A Parts Bin MIDI Controller In 24 Hours

October 20, 2024 by Bryan Cockfield 9 Comments

Part of the reason MIDI has hung on as a standard in the musical world for so long is that it is incredibly versatile. Sure, standard instruments like pianos and drums can be interfaced with a computer fairly easily using this standard, but essentially anything can be converted to a MIDI instrument with the right wiring and a little bit of coding. [Jeremy] needed to build a MIDI controller in a single day, and with just a few off-the-shelf parts he was able to piece together a musical instrument from his parts bin.

The build is housed in an off-brand protective case from a favorite American discount tool store, but the more unique part of the project is the choice to use arcade buttons as the instrument’s inputs. [Jeremy] tied eight of these buttons to an Arduino Uno to provide a full octave’s worth of notes, and before you jump to the comments to explain that there are 12 notes in an octave, he also added a button to the side of the case to bend any note when pressed simultaneously. An emergency stop button serves as a master on/off switch and a MIDI dongle on the other side serves as the interface point to a computer.

After a slight bit of debugging, the interface is up and running within [Jeremy]’s required 24-hour window. He’s eventually planning to use it to control a custom MIDI-enabled drum kit, but for now it was fun to play around with it in some other ways. He’s also posted the project code on a GitHub page. And, if this looks a bit familiar, this was not [Jeremy]’s first MIDI project. He was also the creator of one of the smallest MIDI interfaces we’ve ever seen.

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Digital Audio Workstation In A Box

September 23, 2024 by Bryan Cockfield 4 Comments

Although it’s still possible to grab a couple of friends, guitars, and a set of drums and start making analog music like it’s 1992 and there are vacant garages everywhere yearning for the sounds of power chords, the music scene almost demands the use of a computer now. There are a lot of benefits, largely that it dramatically lowers the barrier to entry since it greatly reduces the need for expensive analog instruments. It’s possible to get by with an impressively small computer and only a handful of other components too, as [BAussems] demonstrates with this tiny digital audio workstation (DAW).

The DAW is housed inside a small wooden box and is centered around a Behringer JT-4000 which does most of the heavy lifting in this project. It’s a synthesizer designed to be as small as possible, but [BAussems] has a few other things to add to this build to round out its musical capabilities. A digital reverb effects pedal was disassembled to reduce size and added to the DAW beneath the synthesizer. At its most basic level this DAW can be used with nothing but these components and a pair of headphones, but it’s also possible to add a smartphone to act as a sequencer and a stereo as well.

For a portable on-the-go rig, this digital audio workstation checks a lot of the boxes needed including MIDI and integration with a computer. It’s excellent inspiration for anyone else who needs a setup like this but doesn’t have access, space, or funds for a more traditional laptop- or desktop-centered version. For some other small on-the-go musical instruments we recently saw a MIDI-enabled keyboard not much larger than a credit card.

Doing MIDI With Discrete Logic Is Neat, If Not Particularly Useful

September 13, 2024 by Lewin Day 4 Comments

MIDI is normally baked into the chipset of a synthesizer, or something you use a microcontroller to handle. But that’s not the only way to speak the language! [Kevin] decided to have some fun doing MIDI with discrete logic instead, with some pretty neat results.

[Kevin] had previously built a control voltage step sequencer called the Baby8, which relied on 4017 counter ICs. He later realized he could repurpose three of his old Baby8 PCBs to create something that could generate MIDI using nothing more than discrete logic. The stack of three boards generate a simple MIDI message—in this case, a two-byte Program Change command. At 8 bits per byte, plus a start and stop bit, that comes out to 20 bits in total. The bits to be sent are configured via the switches on the PCBs, and clocked out through the counter ICs via a clock running at the MIDI baud rate of 31,250 Hz.

Obviously, it’s not very practical to code your MIDI commands manually via DIP switches and then clock them out in this fashion. But—it does work, and you can do it! If you wanted to build an old-school logic circuit that just spits out simple short MIDI commands, this is one way to go about it.

We’ve seen [Kevin]’s work before, too, like this neat musical rotary phone build.

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Get More Freedom With This Guitar Pedal

August 19, 2024 by Bryan Cockfield 13 Comments

When the electric guitar was first produced in the 1930s, there was some skepticism among musicians as to whether or not this instrument would have lasting impact or be a flash-in-the-pan novelty. Since this was more than a decade before the invention of the transistor, it would have been hard then to imagine the possibilities that a musician nowadays would have with modern technology to shape the sound of an instrument like this. People are still innovating in this space as well as new technology appears, like [Gary Rigg] who has added a few extra degrees of freedom to a guitar effects pedal.

