MIDI & DMX PROTOCOLS

A (short) introduction by P.-A. Poirier

How the MIDI protocol works

MIDI stands for musical instrument digital interface

One basically needs 3 things:Something to generate sounds, an input device and a sequencer to record/replay the MIDI inputs.

SEQUENCERWhat records the data

INPUT DEVICEThe input devices are typically MIDI-enabled

SOUND GENERATORWhat outputs/play the sound(s)

How the MIDI protocol works

MIDI stands for musical instrument digital interface

One basically needs 3 things:Something to generate sounds, an input device and a sequencer to record/replay the MIDI inputs.

SEQUENCERWhat records the data

INPUT DEVICEThe input devices are typically MIDI-enabled

SOUND GENERATORWhat outputs/play the sound(s)

How the MIDI protocol works (2)

SEQUENCER / SOUND GENERATORGarageBand, Logic, Ableton Live, Max/MSP, Protools, Reason, etc.

INPUT DEVICEMostly synthesizers.

How the MIDI protocol works (3)

How the MIDI protocol works (3)

The neat thing about MIDI is that you don’t record actual sounds, you record data that (can) create sound.

So, in essence, you don’t need to be a musician—or air—to record music with MIDI. You can also change the (synthesized) instrument that plays the recorded data at will, and change that data (i.e. not replay a part, simply change data in MIDI-enabled software).

Elements that can be comprised in a MIDI data transfer:– pitch– intensity– volume– vibrato– panning– tempo

A Curious Audiovisual Sequencer For Simple Humansby Roberto Christen (IxD 2009)

What is DMX?

DMX is a protocol that is, says Wikipedia, “[…] most commonly used to control stage lighting and effects”. In a more general perspective, it is used in the visual effects that are used by the cultural / show-business industry; namely, it can trigger fog machines, lights, controllers, dimmers, etc.

One of DMX’s qualities is it’s robustness.

Console XLR cables Light

XLR connectors

(XLR–3 shown below)

Tinkerkit™ DMX Shield & Interface

http://tinkerit.myshopify.com/collections/lighting-solutions

The DmxSimple library to control DMX via Arduinohttp://code.google.com/p/tinkerit/wiki/DmxSimple

The Tinkerkit™ DMX Shield The Tinkerkit™ DMX Interface

Art-Net

“Art-Net then is a way of sending DMX information over IP networks.”

Basically it is using ethernet cables (which can carry more data) and / or wireless data transmission. It isn’t as robust as normal DMX/SLR cables (which are quite sturdy).

http://www.artisticlicence.com/WebSiteMaster/User%20Guides/art-net.pdf

References

MIDIhttp://www.midi-classics.com/whatmidi.htmhttp://www.midi.org/http://leftandwrite.com/brian/music/beginners_guide_to_midi.phphttp://en.wikipedia.org/wiki/MIDI

DMXA neat example of DMX integration with Arduino + Tinkerkit: http://www.vimeo.com/3453833DmxSimple library (for Arduino): http://code.google.com/p/tinkerit/wiki/DmxSimpleArtnet: http://www.artisticlicence.com/WebSiteMaster/User%20Guides/art-net.pdfArtnet + vvvv: http://www.vvvv.org/tiki-index.php?page=DMX.Artnethttp://en.wikipedia.org/wiki/DMX512-A

Miscellaneous

Arduino (especially under the ‘Playground’ section): http://arduino.cc/vvvv: http://vvvv.org/Processing: http://processing.org/Max/MSP/Jitter: http://cycling74.com/Ableton Live: http://www.ableton.com/Apple Logic: http://www.apple.com/logicstudio/Digidesign Pro Tools: http://www.digidesign.com/Propellerhead Reason: http://www.propellerheads.se/