Enabling internal pull-up for nRESET on ANNAB402

[Lukas G.]

Hello everyone,

I'm currently working on a project wherewe use the ANNAB402 and Zephyr as out RTOS. We are developing using VSCode on a Linux VM. With a new board from us we had the problem, that the debugger of VSCode would not start anymore. We figured out, that on the previous version of the board we had an external pull-up resistor on the nRESET pin. Because of space on the board this resistor was removed, as was believed, that the nRESET pin would have internal pull-up activated by default.

I have tried to enable the internal pull-up in my overlay file, I was however unsuccessfull in getting the debugger to work. I would appreciate any help in trying to solve this through software implementation.

Kind regards,

Lukas

[Sigurd]

Hi!

That sounds strange. Maybe you can try this approach here:

 Enabling pin reset. Is still active even with CONFIG_GPIO_AS_PINRESET=n 

[Lukas G.]

Unfortunately this doesn't seem to fix my problem. I still get this error message:

[Sigurd]

Did you try measuring the voltage on the nRESET (P0.18) ? If yes, what voltage are you measuring ?

[Lukas G.]

I measured the Voltag at the pin for the J-Link adapter and it is at 1.8 V. So it seems, that the internal pull-up is working, but when I try to start the debugger, it has some other problem.

[Sigurd]

Hi!

1) And VDD for the ANNAB402  board is also 1.8V?

2) How did you launch the debugger session?

3) How does your "launch.json" file looks like?

4) Is it only the ANNAB402 you are having issues with? Are you able to debug e.g. a nRF52833-DK ? 

[Lukas G.]

Hi, sorry for the late reply.

1) yes, the VDD is 1.8V

2) I tried to debug it trhough the nrf Connect extension for VS Code ("Actions->Debug")

3

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "type": "nrf-connect",
            "request": "launch",
            "name": "Launch the active build configuration",
            "config": "${activeConfig}",
            "runToEntryPoint": "main"
        }
    ]
}

4) We have different Evalboard, with a different Layout. That board is working. I also tested a few boards of the same type, that I got this problem on and 1 also had this problem, 1 had this problem but after a paatch with an external pull-up resistor it worked and I also had one, that could start the debugger without the patch of the external pull-up.

We believe, that it might be a hardware issue rather than a code issue. So we will continue to test it and I will comment here, when we hopefully find the problem.

Thank you very much for the help,

Lukas