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Archive for the ‘Midi’ Category

Apparently not content with a traditional laser harp, Jonathan Bumstead set out to take things in a different direction. What he came up with is a device whose laser strings are arranged horizontally, and loop though its boxy structure for an amazing audiovisual effect. 

The aptly named Upright Laser Harp is divided up into six rows, which each contain two laser/photoresistor pairs for an instrument total of 12 notes. Each laser is reflected once before hitting its photoresistor to wrap the entire structure in light, and values are sensed by an Arduino Mega as note inputs. Sounds are then generated by an Adafruit Music Maker Shield, and different MIDI instruments are selected with a rotary switch and a stepper-based electromechanical display system. 

Laser harps are musical devices with laser beam “strings.” When the beam is blocked, a note is played by the instrument. Usually laser harps have the beams travel vertically in the shape of a fan or vertical lines. 

In this project, I built a laser harp with stacked laser beams that propagate horizontally. The beams reflect off mirrors to form square shaped beam paths. Instead of a MIDI output like my previous laser harp, this device has built-in MIDI player so the output is an audio signal. This means the device does not have to be connected to a computer or MIDI player (e.g. keyboard) to play sound. Both built-in speakers and audio output jack are available for playing music.

Be sure to check out the mini-concert and build details in the video below!

[Julien] is one of those cool dads who shows his love with time invested rather than money spent. His daughter plays the harp, and you would not believe the price of concert harps. Even the cheap ones are several thousand USD. So naturally, he decided he would build her a MIDI concert harp from the ground up.

This plucky work in progress uses a strain gauge and an AD620 amplifier on every string to detect the tension when plucked. These amplifiers are connected to Arduinos, with an Arduino every nine strings. The Arduinos send MIDI events via USB to a Raspberry Pi, which is running the open synth platform Zynthian along with Pianoteq.

The harp is strung with guitar strings painted with silver, because he wanted capacitive touch support as well. But he scrapped that plan due to speed and reliability issues. Strain past the break to check out a brief demo video.

[Julien] used strings because he wanted to anchor the harpist in tactility. But you’re right; many if not most MIDI harps use lasers.

Upon obtaining a small toy piano, Måns Jonasson went to work “Arduinoizing” it with 30 solenoids to hammer out tunes. 

A MIDI shield is used to pipe commands from a computer to the Arduino Mega that’s used for control, and after experimenting with discreet wiring and electronics for each of the solenoids, he switched to motor shields as outlined here to simplify the setup. This, along with a new version of the solenoid holders he designed, cleaned up the build nicely, allowing it to play a plinky version of the Super Mario Bros. theme song.

Be sure to check out the Mario themed auto-concert in the video below, plus a video outline of its construction, below. 

Toy pianos are fun to plink around on for a minute, but their small keyboards and even smaller sound make them musically uninteresting pretty quickly. [Måns Jonasson] found a way to jazz up a two-octave toy piano almost beyond recognition. All it took was thirty solenoids, a few Arduinos, a MIDI shield, and a lot of time and patience.

This particular piano’s keys use lever action to strike thin steel tines. These tines are spaced just wide enough for tiny 5V solenoids to fit over them. Once [Måns] got a single solenoid striking away via MIDI input, he began designing 3D printed holders to affix them to the soundboard.

Everything worked with all thirty solenoids in place, but the wiring was a bird’s nest of spaghetti until he upgraded to motor driver shields. Then he designed a new bracket to hold eight solenoids at once, with a channel for each pair of wires. Every eight solenoids, there’s an Arduino and a motor shield.

The resulting junior player piano sounds like someone playing wind chimes like a xylophone, or a tiny Caribbean steel drum. Check out the build video after the break.

Hate the sound of toy pianos, but dig the convenient form factor? Turn one into a synth.

Michael Koopman wanted to learn piano. However, after finding this pursuit frustrating, he instead decided to assemble his own 3D-printed MIDI jammer keyboard, inspired by the AXiS-49 interface pad. 

His instrument is controlled via an Arduino Due, with 85 buttons arranged in a diagonal pattern. This allows for whole steps on the horizontal axis, fourths on one diagonal, fifths on the other diagonal, and octaves on the vertical axis. 

This configuration enables the device to be used in a variety of ways, and features an additional six buttons and four potentiometers to vary playing style, along with ¼ inch jacks for auxiliary inputs. 

As seen in the video below, while Koopman had a hard time with the piano, apparently that wasn’t case with his MIDI keyboard, as he’s able to play it beautifully—even using two at a time around 8:15!

Keytars may have had their moment of popularity in the 1980s, but instruments of the day can’t hold a candle to “The Blade” by makers Sam Wray, Siddharth Vadgama, and Greig Stewart. 

