Programming external target using nRF54L15 DK

RE: Programming external target using nRF54L15 DK

PaKa — Mon, 13 Oct 2025 08:30:46 GMT

And you have connected all the necessary signals (6 in total) and is powering the external board with the same voltage as the DK is set to? And the cable is less than 10cm long?

Can you send a picture of the setup?

RE: Programming external target using nRF54L15 DK

Nasib — Fri, 10 Oct 2025 17:18:51 GMT

exactly same problem here... regardless the cable length i am unable to see any kind of signal with my oscilloscope in the swclk or swio lines... and just when i short the SEL to GND is when i get the same error

RE: Programming external target using nRF54L15 DK

Sai — Fri, 25 Apr 2025 01:57:32 GMT

I ordered a 50mm cable from Mouser and tested it. I am now able to program the board.

RE: Programming external target using nRF54L15 DK

Sai — Wed, 23 Apr 2025 15:07:30 GMT

Yes. The VDDM jumper is always on as the board won't work without it. Let me try to source a shorter cable.

RE: Programming external target using nRF54L15 DK

PaKa — Wed, 23 Apr 2025 11:03:39 GMT

You should look for a 50mil/1.27mm pitch cable shorter than 5-6cm. Digikey at least have some so don' believe they should be too difficult to find. Simon's link is for a 100mil/2.54mm pitch cable so won't work

RE: Programming external target using nRF54L15 DK

Simonr — Wed, 23 Apr 2025 09:23:31 GMT

I googled around and found this one really short one at least: https://thepihut.com/products/10-pin-socket-socket-idc-cable-short-1-5 . As Paal suggests, request this from the distributor of your choice. Most distributors should have shorter ones available. Sorry for linking to the wrong format.

A 3.3V power supply should be fine.

Regarding the jumper, you will need the jumper on the VDDM current measurement jumper P6 as it is placed by default.

Best regards,

Simon

RE: Programming external target using nRF54L15 DK

Sai — Tue, 22 Apr 2025 14:53:37 GMT

Can you recommend a source for shorter cables? The shortest I could find was 150mm.

RE: Programming external target using nRF54L15 DK

Sai — Tue, 22 Apr 2025 07:35:24 GMT

Just to be clear:

I need to use a shorter cable.
The VDD for the external target and the DK need to be the same. I am powering the external target using a 3.3V power supply. Is this enough?
Which jumper are you referring to? The instructions in the documentation didn't specifically mention any jumper unless I missed it.

RE: Programming external target using nRF54L15 DK

Simonr — Tue, 22 Apr 2025 07:28:54 GMT

Okay, so the SWD cable length supported for flashing external boards is shorter than for previous DKs. This will make it into the DK user guide in the future. If you have an SWD cable shorter than 10cm I suggest giving that a try. The shorter the better really. Also note that the DKs VDD and the external VDD needs to be the same, and the target power jumper must be mounted.

Best regards,

Simon

RE: Programming external target using nRF54L15 DK

Sai — Tue, 22 Apr 2025 07:01:20 GMT

Attached is my image of my programming setup. As I mentioned before, the same cable works on an nRF52840-DK board.

RE: Programming external target using nRF54L15 DK

PaKa — Tue, 22 Apr 2025 06:56:01 GMT

What is the length of your programming cable?

RE: Programming external target using nRF54L15 DK

Simonr — Tue, 22 Apr 2025 06:48:42 GMT

That sounds very strange, can you show me an image of how you connect the board to the nRF54L15 DK on your end so I can double check it's all correctly connected. Based on your description it seems good.

Best regards,

Simon

RE: Programming external target using nRF54L15 DK

Sai — Thu, 17 Apr 2025 15:51:55 GMT

I have a workaround for my problem. I am able to program the board via the nRF52840 DK. I also upgraded the JLink firmware on my nRF54L15 to see if that would fix it.

While I have a solution, I wish I could program it using nRF54L15 DK.

RE: Programming external target using nRF54L15 DK

Sai — Wed, 16 Apr 2025 14:28:13 GMT

Yes. The target is powered with a 3.25V supply. My board is at 3.3V levels. I am using an NPM1300
I have connected my target to the debug out port (P19).
My nRF54L15 DK version is 0.9.2 and the sticker says PCA10156.

I am happy to share the schematic and picture of my board.

I am able to detect the external target using the nRF52840 DK. It is just the nRF54L15 DK that doesn't connect to the target.

RE: Programming external target using nRF54L15 DK

Simonr — Wed, 16 Apr 2025 11:54:39 GMT

Can you confirm the target board is powered with a voltage between 1.8 and 3.6V, and that VDDIO on the custom board also is within this range? Also confirm that you have connected the board to the correct debug header on the DK. If it still doesn't work I think we need to do a HW review to confirm the module schematic and layout looks correct.

Also, what version of the nRF54L15 DK do you have. What does it say on the sticker that starts with PCA10156?

Best regards,

Simon