midi

389 Articles

Companion MIDI Pedal Helps Roland Groovebox Along

January 30, 2026 by 1 Comment

The Roland SP-404 Mk2 is a popular groovebox that can deliver a great beat if you know how to use it. If you’re seeking greater control than is available out of the box, though, you might like to try a custom pedal built by [Romain Dereu].

The concept is simple enough—[Romain] whipped up a bespoke MIDI device to specifically control various features of the SP-404. It’s based on an Arduino Nano, though it could also be built with an Arduino Uno if so desired. The microcontroller sends the requisite MIDI messages out via its serial UART. The microcontroller is built into a pedal-style enclosure with a big toggle switch and a foot switch. This enables the triggering of various pads on the SP-404, with modes selected via the toggle.

It’s a simple build that opens up new possibilities when playing with the SP-404. If you’ve ever wanted a custom device to spit out some specific MIDI commands to control the synths or drum machines in your performance rig, this project is a great example of how easy this is to achieve. Meanwhile, if you’re whipping your own custom MIDI gear at home, we always love to see it land on our tipsline!

Wireless MIDI Controller Has Lots Of Knobs

January 24, 2026 by 8 Comments

We live in a golden age for MIDI controllers. [rheslip]’s contribution to the milieu is a twisty take on the format, in that it’s covered in an array of knobs. Thus the name—Twisty 2. 

The controller can be built using the Raspberry Pi Pico or Pico 2. It’s set up to read a 4×4 array of clickable encoders, plus two bonus control knobs to make 18 in total, which are read via a 74HC4067 analog mux chip. There’s also an SK6812 RGB LED for each encoder, and an OLED display for showing status information. MIDI output is via USB, or, if you purchased the W variant of the Pi Pico/Pico 2, it can operate wirelessly over Bluetooth MIDI instead. The controller is set up to send MIDI CC messages, program changes, or note on/off messages depending on its configuration. Flipping through different modes is handled with the bottom set of encoders and the OLED display.

Few musicians we’ve ever met have told us they learned how to play the encoders, and yet. The cool thing about building your own MIDI controller is you can tune it to suit whatever method of performance strikes your fancy. If the name of this build alone has you inspired, you could always whip up a MIDI controller out of a Twister mat.

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DIY Synth Takes Inspiration From Fretted Instruments

December 11, 2025 by 7 Comments

There are a million and one MIDI controllers and synths on the market, but sometimes it’s just more satisfying to make your own. [Turi Scandurra] very much went his own way when he put together his Diapasonix instrument.

Right away, the build is somewhat reminiscent of a stringed instrument, what with its buttons laid out in four “strings” of six “frets” each. Only, they’re not so much buttons, as individual sections of a capacitive touch controller. A Raspberry Pi Pico 2 is responsible for reading the 24 pads, with the aid of two MPR121 capacitive touch ICs.

The Diapasonix can be played as an instrument in its own right, using the AMY synthesis engine. This provides a huge range of patches from the Juno 6 and DX7 synthesizers of old. Onboard effects like delay and reverb can be used to alter the sound. Alternatively, it can be used as a MIDI controller, feeding its data to a PC attached over USB. It can be played in multiple modes, with either direct note triggers or with a “strumming” method instead.

We’ve featured a great many MIDI controllers over the years, from the artistic to the compact. Video after the break. Continue reading “DIY Synth Takes Inspiration From Fretted Instruments” →

A Touchscreen MIDI Controller For The DIY Set

December 7, 2025 by 8 Comments

MIDI controllers are easy to come by these days. Many modern keyboards have USB functionality in this regard, and there are all kinds of pads and gadgets that will spit out MIDI, too. But you might also like to build your own, like this touchscreen design from [Nick Culbertson].

The build takes advantage of a device colloquially called the Cheap Yellow Display. It consists of a 320 x 240 TFT touchscreen combined with a built-in ESP32-WROOM-32, available under the part number ESP32-2432S028R.

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The synth in question in its acrylic case.

DIY Polyphonic Synth Sings In 8-Part Harmony

November 22, 2025 by 9 Comments

There’s just something about an analog synthesizer. You’d think that for electronic music, digital sampling would have totally taken over by now, but that’s really not true. The world of analog synths is alive and well, and [Polykit] has a new, open-source polyphonic synthesizer to add to the ever-growing chorus of electronic instruments.

