How to use nrf52840DK and vscode extention to flash external board?

RE: How to use nrf52840DK and vscode extention to flash external board?

X4ce — Thu, 30 Jan 2025 14:20:14 GMT

It is good to hear that you are able to connect with your custom board. However, it is strange to know that SWD_SEL should be set to HIGH in order to connect with ext. SoC. Whereas, it worked for you when set to GND.

RE: How to use nrf52840DK and vscode extention to flash external board?

xutengl — Thu, 30 Jan 2025 13:49:07 GMT

Hey Simon,

Thanks for your help earlier. I resolved the issue with the following adjustments:

Set SW6 to Default (ON)
Connected SWD0_SEL to GND
Selected nRF52832DK (my target board) as the build target

Settings I kept the same:

SB19 remains connected
Maintained SWDIO, SWCLK, RESET, and GND connections between the DK and the external board

To confirm that the interfacing IC on the DK is indeed connected to the external board, I flashed a HelloWorld logging firmware onto the onboard MCU. When powering on the DK alone, I observed my custom message periodically printed to the console. However, when I connected the SWD cable and re-powered the DK, the logging stopped—confirming the interfacing IC is connected to the external board.

Thanks again for your assistance!

RE: How to use nrf52840DK and vscode extention to flash external board?

Simonr — Wed, 15 Jan 2025 11:52:05 GMT

It will be the MCU debugger's serial number you see under "Connected Devices", not the external nRF's serial number no matter which nRF device it's connected to. The SW6 is only to cut off power to anything but the nRF52840 SoC on the DK, so the onboard debugger won't get power if SW6 is set to nRF ONLY. If an external board is connected, the debugger will detect it and automatically program the external board instead of the onboard one, so SW6 should not be necessary to use for your purposes.

Both connectors P19 and P20 should work just fine.

Best regards,

Simon

RE: How to use nrf52840DK and vscode extention to flash external board?

xutengl — Wed, 15 Jan 2025 05:23:52 GMT

Thanks, I’ll try connector P20 as you mentioned next. It would be odd if P20(SWD1) works but P19(SWD0) doesn’t.

RE: How to use nrf52840DK and vscode extention to flash external board?

X4ce — Wed, 15 Jan 2025 03:42:30 GMT

Hi,

This is a reference schematic for flashing external board.

Regards