minivolumidi is a simple midi controller via wifi and rtpMIDI / apple network MIDI, based on a Wemos D1 mini (ESP8266) and a KY-40 rotary encoder that is intended to act as a volume controller. By default a short button press sets the CC value to the configured MIN_POS and a long button press sets it back to the value before the short button press.
You can find the whole documentation (for the software and the hardware part), the sourcecode, the 3d files and everything else on https://github.com/Apfelwurm/minivolumidi
Thanks to all the nice people making quick projects like this possible by their contributions to the open source world!