Flashing failed due to protection on the device

[Bryan]

OS: Windows 10
NCS: 2.0.0

I am working on the Nordic DFU NCS Guide on a nRF52833 DK  devzone.nordicsemi.com/.../ncs-dfu

After flashing/debugging several times, I started seeing the message below.  I responded with "yes".   Now I am not able to "debug".  I can only "flash" it. 

I thought something was wrong with the board, so I used a brand new nRF52833DK.  The same thing started happening.  

Any idea of what is going on?

[dejans]

Hi,

I have reproduced your issue by erasing the board and power cycling it, but as soon as the board was recovered the issue disappeared.
After you recover the board with

nrfjprog --recover

or from VS Code, APPRPOTECT should be disabled. Normally, it should stay in disabled state unless your application enables it. You can check which APPROTECT options you have enabled in your application by looking at .config file in your build\zephyr folder. You can find more information about APPROTECT in the documentation. 


Best regards,
Dejan

[Bryan]

dejans,

Thank you for the response.  Yes, I had already tried "nrfjprog --recover".  That did not resolve the issue.

I went through your recommendations, the only APPRPOTECT in build\Zephyr\.config are:

CONFIG_NRF_APPROTECT_USE_UICR=y
# CONFIG_NRF_APPROTECT_LOCK is not set

I added the below to prj.conf, but .config stayed the same.

CONFIG_NRF_APPROTECT_USE_UICR=n

Even if I run "nrfjprog --recover" and try to program a completely different application (BLE app), I get the same error.  You can see in the terminal the --recover option is run when I "flash", followed by a power cycle, and then try to "debug".

[Bryan]

One other piece of information.  If I switch to any other project, I am still getting the same warning and I am unable to "debug", but can "flash".

[dejans]

Hi,

You could try recovering in a separate nrfjprog command, before flashing.

Best regards,
Dejan

[Bryan]

I did that, too.  
1. nrfjprog --recover
2.  Try to "debug".  It downloads without error, but when I click "go", it does nothing.

This is just bizarre.  There is obviously some low level or tool issue.  I can't waste time trying to figure it out.  I will have to live with flashing and no debug.

[dejans]

Hi,

In order to avoid black window in your initial screenshot from showing up again, you can either choose "Yes" or "Always in this session" which should enable flashing with recovering. Then, this black window should disappear. Another option would be to create custom flash task where you could specify how you want flashing to be performed. Having said that, readback protection might be re-enabled if you build and flash application which enables it.

Best regards,
Dejan