Programming the nRF52840 Dongle

To program the nRF52840 Dongle, complete the following steps:

1. Open nRF Connect for Desktop and launch the Programmer app.
2. Insert the nRF52840 Dongle into a USB port on the computer.
   The status light LD2 turns on solid green, indicating that the dongle is powered up.

3. Put the dongle into bootloader mode by pressing the RESET button.
   

   

   LD2 starts pulsing red, indicating that the dongle is powered up and in the bootloader mode. After a few seconds, the computer recognizes the dongle as a USB composite device.

   Note

   • This step is not needed if the currently running application uses the DFU trigger library, part of the nRF5 SDK v17.1.0.
   • If this is the first time the dongle is connected, a driver needed for the nRF52840 Nordic Secure DFU feature is also installed as part of this step.

4. In the navigation bar in the Programmer app, click Select device and choose the serial number of the dongle from the drop-down list.

5. Drag and drop the HEX file into the File Memory Layout section. Alternatively, click Add file to add the files you want to program, using one of the following options:

   • Select the files you used recently.
   • If there are no recently used files, click Browse from the drop-down list.

6. Select the firmware image file (with the extension HEX) from the file browser that opens up.

7. Click Write to program the firmware onto the dongle.

When the writing process completes, the device resets, and – unless the application uses the DFU trigger library of the nRF5 SDK v17.1.0 – the dongle will no longer show up in the Programmer app, as it is no longer in the bootloader mode.