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Archive for the ‘musical hacks’ Category

As soon as [pashiran] laid eyes on his first hand-cranked music box, he knew he was in love. Then, he started punching the holes for his first ditty. As the repetitive stress of punching heated up his arm, his love cooled a bit. Annealed by the ups and downs of this experience, he decided to design a machine that can punch the holes automatically.

Soon, [pashiran] found his people — a community of music boxers that transform MIDI files to DXF format, which creates coordinates for CAD software. In [pashiran]’s music puncher, an Arduino MEGA takes a DXF file and bubble-sorts the jumble of x-coordinates. The MEGA conducts a trio of two stepper motors and DC motor. One stepper pushes the paper through on the x-axis, and the other moves the puncher head back and forth across the paper scroll as the y-axis. The DC motor moves the punch up and down.

Now, paired with [Martin] of [Wintergatan]’s method for chaining music box paper together, [pashiran] can write a prog-rock-length opus without fear of repetitive stress injury. And since he’s published the STL and INO files, now you can, too. Watch it punch and play 250 notes worth of “See My Vest” “Be Our Guest” after the break.

There’s more than one way to avoid manually punching all those holes. When [Wintergatan] was wrestling this problem, he inspired the hacker community to create a MIDI-to-laser-cut-stencil solution.

What can you do with ferromagnetic PLA? [TheMixedSignal] used it to give new meaning to the term ‘musicians’ gear’. He’s made a proof of concept for a DIY tone generator, which is the same revolutionary system that made the Hammond organ sing.

Whereas the Hammond has one tonewheel per note, this project uses an Arduino to drive a stepper at varying speeds to produce different notes. Like we said, it’s a proof of concept. [TheMixedSignal] is proving that tonewheels can be printed, pickups can be wound at home, and together they will produce audible frequencies. The principle is otherwise the same — the protruding teeth of the gear induce changes in the magnetic field of the pickup.

[TheMixedSignal] fully intends to expand on this project by adding more tone wheels, trying different gear profiles, and replacing the stepper with a brushless motor. We can’t wait to hear him play “Karn Evil 9”. In the meantime, put on those cans and check out the demo/build video after the break.

We don’t have to tell you how great Hammond organs are for making music. But did you know they can also encode secret messages?

Via the Arduino blog.

Fans of MaKey MaKey may find this project similar, but there’s a lot more to the Mini Automat than making music from fruit.

The idea for the Mini Automat (which is an off-shoot of the original Automat project by [Dada Machines]) is to make music accessible to anyone. The device functions as a plug and play MIDI-controller that connects to a computer, MIDI workstation (keyboards and sequencers), or DAW for input and triggers actuators on the output to create music.

The modifications make the originally Automat more hackable by making the board compatible with Arduino and Circuit Python, as well as adding in digital and analog pins for connecting to sensors, buttons, or light systems.

The team has released all schematics, firmware, and software, with only the board layouts unreleased to the public. From solenoids that push, pull, jiggle, smash, and bash at drums to surfaces that vibrate screws and beads, there’s a huge variety of household objects that can be used to make complex layered musical compositions, even for a one-person musician.


The Berlin-based team works on open source music tech hardware with the hopes of bringing environmentally and financially sustainable ideas to market.

One of our favorite things about the rise of hobbyist development ecosystems such as the Arduino is that it’s now possible to make a MIDI controller out of almost anything, as long as you have the the shields and the dedication. We’re glad that [James Bruton] takes the occasional break from making robots to detour into instrument making, because his latest creation turns it up to 11.

This awesome guitar uses a barcode scanner to play notes, and various arcade controls to manipulate those notes. The barcodes themselves scan as ASCII values, and their equivalent integers are sent to an external MIDI device. This futuristic axe is built on an Arduino Mega, with a USB shield for the barcode scanner, and a MIDI shield on top that [James] connects to various synths in the video after the break.

In between shooting barcodes, the right hand also controls octave shifting and changing MIDI channels with the joystick, and doing pitch-bends with the rotary encoder. The array of arcade buttons on the bottom neck let him switch between single player for monophonic synths, and multiplayer for polys. The other three buttons are press-and-scan programmable single-note sounders that assist in chord-making and noodling.

We particularly dig the construction, which is a combination of 20/20 and 3D printed boxes. [James] found some angled PVC to serve as fretboards for the four necks, and a nice backgrounds for bar codes.The only thing we would change is the native beep of the barcode scanner — either silence it forever or make it mutable, because it doesn’t jive with every note. It might be nice to get the gun to scan continuously so [James] doesn’t get trigger finger. Or better yet, build the scanner into a glove.

Want to do something more useful with that barcode scanner in your parts bin? Use it to manage your household inventory. But first, reacquaint yourself with the history of the humble barcode as presented by [Adam Fabio].

Thanks for the tip, [baldpower]!

Over the summer [ElectroSmash] put the finishing touches on the Arduino Audio Meter, a shield for the Arduino Uno that visualizes various aspects of an incoming audio signal on a set of four 8×8 LED dot matrices. Obsentisibly it’s for use on a guitar pedalboard, but thanks to the incredible documentation and collection of example code provided by the team, the project promises to be an excellent platform for all sorts of audio experimentation.