The analog part is thanks to the eight identical voice cards that plug into the machine’s mainboard: each one has a voltage controlled oscillator to generate tones, an envelope generator, multiple voltage-controlled amplifiers, and even a pole mixing filter which is also, yes, voltage controlled. Each voice card outputs stereo, and yes, there are controllable mixing circuits for left and right output.

All that voltage control means a lot of lines from digital-to-analog converters (DACs), because while this is an analog synth, it does have a MIDI interface, and that means that a microcontroller needs to be able to speak voltage. In this case, the brains are an ATmega2560. Instead of stacking the board with enough expensive DACs to interpret the MCU’s digital signals, [Polykit] is instead is using some clever tricks to get more work out of the one DAC he has. Some things get tied together on all eight voices, like the envelope parameters; other values are run through a demultiplexer to make the most possible use of the analog lines available. Of course that necessitates some latching circuitry to hold the demuxed values on those lines, but it’s still cheaper than multiple high-quality DACs.

It’s a well-thought out bit of kit, down to the control panel and acrylic case, and the writeup is worth reading to get the full picture. The voice cards, main board and control board all have their own GitHub repositories you can find at the bottom of the main page. If you’re into video, [Polykit] has a whole series on this project you might want to check out on Makertube; we’ve embedded the first one below.

If you want to get your toes wet in the wonderful world of synthesizers, this library of seventy synths is an amazing place to start, because it has great simple projects.

Thanks to [Polykit] for the tip!

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A Childhood Dream, Created And Open Sourced

October 7, 2025 by 12 Comments

Some kids dream about getting a pony, others dream about a small form factor violin-style MIDI controller. [Brady Y. Lin] was one of the latter, and now, with the skills he’s learning at Northwestern, he can make that dream a reality — and share it with all of us as an open source hardware project.

The dream instrument’s name is Stradex1, and it’s a lovely bit of kit. The “fretless” neck is a SoftPot linear potentiometer being sampled by an ADS1115 ADC — that’s a 16-bit unit, so while one might pedantically argue that there are discreet frets, there’s 2^15 of them, which is functionally the same as none at all. Certainly it’s enough resolution for continuous-sounding pitch control, as well as vibrato, as you can see at 3:20 in the demo video below. The four buttons that correspond to the four strings of a violin aren’t just push-buttons, but also contain force sensors (again, sampled by the 16-bit ADC) to allow for fine volume control of each tone.

A few other potentiometers flesh out the build, allowing control over different MIDI parameters, such as what key [Brady] is playing on. The body is a combination of 3D printed plastic and laser-cut acrylic, but [Brady] suggests you could also print the front and back panels if you don’t happen to have a laser cutter handy.

This project sounds great, and it satisfies the maker’s inner child, so what’s not to love. We’ve had lots of MIDI controllers on Hackaday over the years — everything from stringless guitars  to wheel-less Hurdy-Gurdies to say nothing of laser harps galore — but somehow, we’ve never had a MIDI violin. The violin hacks we have featured tend to be either 3D printed or comically small.

If you like this project but don’t feel like fabbing and populating the PCB, [Brady] is going to be giving one away to his 1000th YouTube subscriber. As of this writing, he’s only got 800, so that could be you!

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Rediscovering Microsoft’s Oddball Music Generator From The 1990s

August 14, 2025 by 8 Comments

There has been a huge proliferation in AI music creation tools of late, and a corresponding uptick in the number of AI artists appearing on streaming services. Well before the modern neural network revolution, though, there was an earlier tool in this same vein. [harke] tells us all about Microsoft Music Producer 1.0, a forgotten relic from the 1990s.

The software wasn’t ever marketed openly. Instead, it was a part of Microsoft Visual InterDev, a web development package from 1997. It allowed the user to select a style, a personality, and a band to play the song, along with details like key, tempo, and the “shape” of the composition. It would then go ahead and algorithmically generate the music using MIDI instruments and in-built synthesized sounds.

As [harke] demonstrates, there are a huge amounts of genres to choose from. Pick one, and you’ll most likely find it sounds nothing like the contemporary genre it’s supposed to be recreating. The more gamey genres, though, like “Adventure” or “Chase” actually sound pretty okay. The moods are hilariously specific, too — you can have a “noble” song, or a “striving” or “serious” one. [harke] also demonstrates building a full song with the “7AM Illusion” preset, exporting the MIDI, and then adding her own instruments and vocals in a DAW to fill it out. The result is what you’d expect from a composition relying on the Microsoft GS Wavetable synth.

Microsoft might not have cornered the generative music market in the 1990s, but generative AI is making huge waves in the industry today.

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