Can the nrf52840 USB dongle be (re)flashed via USB?

[daten]

As far as I understand, the nRF52840 USB dongle can be flashed via USB if there's a DFU capable bootloader installed (and it booted *into* that mode).

Once I got the dongle I was able to successfully do so. However I'm kinda lost with how to re-flash it - now it has (custom) software flashed, hence, not being in DFU mode anymore.

Is there actually a way of re-flashing the nRF52840 USB dongle - without hardware interaction (e.g. pressing a button) - once it's running custom firmware? Mentioned custom firmware is mine, so I can implement whatever needs to be implemented in case that helps making re-flashing via USB possible.

[Simonr]

Hi

Yes, this should be possible if you add the DFU Trigger Library to your application. It allows a connected USB host to remotely tell the app to reboot into the bootloader to allow it to be updated via DFU. Please see the Infocenter page for more information on this library. 

Best regards,

Simon