The musical device feeds signals from a pair of Guitar Hero necks, along with a stripped down keytar from Rock Band, into an Arduino Mega. This data is then sent to a Raspberry Pi running PD Extended, and is used to control a pair of Game Boys to produce distinct 8-bit sounds. Audio output can be further modified with a Leap Motion sensor embedded in one of the two necks. 

What makes up The Blade?

– 3D-printed housing

We custom modeled and printed a housing for the instrument to ensure it would be ergonomic to wield, hold together with all the components, and also look badass.

– Two Guitar Hero necks

The necks, hacked off a couple of old Guitar Hero controllers, were totally rewired to output the button presses to jumper cables.

– Arduino Mega

All the wiring from the Guitar Hero necks fed into the Mega, which then registered the button presses and output appropriate MIDI signals over USB serial into the Raspberry Pi.

– Rock Band keytar

We stripped this down to the bare keyboard and had the MIDI also going into the Pi.

Raspberry Pi

Taking in all the MIDI, and running PD Extended we got this to manage and re-map all the button presses we needed. This then output to a MIDI thru box.

– Arduino Boy

This fed the MIDI signals from the thru box into the Game Boy.

Game Boy

These were heart. With MIDI fed in from a multitude of sources, the Game Boy, running mGB, was the synthesizing the signals into sound, output via a standard 3.5mm jack. 

Leap Motion
The Leap Motion was used for further sound modulation.

When you see a vacuum cleaner, most people see a useful implement to keep their carpets clean. James Bruton, however, envisioned another use—as a musical instrument. His new project, which made its appearance this year on April Fools’ Day, sucks air through 12 recorders, allowing it to play a full octave and the melody and lead from “Africa” by Toto… or so he’d have you believe!

In reality, power for his instrument comes from a separate Henry Hoover in another room, blowing air through the normally-suction tube of the broken device on the screen. An Arduino Mega, along with a MIDI shield, enables it to open and close air lines to each of the 12 recorders as needed. 

Check out how it was made in the first video below and the original fake in the second.


Engineers create something out of nothing, and no where is this more apparent than in the creation of customized computer hardware. To make a simple MIDI controller, you need knowledge of firmware design and computer architecture, you need knowledge of mechanical design, and you need to know electronic design. And then you need the actual working knowledge and experience to wield a tool, be it a hammer, laser cutter, or an IDE. [Mega Das] brought together all of these skill to build a MIDI controller. Sure, it’s for bleeps and bloops coming out of a speaker, but take a step back and realize just how awesome it is that any one person could imagine, then implement such a device.

The electronics for this build include a printed circuit board that serves to break out the connections on an Arduino nano to a dozen arcade push buttons, four slide pots, two rotary pots, and a handful of screw terminals to connect everything together. Mechanically, this is a laser-cut box engraved with some fancy graphics and sized perfectly to put everything inside.

Yes, we’ve seen a lot of MIDI controllers built around the Arduino over the years, but this one is in a class by itself. This is taking off-the-shelf parts and customizing them to exactly what you want, and a prodigious example of what is possible with DIY hardware creation. You can check out the build video below.

Michael Sobolak was inspired by the hardware dedicated to Ableton digital audio software, along with the DIY MIDI Fighter pads that others have constructed, to make his own light-up version

His device is cut out of ¼-inch MDF, housing a 4×4 array of main buttons, 18 smaller buttons on the bottom and eight potentiometers, four of which are surrounded by NeoPixel rings.

To handle this massive array of inputs, he turned to the use of multiplexers, creating a spaghetti-like—though functional—wiring arrangement hidden underneath. The pad uses an Arduino Uno to control the NeoPixels, while a separate board is tasked with the MIDI interface. 

You can see Sobolak’s project crank out music in the video below, with LEDs that react to potentiometer input settings.

If you’ve ever seen a MIDI pad with dozens of light-up buttons producing electronic music, you may have considered building one using an Arduino. As shown in GreatScott!’s latest write-up, you can indeed create your own Novation Launchpad-like device using a Nano for control, but the real question is should you?

In the video below, GreatScott! shares how made a 6×6 pad, using a 3D-printed body and buttons arranged in a matrix to save I/O, along with WS2812B LEDs. He also goes over the MIDI protocol, which he was able to implement using loopMIDI and Hairless MIDI to serial bridge for Arduino interface. 

While the DIY option may or may not be right for you, the concepts presented could be applied to a wide range of electronic musical interface projects.

In this episode of DIY or Buy I will be showing you how I created my own Launchpad. That means I will show you how I combined a design idea with 3D prints, WS2812 LEDs, tactile switches and an Arduino to create a proper MIDI instrument. While building I will also tell you a bit about a keyboard matrix and in the end determine what advantages the DIY Launchpad offers. 



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