midi

276 Articles

Harmonicade Is A High-Scoring MIDI Controller

January 29, 2020 by 11 Comments

When [KOOP Instruments] started learning the piano, he wasn’t prepared for the tedium of learning chords and their relationships on the standard keyboard layout. But instead of killing his desire to tickle the ivories, it inspired him to explore alternative layouts that are easier to play. He converted to Isomorphism, started building MIDI controllers, and hasn’t looked back.

The latest incantation is Harmonicade, a dual-decked number arranged Wicki-Hayden style. Both decks have 5½ octaves, are (electrically) identical, and run off a single Teensy 3.6. We admire [KOOP]’s use of DB25 connectors to wrangle the wiring between the decks and the Teensy — quite a neat solution. Almost as neat as his beautifully-commented code.

Although the button decks and control boxes are all printed and open source, they are designed to be easily made from acrylic or plywood instead. [KOOP] is going to keep iterating until he’s totally happy with the control locations and layout, and the ease of breakdown and reassembly. We’ve got a double shot of videos for you after the break — one of [KOOP] playing Harmonicade, and a longer one exploring and playing its precursor, the Melodicade.

Tired of conventional-looking MIDI controllers? We hear your bellows and offer this MIDI controller in a concertina.

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Play That Funky 3D Printer…

January 19, 2020 by 16 Comments

Human brains are wired for music. Scientists think the oldest musical instruments were flutes that date back somewhere between 67,000 and 37,000 years ago. We assume though that people were banging on wood or their thighs, or knocking two rocks together long before that. Almost anything can be a musical instrument. A case in point: [elifer5000] walked into a room containing a lot of running 3D printers, and thought it seemed musical. Next thing you know, he harnessed 3D printers as a MIDI instrument.

At a hackathon, he found some software that converts a MIDI file to GCode. The only problem is a common printer has three axes and, therefore, can only produce (at most) three notes at once. The obvious answer to this problem is to use more printers, and that’s what he did, as you can see below.

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Fabric(ated) Drum Machine

January 7, 2020 by 3 Comments

Some folks bring out an heirloom table runner when they have company, but what if you sewed your own and made it musical? We’d never put it away! [kAi CHENG] has an Instructable about how to recreate his melodic material, and there is a link to his website, which describes his design process, not just the finished product. We have a video below showing a jam session where he exercises a basic function set.

GarageBand is his DAW of choice, which receives translated MIDI from a Lilypad. If you don’t have a Lilypad, any Arduino based on the ATmega328P chip should work seamlessly. Testing shows that conductive threads in the soft circuit results in an occasional short circuit, but copper tape makes a good conductor  at the intersections. Wide metallic strips make for tolerant landing pads beneath modular potentiometers fitted with inviting foam knobs. Each twist controls a loop in GarageBand, and there is a pressure-sensitive pad to change the soundset. Of course, since this is all over MIDI, you can customize to your heart’s content.

MIDI drums come in all shapes and sizes, from a familiar game controller to hand rakes.

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A STM32 Tonewheel Organ Without A Single Tonewheel

December 5, 2019 by 7 Comments

The one thing you might be surprised not to find in [Laurent]’s beautiful tonewheel organ build is any tonewheels at all.

Tonewheels were an early way to produce electronic organ sounds: by spinning a toothed wheel at different frequencies and transcending the signal one way or another it was possible to synthesize quite an array of sounds. We like to imagine that they’re all still there in [Laruent]’s organ, albeit very tiny, but the truth is that they’re being synthesized entirely on an STM32 micro controller.

The build itself is beautiful and extremely professional looking. We were unaware that it was possible to buy keybeds for a custom synthesizer, but a model from FATAR sits at the center of the show. There’s a MIDI encoder board and a Nucleo development board inside, tied together with a custom PCB. The UI is an momentary encoder wheel and a display from Mikroelektronika.

You can see and hear this beautiful instrument in the video after the break.

