A picture of a life sized magikarp from pokemon

Magic Magikarp Makes Moves

December 5, 2025 by Ian Bos 6 Comments

One of the most influential inventions of the 20th century was Big Mouth Billy Bass. A celebrity bigger than the biggest politicians or richest movie stars, there’s almost nothing that could beat Billy. That is, until [Kiara] from Kiara’s Workshop built a Magikarp version of Big Mouth Billy Bass.

Sizing in at over 2 entire feet, the orange k-carp is able to dance, it is able to sing, and it is able to stun the crowd. Magikarp functions the same way as its predecessor; a small button underneath allows the show to commence. Of course, this did not come without its challenges.

Starting the project was easy, just a model found online and some Blender fun to create a basic mold. Dissecting Big Mouth Billy Bass gave direct inspiration for how to construct the new idol in terms of servos and joints. Programming wasn’t even all that much with the use of Bottango for animations. Filling the mold with the silicone filling proved to be a bit more of a challenge.

After multiple attempts with some minor variations in procedure, [Kirara] got the fish star’s skin just right. All it took was a paint job and some foam filling to get the final touches. While this wasn’t the most mechanically challenging animatronic project, we have seen our fair share of more advanced mechanics. For example, check out this animatronic that sees through its own eyes!

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Musical Motors, BLDC Edition

September 12, 2025 by Tyler August 21 Comments

This should count as a hack: making music from a thing that should not sing. In this case, [SIROJU] is tickling the ivories with a Brushless DC motor, or BLDC.

To listen to a performance, jump to 6:27 in the embedded video. This BLDC has a distinctly chip-tune like sound, not entirely unlike other projects that make music with stepper motors. Unlike most stepper-based instruments we’ve seen [SIROJU]’s BLDC isn’t turning as it sings. He’s just got it vibrating by manipulating the space vector modulation that drives the motor — he gets a response of about 10 kHz that way. Not CD-quality, no, but plenty for electronic music. He can even play chords of up to 7 notes at a time.

There’s no obvious reason he couldn’t embed the music into a proper motor-drive signal, and thus allow a drone to hum it’s own theme song as it hovers along. He’s certainly got the chops for it; if you haven’t seen [SIROJU]’s videos on BLDC drivers on YouTube, you should check out his channel. He’s got a lot of deep content about running these ubiquitous motors. Sure, we could have just linked to him showing you how to do FOC on an STM32, but “making it sing” is an expression for mastery in English, and a lot more fun besides.

There are other ways to make music with motors. If you know of any others, don’t hesitate to send us a tip.

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A black PCB is shown, with an Arduino Nano mounted in the bottom left corner. The rest of the space on the PCB is used up by ten DIP integrated circuits and a few resistors and diodes. Several black and red wires connect different parts of the PCB.

Meowsic Keyboard MIDI Adapter Aims For Purrfection

June 14, 2025 by Aaron Beckendorf 3 Comments

Both small children and cats have a certain tendency to make loud noises at inopportune times, but what if there were a way to combine these auditory effects? This seems to have been the reasoning behind the creation of the Meowsic keyboard, a children’s keyboard that renders notes as cats’ meows. [Steve Gilissen], an appreciator of unusual electronic instruments, discovered that while there had been projects that turned the Meowsic keyboard into a MIDI output device, no one had yet added MIDI input to it, which of course spurred the creation of his Meowsic MIDI adapter.

The switches in the keys of the original keyboard form a matrix of rows and columns, so that creating a connection between a particular row and column plays a certain note. [Steve]’s plan was to have a microcontroller read MIDI input, then connect the appropriate row and column to play the desired note. The first step was to use a small length of wire to connect rows and columns, thus manually mapping connections to notes. After this tedious step, he designed a PCB that hosts an Arduino Nano to accept input, two MCP23017 GPIO expanders to give it enough outputs, and CD4066BE CMOS switches to trigger the connections.
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Pi Pico Throws Us For A (MIDI) Loop

April 28, 2025 by Tyler August 3 Comments

Modern micro-controllers are absolute marvels, but it isn’t too many projects use one and nothing else. For an example of such simplicity, take a look at [oyama]’s Pi Pico MIDI looper.

It uses the PicoW to interface with a synth via MIDI-BLE, which can be anything from pro equipment to an app on your smartphone. The single control button is already provided by the Pico W– the bootsel button is wearing a lot of hats here, allowing one to select betwixt 4 tracks (all different drums), set the tempo, and input notes on the selected track.

