Programming applications through an external debug probe

You can program either the nRF9160 System in Package (SiP) or the nRF52840 System on Chip (SoC) of Nordic Thingy:91™ by using an external debug probe.

For programming the applications, you must use an external debug probe such as nRF9160 DK or J-Link device supporting Arm® Cortex®-M33. To program a Nordic Thingy:91 using an external debug probe, complete the steps in this section.

1. Open nRF Connect for Desktop and launch nRF Connect Programmer.
2. Set the SWD selection switch (SW2) on Nordic Thingy:91 to nRF91 or nRF52 depending on whether you want to program the nRF9160 SiP or the nRF52840 SoC. See SWD Select for more information on the switch.
3. Connect Nordic Thingy:91 to the debug out port on a 10-pin external debug probe, for example, nRF9160 DK, using a 10-pin JTAG cable as shown in the following figure.
   Figure 1. Connecting Nordic Thingy:91 to the external debug probe

   
   Note: If using nRF9160 DK as the debug probe, make sure that VDD_IO (SW11) is set to 1.8 V on the nRF9160 DK.
4. Make sure that Nordic Thingy:91 and the external debug probe are powered on.
5. Connect the external debug probe to the PC with a micro-USB cable.
   In the navigation bar, No devices available changes to Select device.
6. Click Select device and select the appropriate debug probe entry from the drop-down list.
   You can identify the nRF9160 DK by the fact that it has three COM ports. If the three COM ports are not visible, it could be because of the following reasons:

   • When the nRF9160 DK 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.
   The button text changes to the SEGGER ID of the selected device, and the Device Memory Layout section indicates that the device is connected.
7. 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.
8. Select the 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.

   Check the CONTENTS.txt file in the extracted folder for the details of the compatible firmware image file.

9. Click Erase & write in the Device pane to program the device.