nRF Connect Programmer v1.4.1 or later

Programming applications through USB (MCUboot)

You can program either the nRF9160 System in Package (SiP) or the nRF52840 System on Chip (SoC) of Nordic Thingy:91™ through USB by putting the device into serial recovery mode.

The component to be programmed is determined by pressing and holding the SW3 or SW4 button while powering on the device.

Note: To update the nRF52840 SoC on the Nordic Thingy:91 HW v1.0.0 (see white label on PCB), perform the steps as described in Programming applications through an external debug probe.
To program a Nordic Thingy:91 through USB (MCUboot) and the built-in serial recovery mode, complete the steps in this section.

  1. Open nRF Connect for Desktop and launch nRF Connect Programmer.
  2. Connect Nordic Thingy:91 to the PC with a micro-USB cable.
  3. Power on Nordic Thingy:91 and put the device into application serial recovery mode by pressing and holding the SW3 or SW4 button while powering on depending on whether you want to program the nRF9160 SiP or the nRF52840 SoC.
    See the following image to locate the buttons.
    Figure 1. Nordic Thingy:91 buttons
    Nordic Thingy:91 buttons
    In the navigation bar, No devices available changes to Select device.
  4. Click Select device and select the device from the drop-down list as shown in the following figure.
    Connecting to the Nordic Thingy:91 using nRF Connect Programmer
    You can identify Nordic Thingy:91 by confirming that the PCA number displayed in the drop-down list is PCA20035 and there are two visible COM ports. If the two COM ports are not visible, it could be because of the following reasons:
    • When Nordic Thingy:91 is reset while it is still connected to the Programmer app. Press Ctrl+R in Windows and command+R in macOS to restart Programmer and to correctly view the COM ports.
    • Other errors.
  5. Drag and drop the HEX file into the File Memory Layout section. Alternatively, click Add HEX file on the right pane (named as File) to add the files you want to program, by 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
    Selecting the firmware image file using Add HEX file option in the nRF Connect Programmer
  6. Select the MCUboot compatible firmware image file (with the extension .hex) from the zip file that you have downloaded from the Nordic Thingy:91 Downloads page, using the file browser that opens up.
    Note: A normal firmware image HEX file cannot be used when programming applications through USB, since the MCUboot bootloader is used. The HEX file needs to contain the application at the appropriate memory offset for use with MCUboot. See the CONTENTS.txt file in the extracted folder for details of the MCUboot compatible firmware image file.
  7. Click Write on the Device pane in the right as shown in the following figure.
    Updating the application firmware using Write option in nRF Connect Programmer
    The MCUboot DFU dialog box appears as shown in the following figure.
    MCUboot DFU dialogue box
  8. Click Write in the MCUboot DFU dialog box to program the device.
    When the update is complete, you see a success message.