The action is simple: pound out the rhythm for each track, and it will repeat forever, or at least until you press the single button again to change it. There’s also a nice serial interface so you can see what’s going on via UART or USB. For what it does, it is amazingly simple: the BOM is one item, the Pi Pico W. To see it in action, check out the demo video below.

Given the ADC chops on the Pico, it would probably be easy to extend this build with a speaker to make a tiny stand-alone, one-button synth. Or you could add more buttons buttons, but then it’s no longer the beautifully simple single-line BOM project that [oyama] showed us.

Of course, everything is open-source on GitHub, under the BSD license, and forking is encouraged, so [oyama] would doubtless be more than happy to see you go nuts hacking and extending this tiny MIDI looper.

We’ve actually seen the MIDI-BLE standard used before, like this hack adding it to a Eurorack. If you like synths, you may be interested to see what it takes to design one from scratch, sans microcontroller. Continue reading “Pi Pico Throws Us For A (MIDI) Loop” →

75-In-One Music

October 23, 2024 by Jenny List 18 Comments

It’s likely that many Hackaday readers will have had their interest in electronics as a child honed by exposure to an electronics kit. The type of toy that featured a console covered in electronic components with spring terminals, and on which a variety of projects could be built by wiring up circuits. [Matthew North Music] has a couple of these, and he’s made a video investigating whether they can be used to make music.

The kits he’s found are a Radio Shack one from we’re guessing the 1970s, and a “Cambridge University Recording Studio” kit that looks to be 1990s-vintage. The former is all discrete components and passive, while the latter sports that digital audio record/playback chip that was the thing to have in a novelty item three decades ago. With them both he can create a variety of oscillator and filter circuits, though for the video he settles for a fairly simple tone whose pitch is controlled by an light-dependent resistor, and a metronome as a drum beat.

The result is a little avant garde, but certainly shows promise. The beauty of these kits is they can now be had for a song, and as grown-ups we don’t have to follow the rules set out in the book, so we can see there’s a lot of fun to be had. We look forward to some brave soul using them in a life performance at a hacker camp. Continue reading “75-In-One Music” →

The Luminiferous Theremin

August 9, 2024 by Al Williams 5 Comments

[Extreme Kits] asks the question: “What the hell is a luminiferous theremin?” We have to admit, we know what a thermin is, but that’s as far as we got. You’ve surely seen and heard a theremin, the musical instrument developed by Leon Theremin that makes swoopy music often associated with science fiction movies. The luminiferous variation is a similar instrument that uses modern time of flight sensors to pick up your hand positions.

The traditional instrument uses coils, and your hands alter the frequency of oscillators. Some versions use light sensors to avoid the problems associated with coils. While the time of flight sensors also use light, they are immune to many false readings caused by stray light.

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ESP32 Powered Crunch-E Makes Beats On The Go

June 11, 2024 by Tom Nardi 8 Comments

There’s no shortage of devices out there for creating electronic music, but if you’re just looking to get started, the prices on things like synthesizers and drum machines could be enough to give you second thoughts on the whole idea. But if you’ve got a well stocked parts bin, there’s a good chance you’ve already got most of what you need to build your own Crunch-E.

Described by creator [Roman Revzin] as a “keychain form factor music-making platform”, the Crunch-E combines an ESP32, an MAX98357 I2S audio amplifier, an array of tactile buttons, and a sprinkling of LEDs and passives. It can be built on a perfboard using off-the-shelf modules, or you can spin up a PCB if you want something a bit more professional. It sounds like there’s eventually going to be an option to purchase a pre-built Crunch-E at some point as well.

But ultimately, the hardware seems to be somewhat freeform — the implementation isn’t so important as long as you’ve got the major components and can get the provided software running on it.

The software, which [Roman] is calling CrunchOS, currently provides four tracks, ten synth instruments, and two drum machine banks. Everything can be accessed from a 4 x 4 button array, and there’s a “cheat sheet” in the documentation that shows what each key does in the default configuration. Judging by the demo video below, it’s already an impressively capable platform. But this is just the beginning. If everything goes according to plan and more folks start jamming on their own Crunch-E hardware, it’s not hard to imagine how the software side can be expanded and adapted over time.

Over the years we’ve seen plenty of homebrew projects for producing electronic music, but the low-cost, simple construction, and instant gratification nature of the Crunch-E strikes us as a particularly compelling combination. We’re eager to see where things develop from here.

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