Breath-Controlled MIDI Flute

Electronic music and the MIDI protocol has revolutionized music production, and electronic instruments abound in every size and shape. Nominally you use your hands to control such instruments (like a keyboard), and perhaps a foot or two (e.g. a keyboard sustain pedal), but what about using your breath in a similar manner to a wind instrument? As outlined here, Crius Digital Studio has come up with a way to add such control via a sphygmomanometer (blood pressure cuff) sensor.

This device, dubbed the Crius MIDI Flute, consists of three panelized PCBs that form a roughly flute or recorder-like configuration. The PCB segment closest to one’s mouth holds the MPS20N0040-D pressure sensor and an LM358P op amp. This sensor setup, along with a segment of tubing, enables the user to produce air pressure from one’s mouth to control the velocity of the notes being played.

Below the pressure sensor unit, 12 buttons on the second PCB segment act as finger note controls. The final segment features an Arduino Pro Micro board, plus a pair of small tactile buttons that change the octave being played. The Pro Micro sends signals to a computer or other audio hardware via the MIDI protocol, allowing it to make beautiful flute sounds – or anything else you have it set up to play.

The Crius MIDI Flute does not produce sound on its own, and needs to be connected to other audio components, though one could certainly produce such an instrument (or other interface device) using this pressure sensor concept. The video (in Greek) shows the build process, as well as footage of it in action at the beginning and at around the 18:45 mark.