Musical Hacks

1455 Articles

PendulumSynth Ties Music And Physics Together

February 17, 2022 by 2 Comments

Many musicians will be familiar with the metronome, a pendulum charged with generating a rhythmic tick to keep one’s performance in regular time. With PendulumSynth, [mrezanvari] takes the same basic pendulum but uses it in an altogether different musical way.

The build relies on a 10-inch plastic ball to serve as the weighted end of the pendulum, stuffed with a STM32F411CE BlackPill board, a BNO085 IMU, and an nRF radio module for sending out data for external processing. The pendulum’s motion is turned into MIDI data or CV for output to musical hardware which handles actually generating the output sounds.

The system operates in a variety of modes. Gravity mode outputs continuous MIDI data and CV relative to the continuous motion of the pendulum, while DIV3 mode tracks the pendulum’s motion and outputs 3 regular trigger points that correspond as such.

The combination of the intuitive physical nature of the pendulum and its sheer large size makes for an enticing musical exhibit. We’ve seen some other great musical installation pieces before, too. Video after the break.

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Sending MIDI Wirelessly With The NRF24L01

February 17, 2022 by 6 Comments

MIDI is a standard known by musicians and instruments all over the world. The basic twist on regular serial has helped studios around the world to work more efficiently. [Kevin] wanted to try sending MIDI data wirelessly, but rather than the typical Bluetooth solution, decided to use the humble nRF24L01 instead.

The circuitry used is simple: [Kevin] simply wired up two Arduino Unos with nRF24L01 radio modules, which communicate over SPI. Alternatively, an even quicker solution is to use a Keywish Arduino RF Nano, which packs a nRF24L01 on board. One Arduino can then be hooked up to a MIDI OUT port on an instrument, and it will send out MIDI signals wirelessly. The second Arduino can then be plugged into a MIDI IN port and repeat out what it receives over the air.

The real work was in the firmware, which takes MIDI data and packages it in a suitable form to send out over the nRF24L01. The system can operate in a one-to-one mode, emulating a single MIDI cable, or a multicast mode, where one sender transmits information to many receivers.

It’s a neat hack and one we could imagine would be useful in some fun performance situations. We’ve seen others do work on wireless MIDI interfaces for Eurorack hardware, too. Video after the break.

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You Can Send MIDI Over I2C If You Really Need To

February 15, 2022 by 11 Comments

The Musical Instrument Digital Interface has a great acronym that is both nice to say and cleanly descriptive. The standard for talking to musical instruments relies on a serial signal at 31250 bps, which makes it easy to transmit using any old microcontroller UART with a settable baud rate. However, [Kevin] has dived into explore the utility of sending MIDI signals over I2C instead.

With a bit of hacking at the Arduino MIDI library, [Kevin] was able to get the microcontroller outputting MIDI data over the I2C interface, and developed a useful generic I2C MIDI transport for the platform. His first tests involved using this technique in concert with Gravity dual UART modules. After he successfully got one running, [Kevin] realised that four could be hooked up to a single Arduino, giving it 8 serial UARTS, or, in another way of thinking, 8 MIDI outputs.

At its greatest level of development, [Kevin] shows off his I2C MIDI chops by getting a single Raspberry Pi Pico delivering MIDI signals to 8 Arduinos, all over I2C. All the Arduinos are daisy-chained with their 5V and I2C lines wired together, and the system basically swaps out traditional MIDI channels for I2C addresses instead.

There’s not a whole lot of obvious killer applications for this, but if you want to send MIDI data to a bunch of microcontrollers, you might find it easier daisy-chaining I2C rather than hopping around with a serial line in the classic MIDI-IN/MIDI-THRU fashion.

We’ve seen [Kevin]’s work before too, like the wonderful Lo-Fi Orchestra. Video after the break.

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A computer program written in basic next to a modular synthesizer with many switches and lights

Modular Synth Pairs Perfectly With The Apple II

February 4, 2022 by 4 Comments

We have a soft spot for synthesizers – seriously, who doesn’t? So when [Joshua Coleman] combined his retro-looking DIY modular synth with the equally retro Apple II computer, we just had to share it with you.

The two machines are paired using a vintage digital-to-analog logic controller pack. This DAC was originally used to control model trains using your Apple II – something that we now desperately need to see in action. The pack can output voltages between 0 and 2.55 V at 8-bit resolution (or 256 steps), which is plenty for a retro synth.

With the card installed in Slot 7 of the Apple II and the DAC wired through to the synth’s CV/gate, it’s then a trivial matter of writing POKE statements in Applesoft BASIC to control the synth. The video after the break demonstrates playing a simple melody, as well as how one might use the Apple II keyboard to ‘play’ the synth in real time.

