J-Link connection lost after a few seconds

RE: J-Link connection lost after a few seconds

Jared — Fri, 16 Sep 2022 10:58:53 GMT

Hi,

[quote user="kostathan"]Thank you for all the help. Problem solved. I connected the DK to another PC and everything seems to work just fine now. I thought that the PC played no role in the matter, since my other DK worked just fine with the same PC.[/quote]

I'm very happy that you were able to solve the problem, also note that testing on another computer is step 3 in the thread I shared earlier 🙂

I'll close this case then,

Have a good weekend!

regards

Jared

RE: J-Link connection lost after a few seconds

kostathan — Fri, 16 Sep 2022 10:02:33 GMT

Hey Jared!

Thank you for all the help. Problem solved. I connected the DK to another PC and everything seems to work just fine now. I thought that the PC played no role in the matter, since my other DK worked just fine with the same PC.

Anyway, thanks again,

Kostas

RE: J-Link connection lost after a few seconds

Jared — Thu, 15 Sep 2022 09:19:11 GMT

Hi,

I'm not sure what is causing this. How have you supplied the board earlier? Was it always through the J2 USB header?

If you want, I can take a look at your board if you want to send it to us.

regards

Jared

RE: J-Link connection lost after a few seconds

kostathan — Wed, 14 Sep 2022 08:36:29 GMT

Hello again.

SW10: OFF

SW8: ON

SW9: VDD

SW6: DEFAULT

I believe that reset is activated, since I can put the kit in bootloader mode with IF BOOT/RESET button.

[quote userid="73165" url="~/f/nordic-q-a/91812/j-link-connection-lost-after-a-few-seconds/385926"]Can you elaborate on this? Are you using a stand alone debugger?[/quote]

Normally, I use the DK with a USB. Recently, I was provided with Segger's J-Link EDU module to check its debugging capabilities. Now the DK doesn't work either with the USB or with the module. There aren't any problems with the debug probe, since my other DK has worked perfectly with it. Could the problem have been caused by a forced PC reboot that happened while the DK was connected to the PC?

RE: J-Link connection lost after a few seconds

kostathan — Tue, 13 Sep 2022 12:23:42 GMT

Hello again.

[quote userid="73165" url="~/f/nordic-q-a/91812/j-link-connection-lost-after-a-few-seconds/385926"]Have you modified any of the solder bridges on your DK[/quote]

I haven't modified anything on my DK. The state of the switches is:

SW10: OFF

SW8: ON

SW9: VDD

SW6: DEFAULT

I believe that reset is activated, since I can put the kit in bootloader mode with IF BOOT/RESET button.

[quote userid="73165" url="~/f/nordic-q-a/91812/j-link-connection-lost-after-a-few-seconds/385926"]Can you elaborate on this? Are you using a stand alone debugger? How have you connected the DK to your computer?[/quote]

RE: J-Link connection lost after a few seconds

Jared — Tue, 13 Sep 2022 11:10:48 GMT

Hi,

Maybe the pin RESET feature isn't activated in your project. In that case, the pin would just act as a normal GPIO, which would explain your measurements.

Have you modified any of the solder bridges on your DK and can you list the state of the following switches:

SW10
SW9
SW6
SW8

[quote user=""]Two days ago, I was able to connect it to my PC and download and debug code naturally. I was even able to use the J-Link EDU kit normally, with both the 19-pin and the 9-pin Cortex-M adaptors.[/quote]

Can you elaborate on this? Are you using a stand alone debugger? How have you connected the DK to your computer?

regards

Jared

RE: J-Link connection lost after a few seconds

kostathan — Tue, 13 Sep 2022 09:32:00 GMT

[quote userid="73165" url="~/f/nordic-q-a/91812/j-link-connection-lost-after-a-few-seconds/385852"]This is very strange. RESET should be pulled high, if it's low then the nRF52840 is kept in RESET state. Can you try to pull it high by connecting VDD to RESET and see if it "wakes up" the board.[/quote]

So, something pretty strange is going on. I am listing the voltage measurements I made:

VDD-GND = 2.98V

RESET-GND = 0

VDD-RESET = 0 (I don't know how the last 3 can be possible at the same time)

5V-GND=5.01V

5V-RESET=1.61V (So reset is definitely at high)

5V-VDD=2.01V

All the above seem chaotic. I also tried to connect the VDD with RESET and nothing happened.

RE: J-Link connection lost after a few seconds

Jared — Tue, 13 Sep 2022 07:39:34 GMT

Hi,

[quote user="kostathan"]The VDD voltage of the kit is at 2.98V(VDD-GND) and the RESET pin's voltage is 0 (RESET-GND). What baffles me is that the voltage difference between the RESET pin and the VDD pin also appears to be 0.[/quote]

This is very strange. RESET should be pulled high, if it's low then the nRF52840 is kept in RESET state. Can you try to pull it high by connecting VDD to RESET and see if it "wakes up" the board.

regards

Jared

RE: J-Link connection lost after a few seconds

kostathan — Mon, 12 Sep 2022 18:41:00 GMT

Hi again! The "nrfjprog --recover --log" command returns

The VDD voltage of the kit is at 2.98V(VDD-GND) and the RESET pin's voltage is 0 (RESET-GND). What baffles me is that the voltage difference between the RESET pin and the VDD pin also appears to be 0.

Do you have any idea on how to proceed?

RE: J-Link connection lost after a few seconds

Jared — Mon, 12 Sep 2022 14:06:36 GMT

Ok, so the computer is able to communicate with the onboard debugger which is good. However, it fails when you try to recover. Can you add the log argument to the recover command:

nrfjprog --recover --log

and share the log?

Also, can measure the voltage on the RESET pin and the VDD pin on your DK.

regards

Jared

RE: J-Link connection lost after a few seconds

kostathan — Mon, 12 Sep 2022 13:27:35 GMT

Hello! Thank you for your response!

I run the commands you suggested and the device is listed normally.

I also followed the steps in the thread you sent (except for the voltage measurement) and nothing worked.

The first step suggested to check the device manager. In the device manager the device's port is listed as "JLink CDC UART Port" and its drive as "SEGGER MSD Volume USB Device".

I also tried to recover the kit with the nrfjprog --recover --log command and this was returned.

Should I try the manual recovery shown here? Are the commands for the nrf52 the same?

Thank you in advance!

RE: J-Link connection lost after a few seconds

Jared — Mon, 12 Sep 2022 11:39:57 GMT

Hi there,

If you use nRF Command Line Tools, and run:

nrfjprog --ids

Is the kit listed? If not, what error is returned by the program?

Could run the command again with the log attached?

nrfjprog --ids --log

Can you share the log?

Also, could you go through the steps listed in this thread and verify that none of the suggestions mitigated your issue?

regards

Jared

RE: J-Link connection lost after a few seconds

kostathan — Fri, 09 Sep 2022 10:22:09 GMT

P.S. I have another DK and it connects normally to the PC, so its not a cable or PC problem.