Enter DFU mode battery-powered not working

RE: Enter DFU mode battery-powered not working

Vidar Berg — Thu, 21 Oct 2021 08:01:17 GMT

Ah, the devices was actually shutting down. My assumption was that the FW was entering a "bad state" and got stuck. Thank you for the update.

Best regards,

Vidar

RE: Enter DFU mode battery-powered not working

John1 — Wed, 20 Oct 2021 18:45:44 GMT

Hi Vidar,

Thanks a lot for your help. Using this knowledge I found out that a pin was configured in the wrong way. A specific gpio pin should have been initialized as output pin and set to one, otherwise my device simply shut down. so I had to adapt my code to deal with that. My problem is solved now.

Best regards,
John

RE: Enter DFU mode battery-powered not working

Vidar Berg — Thu, 14 Oct 2021 15:32:05 GMT

Hi,

Great that you have GDB setup ready, that will make further debugging easier if it becomes necessary.

Yes, you can use "info registers" to read out the registers. The most interesting one now is probably the Program counter (PC). It will tell us where the CPU is executing code from. Based on its address range you can determine if it hangs somewhere in the application or in the bootloader.

Edit: try to configure gdb to connect to a «running target». Because if you connect and reset it might recover the device.

RE: Enter DFU mode battery-powered not working

John1 — Thu, 14 Oct 2021 15:06:26 GMT

Hi Vidar,

Nevermind, thanks for your answer! I am not aware of any command line tool specific for that debugger.

Yes, I have GDB running by following and adapting the following tutorial: https://medium.com/makerdiary/debugging-nrf52-boards-with-visual-studio-code-c1482a759997

I assume now I have to use the command "info registers" to have a look at the registers, right? Which ones are of importance here?

RE: Enter DFU mode battery-powered not working

Vidar Berg — Thu, 14 Oct 2021 12:04:44 GMT

Hello John,

Sorry, I forgot that you were using another debugger. nrfjprog only works with J-link programmers. Is there compatible command line tool for this debugger you can use to read the CPU registers. Alternatively, do you have a setup for debugging with GDB, etc?

Best regards,

Vidar

RE: Enter DFU mode battery-powered not working

John1 — Wed, 13 Oct 2021 15:23:59 GMT

Hello Vidar,

After installing nrfjprog I tried running your command with no success:

As written above I use the Particle Debugger (see here for an image of this debugger: https://github.com/particle-iot/debugger) to connect my board to the PC via USB. I currently use pyocd to flash the soft device and application, which works fine. I am not 100% sure, but I think pyocd flashes the .hex files using CMSIS-DAP currently. Is there something I have to change in order to be able to use nrfjprog? Or is there an alternative I can use to read the registers?

Best regards,
John

RE: Enter DFU mode battery-powered not working

Vidar Berg — Thu, 07 Oct 2021 11:11:39 GMT

Hello,

I can't think of any obvious reasons for this. After the device is "turned off", could you try to attach the debugger again and read the CPU regs with nrfjprog --readregs to find out what state the chip is in?

Best regards,

Vidar