Air-Drum-Flute-Guitar

Its key aspects are:-

• A non-contact instrument supporting and encouraging movement and music.
• Instrument Selection
• Data log progress if required via the USB port.

The intended recipient is someone who could benefit from an interactive form of music and movement. The current solution was to combine aspects of the Medi-MIDI and the Mini Drum synthesizer along with a range finder of some sort. Therefore if student comes within range of the device, various percussion, chords or tones can be generated.The test bed was used to experiment with different sensors. I'd had some trouble with the ultrasonic (US) sensors picking up stray pulses so decided to try an infra red detector. These (for the moment) appear to lack stability as well as having a maxim range of 1.8m (in reality 1.4m usable). I returned to using the US range finder and experiment with different timing windows.and now have reliable results. The mini HIFI amp, Arduino processor, music shield, 9v battery box, green LED, speaker, instrument and mode selection switches are now being shoe-horned into the box above!

For a later version it would be nice to make it into a diminutive guitar shape. An additional idea is to simplify the controls and functions by using inboard tilt switches.

Processing Power

A standard Arduino (or Genuino) was used but cheaper open source equivalents can be used. e.g. A Hobby Components board can be had for around £5.00. N.B. With some of the open source "copies" you may need different drivers for the IDE to communicate with it

MIDI Generation

I've used the Sparkfun Music Shield. This is already configured to use the MDI standard and has proved reliable over the last couple of years. Initially I imported from the USA but they are now available via suppliers I have indicated elsewhere.

Range Finding

After experimenting with different range finders I settled on the ultrasonic version. These have a range of up to 4 meters but I have limited it to around 1 meter for the moment. The range is then subdivided into around 10cm sections to trigger different chords, tones or drums.

Mode Selection plus On / Off

Initially I was going to use an external infrared remote control to change modes and instruments. In the end I kept to onboard selection switches as it is more intuitive. This switch gives:-

[1] Off [2] On~Percussion [3] On~Chords [3] On~ Tones

Binary selection is used that is Highs and Lows are sent to the Arduino inputs. This save the extra wiring required for a resistive ladder network but uses more inputs (not a problem fro this project).

Instrument Selection

Again a rotary switch with binary selection is used. (Instrument yet to be finalised).

Power On Indicator

As this project is powered by an internal battery there is a need to indicate that it is switched on!

Speaker and Ultrasonic Rangefinder

The output from the speaker is checked to be within current limits of 85Db when held near the ear (UK standard).

Amplifier.

Almost any amplifier can be used. This one has the advantage of small size, volume control and can run off 6-15v. It is worth checking that the voltage range fits in with the other components used (I have been caught out this way a couple of times).

Air Guitar Drum ~ Nearly There.

All the components have had their leads soldered on. The final hardware stage is connecting up the the music shield / arduino.