The nanoPi is a DIY synth project, based on the Raspberry Pi microcomputer. It combines a raspberry Pi Zero W, 10000mAh battery, and a Korg nanoKEY2 into a single portable synthesizer.
Because it runs on a raspberry Pi, the possibilities for software are open. This build is based on fluidsynth. The video also demonstrates how to use a phone as a controller to change instruments and other settings.
The synthesizer also features external USB inputs, which allow it to be controlled by external MIDI devices. Additionally, the device works in MIDI mode to control a computer and even doubles as a battery to charge a phone or other devices.