Problem to upload to nRF52-DK

[PedroMF]

Hello,

I just got in these days a nRF52-DK and just today I started to try stuff with it, I want to use PlatformIO and Zephyr.

First I try this:https://docs.platformio.org/en/latest/tutorials/nordicnrf52/zephyr_debugging_unit_testing_inspect.html#tutorial-nordicnrf52-zephyr-debugging-unit-testing-analysis then I realized that I needed to install USB drivers https://docs.platformio.org/en/latest/plus/debug-tools/jlink.html#debugging-tool-jlink, it looked like upload, because the led were blinking, but after power off and on was no possible to upload again.

I start to look for solutions but it is no possible to do "nrfjprog --recover" throws an error "[error]: [  nRF52] - Access protection is enabled, can't read device version." ad the target and "nrfjprog --deviceversion" throws "NRF51xxx_xxAA_REV1" instead of "NRF52832_XXAA" the other strange stuff is the "VTref=3.300V" in the target info in PlatformIO when trying to upload.

Also it is no posible to put the nRF52-DK in bootloader mode as described in https://infocenter.nordicsemi.com/index.jsp?topic=%2Fug_nrf52832_dk%2FUG%2Fnrf52_DK%2Fboot_reset_but.html, but the jlink interface is recognized in JLinkConfig.exe but I could find a link to download a firmware for JLink_OB_nRF5340_NordicSemi the one on the site of nRF52-DK is J-Link-OB-SAM3U128-V2, and maybe use JLinkConfig to upgrade the firmware. I am not sure if the problem is the nRF5340 Interface MCU or the nRF52832 that remains in a strange stage.

Any way I will tray more stuff but I hope help in this issue because the DK was just new,

best regards,

[PedroMF]

No nothing special https://docs.platformio.org/en/latest/tutorials/nordicnrf52/zephyr_debugging_unit_testing_inspect.html#tutorial-nordicnrf52-zephyr-debugging-unit-testing-analysis 

[Hung Bui]

Hi Pedro, 

Could you send us the hex file that generated from the example ? Especially if you still have the hex that you used to flash on the board ? 

We are suspecting that the example may trigger manual system reset too early or enable WDT that can trigger a reset too early. 

Here is a quote from our R&D team: 

It seems that the recover hardware mechanism does not work as intended.

nrfjprog writes the device CTRL-AP.ERASEALL register, but the CTRL-AP.ERASEALLSTATUS flag never indicates that the operation has been completed.