After write sniffer_nrf52840dongle_nrf52840_4.1.0 to nRF52840, Dongle doesn't work

[Arthur Xin]

[Device Name]: nRF52840 dongle

[Hex File]:  sniffer_nrf52840dongle_nrf52840_4.1.0.hex

[Error]:

21:21:54.487 Uploading image through SDFU: 96%

21:21:54.694 Uploading image through SDFU: 97%

21:21:54.713 Uploading image through SDFU: 99%

21:21:54.728 Uploading image through SDFU: 100%

21:21:54.849 All dfu images have been written to the target device

21:21:54.909 Target device closed

21:21:57.852 Failed to write: Error: Timeout while waiting for device C3612F7FE887 to be attached and enumerated (<--After writing)

21:48:36.821 Using @nordicsemiconductor/nrf-device-lib-js to communicate with target via USB SDFU protocol

21:48:36.844 Error when fetching device versions: readFwInfo error (Origin: "Error when starting nrfdl_fw_read_info") (<-- After select device 'nRF Sniffer for Bluetooth')

[Ref]

Programming the nRF52840 Dongle (https://infocenter.nordicsemi.com/topic/ug_nc_programmer/UG/nrf_connect_programmer/ncp_programming_dongle.html)

[Question]

Now my dongle doesn't work, what should I do?

[Arthur Xin]

I repair the issue by doing:

1. Open 'Bluetooth Low Energy' through 'nRF Connect for Desktop'.

2. Press Reset button.

3. Select 'Open DFU Bootloader', app will give hint 'Device must be programmed, do you want to proceed?', click 'YES'.

[Arthur Xin]

But I still cannot upgrade to sniffer tool.

[Arthur Xin]

 nRF52840 dongle, nRF Connect, Programmer, ERROR Reopen device failed 

Infact, the error log is correct after upgrading.

[Simonr]

Hi

This is the expected behavior, as when you flash any project onto your Dongle using the nRF Programmer app it will immediately leave the USB bootloader mode after the DFU is complete and start running the application flashed onto it. The nRF Sniffer for Bluetooth is not the same as the USB bootloader, so it won't be recognized by the nRF Programmer. In order to flash it with new firmware now you need to press the side-mounted button on the Dongle. This will put it back into bootloader mode, and let you flash new programs onto it.

Best regards,

Simon

[Arthur Xin]

Thanks very much for your answer, Simon.