MCUboot Device Not Entering Bootloader Mode nRF 52840 Dongle

[Think_big_91]

After flashing the nRF Sniffer for Bluetooth on nRF52840 dongle, I want to flash it back with the programmer to use it in the nRF Connect App but it wont go in boot mode.

After I selected it in the programmer I tried also pressing the physical button for the reset but it wont enter bootloader.

"If the device is a MCUboot device make sure it is in the bootloader mode"

"No operations possible for device."

Is there a workaround solution for this?

[Hieu]

Hi Think_big_91,

Could you please try to hold the reset button as you plug the dongle in?

Hieu

[Think_big_91]

I have tried holding it, but it's the same result. Wont go into boot mode

[Hieu]

This is odd. I have switched my dongle between sniffer, connectivity firmware, and custom projects many times. The switch button always works.

Software wise, it is not really possible to break the bootloader functionality.

Could you please confirm that you are pressing the side-mounted RESET button, and not SW1?

Refer to Programming (nordicsemi.com).

[Think_big_91]

It appears that the problem was due to pressing SW1 instead of the side-mounted reset button. It's more intuitive to press the SW1 since also the RESET is printed on the board near SW1. Thank you for your patience. This solved the "issue"