nrf52840dk Jlink OB USB cdc offsets 1 character

RE: nrf52840dk Jlink OB USB cdc offsets 1 character

user91187 — Tue, 22 Feb 2022 11:59:53 GMT

Sorry for the misunderstanding,

Yes the interface MCU has a bootloader on it, you can access it by holding the reset button while powering on the kit, does show up as a BOOTLOADER drive.

then its drag and drop.

Regards,
Jonathan

RE: nrf52840dk Jlink OB USB cdc offsets 1 character

user94364 — Mon, 21 Feb 2022 23:05:43 GMT

Hi Jon,

In this case I was referring to programming the Atmel (Microchip) based ATSAM3U2CA - the IC chosen to use as the Jlink OB. I do believe this IC is supported by the Atmel ICE. However, I do also have an external JLink Pro that I could use to reprogram the Onboard Jlink OB as well. Though I don't know what the best way to go about it. Does the OB for instance, have a bootloader that I could simply upgrade/reflash its firmware over USB? Or is it better to reflash the chip entirely?

As you mentioned though if I don't come to a solution, I may just bypass the USB CDC convenience and use and external USB to Serial converter.

Cheers,

Ryan.

RE: nrf52840dk Jlink OB USB cdc offsets 1 character

user91187 — Mon, 21 Feb 2022 13:29:17 GMT

Hi,

The Atmel ICE programmer will not work, as far as i am aware it does not support nRF products, so you will have to find some other tool to use it i belive.

It has ben asked before here: (+) nrfjprog supported SWD devices - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

Can you try to use a different interface, bypass the debugger chip. Cutting SB50 to 53 will give you access to the MCU lines so you could use something else then the onboard programmer chip.

Regards,
Jonathan

RE: nrf52840dk Jlink OB USB cdc offsets 1 character

user94364 — Mon, 21 Feb 2022 00:29:07 GMT

Unfortunately, I only have the 1x nrf52840dk. It is also the only Nordic kit I have that contains the onboard J-Link IC. All others require the external programmers.

Edit: Also note I have Atmel Studio installed with an Atmel ICE programmer, so if required I could simply write any new/old binary with that. If, of course the security IO is not set etc. I know this is a competitors IC of sorts, so it could be a bit of a conflict and I am happy to reach out to Segger directly if that's more appropriate.

RE: nrf52840dk Jlink OB USB cdc offsets 1 character

user91187 — Fri, 18 Feb 2022 15:42:44 GMT

Hi,

Do you have a different DK to test and probe to see if it acts differently? just to confirm that it might be a JLink OB IC issue.

I will look at this case and get back to you with more questions and answers, early next week.

Regards,
Jonathan