board nrf52832 does not connect anymore

[jean-marc]

I am following the BLE accademy course and flashing an exercise, the exercise did not perform as requested.

I could not flash anymore.

I clear the board from the switch button and then could not connect the board anymore even I coud see it by the JLINK or nrfConnect or Teraterm.

I tried several version of JLINK without success.

I then made a power ON with the IfBoot pressed and the board now act strangely.

The board led flash every second for a while and is visible on the USB but then flash rapidly and disapear from the USB.

Reading manuals I do not understand what to upload here, what file, how...

Some manual indicate the use of nrfGo which is obsolete... I am completly lost.

Thank you for some hints to start again.

JLINK 780c

nRF Connect 4.2.0

[Håkon Alseth]

Hi,

 

Given that one of the LEDs are turned on, it might indicate that there's firmware running on your device.

You can try two other options:

* Use J-Link Commander to recover the device

* Use a batch script that runs "nrfjprog --recover -f nrf52" in a loop

 

Here's a way to use J-Link Commander (search in the start meny for it):

device NRF52
si 1
speed 1000
connect

 

Here's an example of how it should look when it has been successfully found

Type "connect" to establish a target connection, '?' for help
J-Link>device nrf52
J-Link>si 1
Selecting SWD as current target interface.
J-Link>speed 1000
Selecting 1000 kHz as target interface speed
J-Link>connect
Device "NRF52" selected.


Connecting to target via SWD
InitTarget() start
InitTarget() end
Found SW-DP with ID 0x2BA01477
DPIDR: 0x2BA01477
CoreSight SoC-400 or earlier
Scanning AP map to find all available APs
AP[2]: Stopped AP scan as end of AP map has been reached
AP[0]: AHB-AP (IDR: 0x24770011)
AP[1]: JTAG-AP (IDR: 0x02880000)
Iterating through AP map to find AHB-AP to use
AP[0]: Core found
AP[0]: AHB-AP ROM base: 0xE00FF000
CPUID register: 0x410FC241. Implementer code: 0x41 (ARM)
Found Cortex-M4 r0p1, Little endian.
FPUnit: 6 code (BP) slots and 2 literal slots
CoreSight components:
ROMTbl[0] @ E00FF000
[0][0]: E000E000 CID B105E00D PID 000BB00C SCS-M7
[0][1]: E0001000 CID B105E00D PID 003BB002 DWT
[0][2]: E0002000 CID B105E00D PID 002BB003 FPB
[0][3]: E0000000 CID B105E00D PID 003BB001 ITM
[0][4]: E0040000 CID B105900D PID 000BB9A1 TPIU
[0][5]: E0041000 CID B105900D PID 000BB925 ETM
Cortex-M4 identified.

 

 

And here is a batch-script which will run recover continuously:

 RE: nRF52832 not connected anymore after first trying to debug (Keil) 

 

Kind regards,

Håkon

[jean-marc]

Håkon Alseth you are the Boss :-D

I had to do both.

J-Link commander at connect was going thru well as listed in the example above up to the last line. But the last line rather to say "Cortex-M4 identifies it says "Could not connect".

Then I ran "nrfjprog --recover -f nrf52" and it did connect. (last time it did not work).

Now I am OK and VScode can see my board and flash.

Now i have to find out why my code or the code suggested by the course does not work.

When I flash it it goes again disconnect and then when I run connect with the J-Link commander it works, and all is fine.

In any cases I know how to recover and I appreciate your excellent help.

[Håkon Alseth]

Glad to hear that it worked out! :)

If the firmware asserts early in the process, and the default behavior is to reset, it can be problematic to recover the board, as the firmware will effectively be in a reset-loop. This could have happened in your firmware.

 

PS: I would still recommend that you get a newer DK version. It is OK to use for evaluation, but you want to use a production grade silicon for development.

 

Kind regards,

Håkon