NRF52 (Custom Board) Serial DFU Reset the device.

[sonalkale]

Hello,

I am using SDK 12 with softdevice 130.I can successfully use DFU OTA and Secure using nordic development board.

While using our custom board(without Buttons) we can use DFU OTA successfully.

But In DFU serial our custom board gets RESET when it switch to DFU mode and start advertising as previous.

Same program with same procedure works fine on NRF52 development kit.

Please suggest any solution..

Thanks.

[MartinBL]

Hi,

I'm not sure if I understand.

Your are doing DFU over UART, and it works on a development kit, but not on your custom board?

When the device resets it is likely that your code has hit an assert. Have you tried to debug and look for such asserts? Is it possible that the UART fails on your custom board?

 

[sonalkale]

Hello,

   Yes,it works on a development kit, but not on custom board.In my program it switch to bootloader mode when it receive specific character(in my case "@") from bluetooth device or from serial port.

When we receive "@" from bluetooth its reset the board...Actually its switch to bootloader mode but reset within a second.

[MartinBL]

So it sounds like you need to debug the bootloader. It resets for a reason and by debugging it might be possible to figure out why. Debugging a bootloader is not as straight forwards as debugging an application, but here are the steps you need to follow: https://devzone.nordicsemi.com/f/nordic-q-a/4101/bootloader-debugging.

When an application works on a devkit, but not on custom hardware, the usual suspect is the low frequency clock. Are you using an external 32 kHz crystal on your custom HW? Can you verify that it is working properly? Can you upload your schematics and layout files (preferably in Gerber or Altium format)?