PComp

Curious Light, Final - Evil Groundhog

Arduino Musical Keyboard Examples

MakerShed PocketPiano Shield



This is a pre-made Arduino shield/kit, with enough pushbuttons to play two octaves ($50). The following components are built-in:

• 25 multiplexed keys (for 2 octaves)
• 4 pots,
• status LED,
• reset switch,
• digital to analog converter IC,
• RCA audio jack

There is an opensource "synth engine" code library called Arduino Piano Squealer Synth which uses the above kit.


"Software Programmer Dreams of New, Small Music Machines"

The first image in this article shows an array of 13 pushbuttons connected to the 13 digital pins of the Arduino, which is just enough for playing a full octave of notes.



Further down in the blog post is a video showing a completed enclosure with 4 pots controlling various effects, similar to the pre-made kit above.


PaperTeclado: A keyboard with a printed sheet of paper (Spanish)

This one is the most modest: Two printed strips of paper covered with inkjet ink are layered on top of each other. When contact is made between the two strips, it creates varying levels of resistance. The Arduino then generates discrete tones thru a connected speaker based on the level of voltage read.

Toy teardown

Cat toy:

Underside with manufacturer markings; on/off switch:

Rod + feather, detached

Battery cover, which includes counterweight:

In two halfs, plus some weight:

Another weight:

Housing with motor in it:

 

Top cover of motor housing, detached

Gears inside housing. White goop:

Motor, naked:

Motor, naked, other side:

Motor housing, with motor re-placed inside of it:

Maker Faire

Bone Conductor Mechanical Orchestra
Nick Yulman

An interactive mechanical piece where various found objects are used for their musical potential as instruments of percussion. A laptop controls the timing of the many servos that are attached to sticks and other things that hit things like boxes, tins, and a real drum to create music. The artist also sets up his piece in installations and even can play live. Exploring the musical potential of found objects through computing is a great way of mixing the digital with the "analog."

 

Electric Chaircut
Nelson 

Audio sensors are connected to scissors as the artist/barber cuts people's hair, on-site at the event. The sound is routed through effects pedals and played through an amplifier mounted on a harness on the artist's back. It's applied musical performance art. Musically, it sounds very industrial, or "Sonic Youth"-esque maybe; lots of feedback and reverb, and in general, creating a strange and likeable experience. My favorite piece at Maker Faire.

 

Beatbox and Bicycle Wheel
Adam Matta

A "scratching" instrument, but instead of a turntable, using a bicycle wheel; instead of the grooves of a vinyl record, real magnetic tape from an audio cassette; and instead of a record needle, the playhead of an old Walkman. The source audio was taken from AM talk radio, recorded with a cassette recorder. Best of all, the bicycle wheel scratching apparatus is mounted on a stool a-la Marcel Duchamp.  A thoroughly analog experience.

All the pieces I chose above are musical - even though the artistic/technological interests I have pursued up to this point have been almost exclusively visually oriented and heavily "algorithmic" in nature. It's obvious that it's time I branched out...

 

Mood Light Upgrade

• The mood light now alternates between 2 green and 2 blue LED's using a very slow crossfade over the course of about 45 seconds (It still brightens and dims very gradually in response to the change in ambient light)
• The main body of the enclosure is now sealed, and the top now comes off very easily as one unit.
• The light sensor is now housed within the enclosure, as is a battery pack.
• The LED's are now diffused using styrofoam balls

The above video primarily demonstrates the slow change in color from green to blue and blue to green.

CODE

Ziggurat Mood Light

Three green LED's in a ziggurat-shaped cardboard enclosure react to a light sensor by slowly increasing in brightness as ambient light dims, and vice-versa.

 
I noticed that when the LED's are lit in their lower brightness range, the apparent change in brightness was very noticeable as they changed in 1-increment steps. In order to make the change in light intensity appear smoother (especially since I am tweening their values slowly), I stagger the values of the 3 LED's over time in this kind of pattern --

0,0,0 | 0,0,1 | 0,1,1 | 1,1,1 | 1,1,2 | 1,2,2, | 2,2,2 | 2,2,3, etc

-- rather than applying the same incremented integer value to all three LED's simultaneously...