nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

PaKa — Tue, 31 Mar 2026 06:36:23 GMT

The GPIO feature must be built into the program. I don't know if the sniffer SW includes it but to test you program the sniffer code and then try to use the Dongle with the nRF Connect for Desktop programmer or RSSI apps. If it has the DFU trigger library then you can program the board without using the reset button. If you need to use the reset button then it doesn't.

For code you build yourself then you will need to add the feature to the code.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

chuck rekiere — Mon, 30 Mar 2026 17:30:32 GMT

If the sniffer is programmed on the nRF52840 is there a way to access the GPIO? Or would the reset need to be pushed to enter the programming mode? I see a path forward for the advertisement updates, yet not a method of programming the sniffer then moving towards the advertizement code and back?

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

PaKa — Fri, 27 Mar 2026 08:49:29 GMT

Based on the device support it looks like not it.

Basically the nRF5 SDK solution adds a USB end point (so will only work with USB capable devices) and accessing this will trigger a reboot which will stay in DFU mode. This is done by pulling the GPIO pin on the nRF52840 connected to the RESET pin low.

If you embedd code in your project that pulls this pin low then you will always go to DFU mode so you can achieve this in whatever way you want.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

chuck rekiere — Thu, 26 Mar 2026 16:43:18 GMT

Thank-you , The nRF52840 DFU Trigger would solve many of our issues if it will allow for re-flashing the dongle.

I grepped the sdk-nrf code and see /tests/subsys/dfu/...and /samples/dfu/duf_target ... is this along the right track?

also found this

https://docs.contiki-ng.org/en/develop/_api/usb-dfu-trigger_8c.html#details

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

PaKa — Wed, 25 Mar 2026 12:07:05 GMT

Remember that someone doing something doesn't mean it is legally allowed....

The nRF5840 DONGLE can be updated without using the button. There is a specific USB service in the nRF5 SDK named something along "DFU Trigger". This sets up an additional USB endpoint that if accessed in the correct way will trigger the DFU action. This is used by nRF Connect or Desktop to trigger DFU when you use Nordic code in the Dongle. You can add this to your own code if you want to. Not sure if this code is present in nRF Connect SDK but you can check if this seems like a solution for you.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

chuck rekiere — Tue, 24 Mar 2026 20:26:29 GMT

Nod, we are looking into options. We could have a dongle be a dedicated sniffer.

We were looking into seeing if the DK board could be a sniffer or be re-flashed to do advertisements.

Also, we have some software running on the DK board what we would like to have field up-gradable (thus reflash) , basically bug fixes and feature updates.

With the dongle from my understanding you need to hit the reset button to force an upgrade (I have not done the dongle update, only have done updates with the DK boards). Unless there is a way to update.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

PjGlasso — Mon, 23 Mar 2026 20:39:21 GMT

Hi there,

So, WHy would you want to use the DK that way? What's the END goal here?
I recall a while back , Someone was shipping the Sniffer setup on the Dongle as part of their end product.

I don't recall reading anything about Licensing needed if doing it that way. I'm pretty sure they made up a UF2 file to drag and drop onto the dongle prior to shipping it. Which makes it a dedicated device?

HTH

GL :-) PJ :v:

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

chuck rekiere — Mon, 23 Mar 2026 15:33:06 GMT

The product that contained 5 nRF54L15 boards and 5 nRF52840 dongles (as sniffers) would need FCC certification. Would the same product need to have bluetooth certification ?

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

PaKa — Mon, 23 Mar 2026 14:57:14 GMT

None of the kits are FCC certified as they are all development kits so if you are to ship them in an end product then you will need to FCC certify the completed product you plan to make.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

chuck rekiere — Mon, 23 Mar 2026 14:54:33 GMT

Thank-you, you answers are helping us find a path forward.

1. "Buy the DKs /programmers" - This rout would be to purchase a NRF52480 - DK or NRF54L15 - DK and place in the piece of test equipment and reference that the product contains the Nordic boards ?