Incoming audio is amplified with an MCP6002 and fed into the Uno’s Analog to Digital Converter, where it’s processed via whatever Sketch the user has uploaded. User input is provided by a digital encoder with push-button. A set of four MAX7219 chips control the entire 256-pixel matrix with just three pins on the Arduino. The resolution of the display allows the Arduino Audio Meter to show more than just a simple VU meter, it can even do text and basic graphics.

[ElectroSmash] provides various Sketches for use with the Arduino Audio Meter that provide the expected repertoire of audio visualizations, but they also provide a number of interesting Sketches to expand the capabilities of the device in unexpected ways. Some of them could be useful for a stage musician, such a tool to tune your guitar, whereas others are fun uses of the hardware such as a game of “Snake”.

With the entire project released as open source, users are free to run wild with the Arduino Audio Meter. Writing your own custom software is an obvious first step to making the project your own, but adding additional hardware features and functions certainly aren’t out of the question either.

Our very own [Lewin Day] once walked us through the effort involved in building boutique guitar pedals, and while the Audio Audio Meter’s capabilities are somewhat limited as it doesn’t have the ability to change the audio going through it, we’re still interested in seeing what the community will come up with once they have an easy way to bring their ideas to life.

[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.

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.

We don’t think [bleepbit] will take offense when we say the “poor man’s theremin” looks cheesy — after all, it was built in a cheese container. Actually, it isn’t a bad case for a simple device, as you can see in the picture and the video below. Unlike a traditional theremin, the device uses ultrasonics to detect how far away your hand is and modifies the sound based on that.

There are also two buttons — one to turn the sound off and another to cycle through some effects. We liked how it looked like a retro cassette, though. The device uses a cheap Arduino clone, but even with a real Arduino, the price wouldn’t be too bad. However, the price tag quoted doesn’t include a few connectors or the speaker that appears in the schematic. There’s a note that the model built uses a jack instead of a speaker, but it would be nice to include both and use the kind of jack that disconnects the speaker when you plug speakers or headphones in.

The code is simple and there are four possible effects you can cycle through with one of the buttons. Unlike a real theremin, you can trigger this one with anything the ultrasonic sensor can see. The Arduino audio quality is not superb, of course, but it is still a fun rainy day project.

We couldn’t help but think that a 32-bit Arduino could have used one of the sophisticated audio libraries. However, there are other libraries that might improve things even with the 8-bit processor.

Granted, this isn’t a true theremin, but we’ve seen plenty of those, too. We’ve even used the same sensors to control a PC.

It’s common knowledge that tapping a wine glass produces a pitch which can be altered by adjusting the level of the tipple of choice inside. By filling twelve glasses with different amounts of liquid and tuning them to the twelve notes of the scale, it’s possible to make a one-octave instrument – though the speed and polyphony are bottle-necked by the human operator. If you think it sounds like a ripe project for automation, you’re correct: [Bitluni’s lab] has done what needed to be done, and created a MIDI instrument which plays the glasses using mallets.

Electronically it’s a simple build – some 12 V solenoids driven by MOSFETs, with an Arduino in charge. For the mechanical build, a 3D printer proved very useful, as each mallet could be made identical, ensuring a consistent tone across all glasses. Rubber covers printed in flexible filament were fitted to reduce the overtones and produce a clearer sound. [Bitluni] also utilised different types of glasses for the low and high pitches, which also helped to improve the clarity of the tone.

MIDI is of course the perfect protocol for this application; simple, lightweight and incredibly widely used, it’s the hacker’s delight for projects like this. The instrument can perform pre-programmed sequences, or be played live with a MIDI controller. Both of these are shown in the video after the break – stick around for a unique rendition of Flight Of The Bumblebee. For a more compact wine glass based music creation solution, we recommend this nifty project, which alters pitch using a water balloon raised and lowered into the glass by a servo. 

Effects pedals: for some an object of overwhelming addiction, but for many, an opportunity to hack. Anyone who plays guitar (or buys presents for someone who does) knows of the infinite choice of pedals available. There are so many pedals because nailing the tone you hear in your head is an addictive quest, an itch that must be scratched. Rising to meet this challenge are a generation of programmable pedals that can tweak effects in clever ways.

With this in mind, [ElectroSmash] are back at it with another open source offering: the pedalSHIELD MEGA. Aimed at musicians and hackers who want to learn more about audio, DSP and programming, this is an open-hardware/open-software shield for the Arduino MEGA which transforms it into an effects pedal.

The hardware consists of an analog input stage which amplifies and filters the incoming signal before passing it to the Arduino, as well as an output stage which does the DAC-ing from the Arduino’s PWM outputs, and some more filtering/amplifying. Two 8-bit PWM outputs are used simultaneously to make pseudo 16-bit resolution — a technique you can read more about in their handy forum guide.

The list of effects currently implemented covers all the basics you’d expect, and provides a good starting point for writing custom effects. Perhaps a library for some of the commonly used config/operations would be useful? Naturally, there are some computational constraints when using an Arduino for DSP, though it’s up to you whether this is a frustrating fact, or an opportunity to write some nicely optimised code.

[ElectroSmash] don’t just do pedals either: here’s their open source guitar amp.

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