Resetting nRF52840

[Yash.P]

We would like to reset or factory reset or initial flashing of nrf52840dk? We tried pressing RESET button during power cycle, but did not worked. Let us know your thoughts.

The DK is going into boatloader mode. Even the led5 is not blinking while reset.

[Samruddhi Jadhav]

Hi,

If you are trying to simply reset, then I would suggest that you use the IF BOOT/RESET (SW5) button. To use this, make sure that pin P0.18 is set as reset pin by your firmware (CONFIG_GPIO_AS_PINRESET) and then try to reflash. An alternative is to run nrfproj --pinresetenable and re-flash. 

Pressing IF BOOT/RESET (SW5) during power cycle, is used to interface MCU bootloader (LED5 blinks to indicate this) not to factory reset. If LED5 isn't blinking, it may be due to the button not being held long enough to detect bootloader or interface MCU has a working J-link firmware. 

If you want to fully erase or "factory reset", I would suggest using SWD and tools such as the nrfproj --recover command. This will then trigger ERASEALL meaning all flash contents get removed. You can then program again and reset. 

Hope this helps.