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Sara Adkins Is Jamming Out With Machines

December 4, 2019 by 1 Comment

Asking machines to make music by themselves is kind of a strange notion. They’re machines, after all. They don’t feel happy or hurt, and as far as we know, they don’t long for the affections of other machines. Humans like to think of music as being a strictly human thing, a passionate undertaking so nuanced and emotion-based that a machine could never begin to understand the feeling that goes into the process of making music, or even the simple enjoyment of it.

The idea of humans and machines having a jam session together is even stranger. But oddly enough, the principles of the jam session may be exactly what machines need to begin to understand musical expression. As Sara Adkins explains in her enlightening 2019 Hackaday Superconference talk, Creating with the Machine, humans and machines have a lot to learn from each other.

To a human musician, a machine’s speed and accuracy are enviable. So is its ability to make instant transitions between notes and chords. Humans are slow to learn these transitions and have to practice going back and forth repeatedly to build muscle memory. If the machine were capable, it would likely envy the human in terms of passionate performance and musical expression.

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World’s Smallest MIDI Synth, Now Even Better

October 28, 2019 by 6 Comments

We’re pretty sure there’s no internationally recognized arbiter of records like “World’s smallest full-featured polyphonic stereo MIDI synthesizer that fits in a DIN shell”. If there isn’t, there sure should be, and we’re pretty sure [mitxela]’s Flash-Synth would hold that particular record.

This is one of those lessons that some people just can’t leave a challenge alone. First [mitxela] built a MIDI synthesizer into a DIN connector, then a couple of months later he made a somewhat more streamlined version. While both were feats of engineering derring-do, neither was entirely satisfactory. With only square wave synthesis and a limit of eight voices, plus some unpleasant audio issues and a total lack of manufacturability, the next challenge was clear.

We won’t pretend to follow all the audio arcana, of which the video below and the build log have plenty, but the technical achievement is obvious enough. The Flash-Synth has an STM32, a tantalum SMD filter capacitor that dwarfs it, and a few support components on a flexible PCB that folds back on itself twice. This bit of circuit origami is connected to a 5-pin DIN plug and stuffed into the connector’s shell, which in turn mates to a custom-machined metal housing. A stereo audio jack lives at the other end of the assembly, and the whole synth is powered parasitically off the MIDI port.

The first half of the video below is mostly a demo that proves the synth sounds great and can do just about anything; skip to the 22-minute mark for the gory build details. Suffice it to say that [mitxela]’s past experience with ludicrous scale soldering served him well here.

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Turntable Spins Color And Sound Together

October 27, 2019 by 5 Comments

If you can’t grow your own synesthesia, buying electronics to do it for you is fine. Such is the case with the CHROMATIC by [Xavier Gazon], an artist who turns all kinds of electronics into circuit-bent musical art pieces. His project turns an old Philips Music 5120 turntable into a colorful MIDI sequencer, inspired by older 20th century instruments such as the Optophonic Piano and the Luminaphone.

The CHROMATIC uses colored pucks placed on a converted turntable to perform a looping sequence of chords in a given musical scale, generating MIDI data as output. Where its inspirations used primitive optics as their medium, this project employs a Teensy microcontroller and two modern optical sensors to do the work. One of these is a simple infrared sensor which tracks a white spot on the edge of the turntable, generating a MIDI clock signal to keep everything quantized and in sync. The other is a color sensor mounted on the tone arm, which can tell what color it sees and the height of the arm from the turntable.

While the instrument is still in beta testing phase details on how notes are generated aren’t yet given, though the general idea is that they are dictated by the color the tone arm sees and its position above the platter. Moving the tone arm changes which pucks it tracks, and the speed of the turntable can also be adjusted, changing how the melody sounds.​

The CHROMATIC is a very interesting project, but it’s not the first optical-based turntable hack we’ve seen here. We’ve also seen a much weirder use for a color sensor, too. Check out the video of this one in action after the break.

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