The Thingy:91, unlike our development kits, does not have a debugger on board. Therefore, the procedure for flashing firmware is different. In this short paragraph, we will show you what is needed to flash the Thingy:91.

1. Open the plastic covering.

2. Make sure the Thingy:91 is connected to your computer with a micro-USB cable.

3. Put the Thingy:91 in DFU mode by pressing SW3 while switching SW1 to the ON position. For this, you need to first power off the Thingy:91.

4. Open the nRF Connect for Desktop, then open the Programmer application as shown below

5. Click SELECT DEVICE 

Then, select the Thingy:91 entry from the drop-down list.

6. In the menu on the left, click Add file in the File section and select Browse. A file explorer window appears. Navigate to the build folder of your application <application root directory>\build\zephyr and select the file app_signed.hex .

7. Scroll down in the menu on the left and make sure Enable MCUboot is selected.

8. In the menu on the left, click on write. The MCUboot DFU window appears. Press on write in the MCUboot DFU window.

When the update is complete, a Completed successfully message appears