2. The nRF52840-DK has a note on the screening "For evaluation only : not FCC approved for resale". This any clone off the reference design would need to get FCC approval ?

3. As you mentioned previously to work around the nRF54L15 - DK not having the sniffer is to use it in combination with the The nRF52840 Dongles.
devzone.nordicsemi.com/.../549902

4. The nRF54L15 - DK does that have FCC approval?

5. The nRF52840 Dongles do have FCC approval?

6. Would a product with a combination of nRF54L15 - DK and nRGF52840 Dongles need blue tooth certification or would it fall under the nordic board certification ? The product would just have tho have some reference to "Product contains Nordic nRF54L15 - DK and nRF52840" ?

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

PaKa — Mon, 23 Mar 2026 08:44:02 GMT

The HW design for the Nordic DK has a permissive license and you are allowed to copy the design without anything more than attribution.

The FW used on the DKs are under SEGGER license and what you need to negotiate with SEGGER.

You can find the Nordic licenses used in the blog section here on Devzone, search for blogs.

To make a short answer: trying to go down the SEGGER path is very unlikely to succeed. Recommend to either buy the DKs/programmers or go the open source route.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

chuck rekiere — Fri, 20 Mar 2026 15:45:15 GMT

There looks to be issues with our approach (please correct me if I am wrong)

1. Need to buy the SW and license from SEGGER

2. Need to have ability to licence and flash Nordic fw so as to be able to load the SEGGER SW

3. Need to license the hardware design from Nordic

4. Need to license the Nordic Firmware (which Nordic does not provide the firmware).

Also is there a link to the Nordic DKs licensing agreements?

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

PaKa — Fri, 20 Mar 2026 07:48:13 GMT

The SEGGER OBD code is not available for external use. If you want access to this then you will need to buy the SW and license from SEGGER.

All the Nordic DKs are sold as development kits and also certified as this.Development kits have different rules than end products so if you plan to include it in an end product then you will need to certify it yourself.

All of the restrictions on use of the Nordic DKs are in licensing agreements.

Second option for you is as Turbo J said, use an open source alternative instead. No guarantees that this will work with Nordic SW tools as these are built around SEGGER JLINK support.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

chuck rekiere — Thu, 19 Mar 2026 22:16:20 GMT

Looks like the initial answer is possibly not from Nordic. Will await an offical Nordic response.

Hi,

Thank-you for the quick response. (that is much appreciated!)

Question 1.
if we use a board like the nRF54L15 and purchased from nordic could we include it in a product as is. Or is there another additional license. The limitation on the nRF54L15 board is that it didn't have the sniffer integration with wireshark?

Question 2.

https://www.nordicsemi.com/Products/Development-hardware/nRF52840-DK/Download#infotabs

I did not see the licensing information for the board design. Please provide that information on licensing, in the past the reference designs were present to use as a reference we made one sight modification on the J1 connector as the one on the nRF52849 didn't work with our antennas. Please provide a link the the licensing the intent was not to violate any licensing.

Appreciate the information on the MCU , so Hardware 3.0.3 has NRF5340 .

If we went the VSLink route, could you give some insight on how the flash the board.

RE: nRF52840 DK board developed off Hardware files v3.0.3 would like to get the on-board SEGGER J-Link debugger flashed on the board

Turbo J — Thu, 19 Mar 2026 08:41:53 GMT

You made a counterfeit board, tried putting firmware for the wrong MCU (Hardware 3.0.3 has NRF5340 and not an ST SAM3U) on it and expected it to just work? WTF?

Newsflash: There is SEGGER licensing stuff on the commercially sold boards that is not public. You will need to contac both Nordic and SEGGER for licensing.

Best you could do with publicly available information would be writing your own firmware (I've used VSLink in the past) for OpenOCD. This way you can't use any Nordic or JLink Software though.