I originally developed this firmware to try out the Miryoku layout without having to install its development environment with several hundred megabytes. The PicoSplit firmware certainly has fewer features than some other firmware, but it comes with everything for configuration. You don't have to install additional software on your computer. A simple text editor and a web browser is all you need. Since the firmware can also be used to create other keyboards, I provide it on Github for free under the MIT license.