Bluetooth Low Energy V3.0.0 - Programming nRF52-DK in macOS (J-Link 64 byte limit MSD Disable Issue)

[alwalker]

In order to use this application in nRF Connect for Desktop, I have just purchased an nRF52-DK. As I'm using macOS, I believe that I'm affected by the 64 byte limit and need to disable the MSD function. The instructions that Nordic links to says to use J-Link Commander, but I do not have this application as part of the Segger installation.

https://wiki.segger.com/J-Link_OB

Could you advise how to disable the MSD function please?

Nordic Semi documentation:

Important: When using OS X, an issue with the SEGGER J-Link OB firmware leads to the corruption of long packets over UART. See www.nordicsemi.com/nRFConnectOSXfix for more information.

Log file attached for reference.

Kind regards,

Al

[Vidar Berg]

Hi,

Please try to run "JLinkExe" from the terminal. This is the name of the Jlink commander executable on macOS and Linux.

Best regards,

Vidar

[alwalker]

Thanks Vidar, I've done that:

In macOS Terminal, navigate to folder with JLinkExe:

alwalker@Als-MBP-2 JLink_V758b % JLinkExe

Then type:

J-Link>MSDDisable

Probe configured successfully.

J-Link>

However this doesn't appear to fix the issue, log file attached.

2022-02-25T14_00_30.249Z-log copy.txt

[Vidar Berg]

Did you remember to power-cycle the board after running the MSDDisable command. This is necessary for the change to take effect.

[alwalker]

Yes I did thanks, no difference

[Vidar Berg]

From the log it seems like this is an issue with the debug readback protection being enabled, not with the VCOM interface.

You can run the following command from the debug terminal to unlock the chip:

$ nrfjprog --recover

What version of the DK do you have? You can find the version number printed on the white sticker on top of the interface chip.