Locked nRF52840 DK board

[p143]

Hi All.

Practising Secure DFU, my nRF52840 DK board seems like if it is locked. Only Leds 1 and 2 are ON. The board is advertising with DEVICE_NAME=Dfu Targ and its COM serial communication is lost. If I press the reset button SW5, nothing happens. If I press the reset button (SW5) while power cycling, the board enters in bootloader mode, but appart from this, nothing seems to change. If I try to access the board via nRF Connect, when I try >Select Device my PCA10056 is not being detected. Summarizing. I need an HW full reset procedure.

Does anyone know how to do it?

Thanks for your time.

Regards

Juan

[Hung Bui]

Hi Juan, 

Yes on the first time when the bootloader see no application it will by default enter bootloader mode. But when you have your app running, you need to enter the bootloader mode, either by holding a button when booting, or by using DFU buttonless service to receive a command in BLE. 

You can find the DFU buttonless example in \examples\ble_peripheral\ble_app_buttonless_dfu and can find the documentation here. 

[p143]

Extremely clear, Hung.

Thanks for this comment and have a nice weekend.

Juan