Update via BOSSA GUI App
The fastest and easiest way to update the firmware of a DT Stellar is to Update via DT Nexus. In this case all connected Stellars are updated at the same time, and if you’re already connected by ethernet to DT Nexus no additional cables are required.
However, in the case that DT Nexus is not practical for you, the firmware of a DT Stellar can be updated using the BOSSA GUI app.
Steps
Connect to the light via USB-Micro.
Many USB-Micro cables, such as those provided with many headphones or other consumer electronics, are power-only and will not work. A “data transfer” USB-Micro cable must be used. For example these cables from Amazon.
Download BOSSA_GUI for your OS from github.com/shumatech/BOSSA/releases
On MacOS you may need to right click on the app, hold option, and click open to get around Apple's verification checker.
Click browse to locate and select the file firmware file (e.g. UPDATE.bin)
In the dropdown labeled Com Port select the item labeled ”...MKRZERO”
If there are more than one, select the one that says “TTY”
Make sure Erase, Verify and SAMD21 are checked
Click Upload Binary