Nrf52840 dongle cannot enter reset mode

[Geass77]

Dongle cannot enter reset mode, and led  is not pulsing(no shine ) when I  connect to PC, the device cannot detect it,too. Is their any problem on the firmware, the device cannot detect it,too. Is their any problem on the firmware, or it was just broken?

[Amanda Hsieh]

Hi, 

The simplest way to program the dongle is to use the nRF Connect for Desktop and launch the Programmer app:

1. Open nRF Connect for Desktop and launch the Programmer app.
2. Press the reset button to put the Dongle in DFU mode. This is not needed if the currently running application uses the DFU trigger library. Note that the reset button is the sideways button right next to the more obvious SW1 button on the Dongle:
   
3. Select the dongle in the dropdown in the upper left corner if it is shown.
4. Click "Add HEX file" to select the application hex file to program onto the dongle.
5. Click "Write" to write the firmware to the dongle.

Please also see this tutorial. 

-Amanda H.

[Geass77]

When I press  reset button, my dongle doesn't have any response, my programmer cannot detect it too

[Amanda Hsieh]

Did you really press the reset button which is the sideways button right next to the more obvious SW1 button on the Dongle?

-Amanda H.

[Geass77]

yes,small one

[Amanda Hsieh]

Hi,

Do you see LED2 flash with the red light after pressing the reset button?

Geass77 said:

When I press  reset button, my dongle doesn't have any response, my programmer cannot detect it too

Do you use the nRF Connect for Desktop/Programmer app?

-Amanda H. 

[Geass77]

not flashing, nrfconnect doesn't have any response

[Amanda Hsieh]

Hi, 

Have you soldered and connected an external debugger, and erased all flash(including bootloader)?

Could you try other USB ports on the PC or other PC?

-Amanda H.