No ping response after opening COM port error

[Prathik]

This is the error I have. Couldn't figure out what causes this error. Tried all the related issues mentioned on this website.
I have made sure the python and latest version pip is installed.
Trying serial update on Windows. I use Adafruit Feather nrf52840 board. I have also read that double clicking reset button enters the DFU mode. When I tried it, I could see led continuously glowing and a drive is visible on my PC. I have tried it several times. But suddenly stopped. Double clicking the reset button doesn't make the led glow and i can't see the drive.  

Please let me know what I can do to make this work. Thank You.

[Prathik]

Hello. Sorry for late reply.
The MBR hex is already present.

C:\Users\nishi>nrfjprog --readregs
R0: 0x00000000
R1: 0x00000000
R2: 0x00000000
R3: 0x00000000
R4: 0x00040003
R5: 0x20001E00
R6: 0x10001000
R7: 0x000FE000
R8: 0x00000000
R9: 0x00000000
R10: 0x00000000
R11: 0x00000000
R12: 0x2003A73D
SP: 0x2003FFD8
LR: 0x0002B6DD
PC: 0x00027720
xPSR: 0x61000000
MSP: 0x2003FFD8
PSP: 0x00000000

I dont know how to check this. Please let me know how I can check whether the device goes to bootloader mode or not.

Thank you.

[Vidar Berg]

Hello,

The Program counter (PC) shows that the CPU is executing code inside your main application and xPSR shows that it's not running in any interrupt context. Unfortunately, it doesn't help explain why your board is not entering/staying in the bootloader DFU mode on startup.

Could you try to view the memory layout if your device with the nRF connect for desktop app just to make sure everything looks to be as expected?

Also, check the if the bootloader address stored at the following 2 addresses matches the actual bootloader address displayed in the nRF connect app:

[Prathik]

The bootloader file is a zip file that I have to use for updating by Serial using nrfutil. It contains bin and dat file. So I cant drag and drop that file.

[Vidar Berg]

Thanks. I see the bootloader start address is stored correctly (@0xFF8/0x10001014). This means your bootloader will get executed after a system reset. So the question now is why it always jumps to the main app instead of entering DFU mode.

I suspect it must have something to do with the bootloader configuration. Do you know if it was built with the NRF_BL_DFU_ENTER_METHOD_PINRESET config setting enabled or not?

[Prathik]

Thank you for your response.
I tried erasing the board and flashing softdevice file and running the bootloader program. Then used the nrfutil command. This also didn't work. I'm trying to do it without main application.
I also got a nrf52840 DK .I tried with board with default 5,6,7,8 pins for RTS, Tx, CTS, RX. It's not working on this board also. Got "No response after opening COM port" in command prompt.