Issues with flashing code on MDBT53V mounted on cusotm board

RE: Issues with flashing code on MDBT53V mounted on cusotm board

Marosh — Wed, 13 May 2026 06:57:42 GMT

Actually this worked. I have used the nRF52840DK, JTAG connector to connect P19 to my custom board and add the 1.8V to the nrfDK on SWDsel of P20. (SB19 shorted, SB47 not)

RE: Issues with flashing code on MDBT53V mounted on cusotm board

Marosh — Wed, 06 May 2026 05:35:51 GMT

The nRF52840DK version is 3.0.3 or I have also nRF5340 at hand of version 2.0.2.

Unfortunately due to space constraints on my custom pcb not much is exposed meaning that i would need to solder wires for each programming for multiple boards to skipping the jtag cable is kinda no go for me.

Could you you elaborate more on the VTG please? So for my current setup it is correct to short the jumper SB19 and also I should connect the onboard 1.8V voltage on my custom pcb to the VTG pin on P20?

With regards,
John

RE: Issues with flashing code on MDBT53V mounted on cusotm board

JONATHAN LL — Tue, 05 May 2026 22:20:40 GMT

What version of the nRF52840DK do you have? If it is an older version the debugger on the DK is not able to program the nRF5340 on the MDBT53V module.

Here is an example on how to connect a external device for programming not unsing the 10pin connector.

if you are running things of different voltages this might be the issue. Its ok to use the VTG to detect voltage from P20, so you can use P19 together with a jumper for VTG.

Also we can help with schematic and layout reviews if you want to have your design checked.

Also you can try and run a "nrfutil device info" command or "nrfutil device recover" if the approtection is on in the terminal instead of having to run the flash script every time.

Regards,
Jonathan