Programming XIAO nRF52840 using nRF Connect and devkit J-link

I’m attempting to program my board using the nRF Connect SDK, with the nRF52840 development kit as a more affordable J-link. I’ve wired it up like so (Image borrowed from this post):

After connecting everything up, it looks like it should be working; I see in the terminal that the flash is programmed and verified, and it becomes unrecognized by Arduino afterwards so something happens, but it doesn’t appear to do what it should, even a basic blinking example. Have I connected everything correctly? I connected VDDnRF to 3v3 on the expansion board.

Are you able to read the device with the Programmer in NRF Connect for desktop?
should look like this. Or

GL :slight_smile:

I’m using it this way with the PPK2 in line with the battery and Debug in Platform IO while watching the power consumption…

When you press debug in Platform io it will pop up a Jlink box and push the code to it.


I am unsure what to make of this. The development kit I am using for its J-Link is running the Blinky example, and I’m assuming what I’m seeing is the kit rather than the board attached to it.

Also asked on the nRF dev site: External nRF52840 board appears to flash but won't do anything - Nordic Q&A - Nordic DevZone - Nordic DevZone

So what does it do if you do a READ button?
GL :wink: NO soft device detected… id0x123 (S140 v7.3.0)It’s a Blank?

That was after pressing the read button; I pulled up the build file to confirm (zephyr.hex) and this is all it shows

This is what I see if I do a read on the dev kit, which is running a working blinky example (and its corresponding zephyr.hex on the left):

Figured it out with help from a Nordic dev; the board files were made for the old SDK and expect/leave room for a no-longer-needed SoftDevice. In xiao_ble_defconfig in the board files, I had to set CONFIG_BUILD_OUTPUT_UF2=n and CONFIG_USE_DT_CODE_PARTITION=n

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Great, so why is the SD no longer needed?
Good work , those guys are very helpful on the Nordic site.
GL :slight_smile:

I guess it’s integrated into how the new SDK works?

I haven’t had any chance to wrap my head around the SES stuff and pretty much hit the basics and get it done with VScode’s, PlatformIo and the debugging works perfectly. Arduino IDE 2.0 on the other hand, works ok but it’s like a toy with NO debugging and it’s annoying file open and Board and chip selection wacky code. It’s terrible such a great hardware and footprint design is SOooo hampered by the firmware and lack of any engineering Software support. (you only need look to the reply’s column’s in the Forums category index)
GL :slight_smile:

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