Software

The USB microcontroller used in the FiiO KB3 has open-source firmware support although FiiO does not make it immediately obvious. It's not mentioned on the English version of the website and I had to go through the Chinese version as well as the FiiO forum to find this link that helps download the JSON file enabling VIA to recognize the keyboard. Note that there is no QMK compatibility though, and I would certainly have preferred to not jump through all these hoops. Thankfully, VIA is quite nice and we've seen it used before to good effect. You can go to the online VIA configurator or download the latest release off Github if you want to have something installed on your PC. I've tested both approaches and they work the same, although the installed program can be slightly faster with more complex firmware loadouts and saves. Load the JSON file and VIA will gain access to the keyboard as long as it is already plugged into your system.

Anyone who has used VIA before already knows what to do, although I will point to this video which will work as a decent tutorial/starting point for those new to it. The video above also quickly walks through using the keyboard with VIA, including with the various layers on offer as well as the extensive key mapping options. Notice how providing access to the keyboard automatically pulls up the default key map for all the 81 keys on board as well as the volume control wheel. We also see the pre-programmed layers, two of which have enough empty/duplicate slots for you to fill out as needed. There are plenty of key assignment options, macro recording/editing, as well as control over the LEDs on the PCB. Some community members also have separate tools with more lighting effects based on VIA if you wanted to go beyond what's available here—just take your time and step down the VIA rabbit hole slowly.