How to enter DFU Mode

[Siva Subrahmanyam]

Apart from pressing Button 4 or adding a DFU service to current running application. Is there any way to enter DFU mode from application?

Is it possible with nrfutil to move from application to DFU Mode, Update the image.

[John]

The short answer is yes. The newer SDKs provide some very nice features for entering the bootloader without a button or even a reset. Which allows sharing of bonding information, or avoiding bonding being an issue for the bootloader. That said, you don't have to use all of that. In our case we didn't need the functionality and in fact it was causing some problems due to the fact that there wasn't a system reset to stop other portions of our system. So, I simplified bootload entry to just setting the GPREGRET register and doing a system reset. It required changes in the bootloader, but you have the source code so you can modify it to your needs.