A traditional expression pedal, like a wah-wah pedal, uses a single motion to change an aspect of the sound of the guitar, and is generally controlled with the musician’s foot. [Gary]’s pedal, on the other hand, can be manipulated in three different ways to control separate elements of the instrument’s sound. It can be pitched forward and back like a normal effects pedal, but also rolled side-to-side and twisted around its yaw axis. The pedal has a built-in IMU to measure the various position changes of the pedal, which is then translated by an RP2040 microcontroller to a MIDI signal which controls the three different aspects of the sound digitally.

While the yaw motion might be difficult for a guitarist to create with their foot while playing, the idea for this pedal is still excellent. Adding in a few more degrees of freedom gives the musician more immediate control over the sound of their instrument and opens up ways of playing that might not be possible or easy with multiple pedals, with the MIDI allowing for versatility that might not be available in many analog effects pedals. Not every pedal needs MIDI though; with the help of a Teensy this digital guitar pedal has all its effects built into a self-contained package.

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AI Image Generator Twists In Response To MIDI Dials, In Real-time

July 30, 2024 by Donald Papp 29 Comments

MIDI isn’t just about music, as [Johannes Stelzer] shows by using dials to adjust AI-generated imagery in real-time. The results are wild, with an interactivity to them that we don’t normally see in such things.

[Johannes] uses Stable Diffusion‘s SDXL Turbo to create a baseline image of “photo of a red brick house, blue sky”. The hardware dials act as manual controls for applying different embeddings to this baseline, such as “coral”, “moss”, “fire”, “ice”, “sand”, “rusty steel” and “cookie”.

By adjusting the dials, those embeddings are applied to the base image in varying strengths. The results are generated on the fly and are pretty neat to see, especially since there is no appreciable amount of processing time required.

The MIDI controller is integrated with the help of lunar_tools, a software toolkit on GitHub to facilitate creating interactive exhibits. As for the image end of things, we’ve previously covered how AI image generators work.

The Last Instrument To Get Auto-Tuned

July 30, 2024 by Bryan Cockfield 14 Comments

Various decades have their musical signature, like the excessive use of synthesizers and hairspray in the 1980s pop music scene. Likewise, the early 2010s was marked by a fairly extreme use of autotune, a technology that allows sounds, especially vocals, to be shifted to precise pitches regardless of the pitch of the original source. In this dark era, a wide swath of instruments and voices on the charts were auto-tuned at some point, although we don’t remember this iconic instrument ever being featured among the annals of pitch-shifted pop music.

The auto-tuned kazoo created by [Guy Dupont] does its pitch corrections on-the-fly thanks to a built-in ESP-32-S3 microcontroller which, through a microphone inside the kazoo, listens for note of the musician’s hum and corrects it to the closest correctly pitched note. Once it identifies the note it outputs a kazoo-like pitch-corrected note from a small speaker, also hidden inside the instrument. It does this fast enough for live performances using the YIN fundamental frequency estimation algorithm. Not only can the kazoo be played directly, but thanks to the implementation of MIDI it can be used to control other synthesizers or be played through other means as a stand-alone synthesizer.

Much like the 80s, where the use of synthesizers relaxed from excessive use on nearly every instrument on every track throughout the decade to a more restrained use as the decade faded, so has autotune been toned down in most music to be more subtly applied. But like our enjoyment of heavily synthesized tunes outside the 80s like those by Daft Punk or The Weeknd, we can also appreciate something heavily auto-tuned outside of the 2010s like a stylized kazoo or a T-Pain-style guitar effects pedal.

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MIDI Controller In A Cubic Inch

July 27, 2024 by Bryan Cockfield 2 Comments

MIDI as a standard has opened up a huge world to any musician willing to use a computer to generate or enhance their playing and recording. Since the 80s, it has it has revolutionized the way music is produced and performed, allowing for seamless integration of digital instruments, automation of complex sequences, and unprecedented control over everything from production to editing. It has also resulted in a number of musical instruments that probably wouldn’t be possible without electronic help, like this MIDI instrument which might be the world’s smallest.

Fitting into a cubic inch of space, the tiny instrument’s volume is mostly taken up by the MIDI connector itself which was perhaps an acceptable size by 1980s standards but seems rather bulky today. A two-layer PCB split into three sections sandwiches the connector in place and boasts an ATtiny85 microcontroller and all the associated electronics needed to implement MIDI. Small threaded screws hold the platform together and provide each layer with a common ground. Four small pushbuttons at the top of the device act as the instrument’s keys.

The project’s creator (and Hackaday alum!) [Jeremy Cook] has it set up to play notes from a piano right now, but has also made the source code available so that any musical action can be programmed onto these buttons. Flexibility is perhaps MIDI’s greatest strength and why the standard has lasted for decades now, as it makes it fairly straightforward to build more comprehensive, easy-to-learn musical instruments or even musical instruments out of retro video game systems.

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