_ENABLE_DCDC_HV=n

I haven't done anything with code but added bootlaoder code into the current version of code and then this happened. So one thing I dont understand is why the device goes to this state as I have never seen something like this before as I did work on mcu boot serval times.

Anyway any idea how. we can recover this or make this work again?

Regards,

RE: Recover nrf5340 (MDBT53) custom board

JONATHAN LL — Sun, 04 May 2025 21:48:11 GMT

Hi,

Foes you custom board use DCDC or LDO mode of operation?

If you do not have the DCDC external components in place you will "brick" the device.

Form the Raytac docs, see the recommended circuit for the DCDC mode.

Regards,

Jonathan