If you’re interested in building your own, the video below has all the information needed, as well as helpful advice on where to find a DAC for your preferred model of vintage computer. If all that doesn’t tickle your musical fancy, make sure to check out our coverage on the Game Boy MIDI synth, or perhaps this peculiar synth and visualizer combo.

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Custom Piano Tickles The Ivories

January 28, 2022 by 6 Comments

The core ethos of “hacking” is usually interpreted as modifying something for a use that it wasn’t originally built for. Plenty of builds are modifications or improvements on existing technology, but sometimes that just isn’t enough. Sometimes we have to go all the way down and build something completely from scratch, and [Balthasar]’s recent piano-like musical instrument fits squarely into this category.

This electronic keyboard is completely designed and built from scratch, including the structure of the instrument and the keys themselves. [Balthasar] made each one by hand out of wood and then built an action mechanism for them to register presses. While they don’t detect velocity or pressure, the instrument is capable of defining the waveform and envelope for any note, is able to play multiple notes per key, and is able to change individual octaves. This is thanks to a custom 6×12 matrix connected to a STM32 microcontroller. Part of the reason [Balthasar] chose this microcontroller is that it can do some of the calculations needed to produce music in a single clock cycle, which is an impressive and under-reported feature for the platform.

With everything built and wired together, the keyboard is shockingly versatile. With the custom matrix it is easy to switch individual octaves on the piano to any range programmable, making the 61-key piano capable of sounding like a full 88-key piano. Any sound can be programmed in as well, further increasing its versatility, which is all the more impressive for being built from the ground up. While this build focuses more on the electronics of a keyboard, we have seen other builds which replicate the physical action of a traditional acoustic piano as well.

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A wooden xylophone with electronic contraptions for robotic playback

Robotic Xylophone Makes Music With MIDI Magic

January 27, 2022 by 8 Comments

The MIDI format has long been used to create some banging electronic music, so it’s refreshing to see how [John P. Miller] applied the standard in his decidedly analog self-playing robotic xylophone.

Framed inside a fetching Red Oak enclosure, the 25-key instrument uses individual solenoids for each key, meaning that it has no problem striking multiple bars simultaneously. This extra fidelity really helps in reproducing the familiar melodies via the MIDI format. The tracks themselves can be loaded onto the device via SD card, and selected for playback with character LCD and rotary knob.

The software transposes the full MIDI music spectrum of a particular track into a 25-note version compatible with the xylophone. Considering that a piano typically has 88 keys, some musical concessions are needed to produce a recognizable playback, but overall it’s an enjoyable musical experience.

Perhaps most remarkable about this project is the documentation. If you want to build your own, everything you need to know is available online, and the no-solder approach makes this project very accessible. Most of the write-up happened some years ago, and we’re really interested to see what improvements have been made since.

The robotic xylophone is reminiscent of these automatic tubular bells from some time ago. These musical hacks can be particularly inspiring, and we can’t wait to see more.

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Young Maker Mixes Traditional Japanese Construction With Modern Art

January 25, 2022 by 4 Comments

We’re Makers. By definition, we make things. Some of us prefer to build from scraps, while others like to make their own IC’s in their garage. [Make With Miles] on the other hand prefers one of the oldest types of making around: woodworking. And in this build, he goes a step further by using a very old Japanese method of woodworking called Kumiko to build a Stratocaster style electric guitar. The results are absolutely stunning as you can see in the video below.

Inspired by a challenge put forth by [The Modern Maker Podcast] to build a woodworking project that ties into another hobby that isn’t related to woodworking, [Miles] knocked it out of the park by including several art forms in this one-off Strat.

The centerpiece of this guitar build is the Kumiko style of construction used within the body. Kumiko is a Japanese method of assembling wood without the use of fasteners. Developed around 600-700AD, Kumiko is as much a construction method as an art form. [Miles] went further by filling the Kumiko framework with blackened epoxy resin which was then sanded and polished. Decals bring the headstock into the motif, but the attention to details goes much, much further. Be sure to watch the video so you can get an appreciation for the high level of workmanship that this young man displays.

That’s right- [Miles] isn’t a maker with decades of experience. In fact in 2017, one of his YouTube videos was “12 yr Old Builds a Row Boat!!!” [Miles], our hats are off to you and we look forward to seeing your art progress, for you truly have commanded the attention of the maker community that you are so rightfully part of.

Just as [Miles]’ guitar hides some great hacks, so does this guitar with Hot Swappable pickups. Thanks to [Keith] for sending this on to the Tip Line!

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