Flashing nRF 5340 Custom Board with nrf52dk v1.2.4

[Nitro0]

Hello!

I am having troubles with my custom board using BL5340 from Ezurio. I have tried to flash it via my nrf5340 Audio DK but realized it doesnt support external Flashing. Then i got my Hands on a nRF52dk v1.2.4 which has the option to use the J-Link as external Programmer, however it cannot get it to flash my BL5340. In my Understanding when VTref senses my 1.8V Supply voltage it should be able to output accordingly. But i always get the error: Could not connect to the target device.

Here is how i Connected everything:

nrf52dk	BLE5340
EXT VTG	1.8V
SWDIO	SWDIO
SWDCLK	SWDCLK
RESET	RESET
GND DETECT	GND

Flashing Attempt Log:
Connecting to target via SWD
ConfigTargetSettings() start
ConfigTargetSettings() end - Took 6us
InitTarget() start
InitTarget() end - Took 219ms
Connect fallback: Reset via Reset pin & Connect.
ConfigTargetSettings() start
ConfigTargetSettings() end - Took 5us
InitTarget() start
InitTarget() end - Took 220ms
Error occurred: Could not connect to the target device.


I have also seen other Tickets stating the nrf52dk cannot flash its successors, and other Tickets saying its no Problem. 
There also might be an Issue with my PCB but every Net seems fine and it currently doesnt even have any peripherals connected.

Additionally i tested it by using a 3.3V Domain on my PCB and had the same error.

One more Question: If i buy a Segger Link Edu Mini can this debugger just flash my PCBs directly using 1.8V or are there other Problems.

Thanks for your Help!

[Einar Thorsrud]

Hi,

The onboard debugger on the older nRF52 DKs cannot program nRF5340, regardless of voltage. (A nRF52 DK version 3.0 or higher should be able to though, but you still have the problem with votlage. An alternative here could be to use an RF54L15 DK, which also has configurable voltage. But note that the DKs are not ment for production programming).

Regarding J-Link EDU Mini that should support support it, and also with regards to the voltage. But there are license limitations when it comes to using that commercially, so if that is the case, you should consider another. I recommend contacting Segger about this.