Homebrew Relay Computer Looks Like It Could Be A Commercial Product

January 19, 2021 by Dan Maloney 21 Comments

You may not have noticed, but we here at Hackaday really love our clicky stuff. Clicky mechanical keyboards, unnecessarily noisy flip-dot displays, and pretty much anything made with a lot of relays — they all grab our attention, in more ways than one. So it’s with no small surprise that we appear to have entirely missed perhaps the clickiest build of all: a fully operational 8-bit computer using nothing but relays.

What’s even more amazing about our failure to find and feature [Paul Law]’s excellent work is that he has been at it for the better part of a decade now. The first post on his very detailed and very well-crafted blog describing the build dates from 2013, when he was just testing LEDs in the arithmetic-logic unit (ALU). Since then, [Paul] has made incredible progress, building module after module, each containing a small portion of the computer’s functionality. The modules plug into card cages with backplanes to connect them, and the whole thing lives in an enclosure made from aluminum extrusion and glossy black panels for a truly sleek look. The computer is incredibly compact for something that uses 400+ DPDT relays to do its thinking.

In addition to the blog, [Paul] has a criminally undersubscribed YouTube channel with a quite recent series going over the computer in depth. We included the overall tour below, but you should really check out the rest of the videos to appreciate how much work went into this build. We’ve seen relay computers ranging in size from single-board to just plain ludicrous, but this one really takes the prize for fit and finish as well as functionality.

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Hardware Vs Software: Fight!

October 10, 2020 by Elliot Williams 41 Comments

It’s one of the great cliches in the hacker world: the hardware type and the software type. You can tell which of these two you are quite easily. When a project is actually 20% done, but you think it’s 90% done, and you say to yourself “And the rest is a simple matter of software”, you’re a hardware type. Ask anyone who has read my code, and they’ll tell you, I’m a hardware type.

Along with my blindness to the difficulties of getting the code right, I’ve also admittedly got an underappreciation of what powers lie in the dark typing arts. But I am not too proud to tip my hat when I see an awesome application of the soft stuff. Case in point: this Go board sequencer that we ran last week. An overhead webcam parses players’ moves as they put black and white stones down while playing the game of Go, and turns this into music.

The pure software type will be saying “but there’s a webcam and a Go board”. And indeed, that’s true. There are physical elements to this project that anchor it in the shared reality of the two people playing. But a hardware project this isn’t; it’s OpenCV and Max/MSP that make it work.

For comparison, look at the complexity of this similar physical sequencer. It’s got a 16 x 16 array of LEDs and switches and a CNC milled, primed, and painted surface that’s the size of a twin bed. Sawdust and hand-soldering: that’s a hardware project.

What I love about the Go sequencer is that it uses software just right. The piece is still physical. It could have just as easily been a VR world, where the two people would interact with each other only inside their goggles. But somehow that’s not quite as human as putting stones on a wooden board, sitting across from, and maybe even looking at, your opponent. The players aren’t forced to think about the software. They don’t feel like they’re playing a video game.

But at the same time, the software side of things makes all of the horrible hardware problems go away. Nobody is soldering a rat’s nest of 169 switches. There’s a webcam plugged into the USB port of a laptop. There’s a deep simplicity there.

Should you always trade out arcade buttons for OpenCV? Absolutely not! But is it worth considering the soft side when doing it in hardware is just too, well, hard? I’m open.

Mini Marble-Powered Synth Pays Homage To Its Bigger Cousins

August 22, 2020 by Dan Maloney 8 Comments

If imitation is the sincerest form of flattery, what then are we to make of something that shares only a few of the original’s design elements, operates in a completely different way, and has been scaled down to a fifth its size? Still seems like flattery to us.

Despite the changes, it’s clear where [Love Hultén] took inspiration for his miniature Marble Machine XS. Readers will no doubt see in it elements from [Martin Molin]’s original Marble Machine, the fantastic plywood and Lego musical contraption, along with his new Marble Machine X, the construction of which never seems to end. Like the originals, [Love]’s miniature version uses a lot of steel balls, albeit considerably scaled down, and it still uses a programming drum to determine where and when to drop them. But rather than strike real traditional instruments, the falling balls strike synthesizer keys, triggering a range of sounds through its built-in speaker. The whole thing is powered by a small electric motor rather than being hand-cranked and is small enough to sit on a desktop, a decided advantage over the mammoth machines to which it pays homage.

We have to say that as much as we love the hacksmanship of the original Marble Machine and the craftsmanship of its successor, the look and feel of [Love]’s machine just blows us away. We’re not sure what materials he used, but the whole hammertone paint scheme and Meccano look is a feast for nostalgic eyes.

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Sequence Your Beats With The Magic Of Magnets

February 15, 2020 by Lewin Day 10 Comments

Typically, when we think of a music sequencer, we envisage LEDs and boards covered in buttons. Of course, there are naturally other ways to build such a device. MesoTune takes a different tack entirely, relying on magnets and rotating mechanisms to get the job done.

MesoTune acts as a MIDI controller, and is designed to be hooked up to a computer or other MIDI synthesizer device. The heart of MesoTune is a set of eight magnet wheels, rotating together on a common shaft. The rotational speed of the shaft, dictated by the requested tempo in beats per minute, is controlled by an Arduino. Each magnet wheel has 16 slots into which the user can place a spherical magnet. Every time a magnet on the wheel passes a hall sensor, it sends a MIDI message to the attached computer which is then responsible for using this to synthesize the relevant sound.

There are other useful features, too. Each of the eight magnet wheels, or channels, gets its own fader, which can be used to control volume or other parameters. There’s also a handy tempo display, and a 16-button touchpad for triggering other events. These additions make it more practical to use in a compositional context, where it’s nice to have extra controls to make changes on the fly.

Made out of 3D printed parts and readily available off the shelf components, it’s a fun alternative sequencer design that we’re sure many makers could whip up in just a weekend. We’d love to see other remixes of the design – if you’ve got one, hit us up at the tipline. We’ve seen other great sequencer builds before, too. Video after the break.

Never Mind The Sheet Music, Here’s Spreadsheet Music

February 2, 2019 by Sven Gregori 7 Comments

Nothing says Rockstar Musician Lifestyle like spreadsheet software. Okay, we might have mixed up the word order a bit in that sentence, but there’s always Python to add some truth to it. After all, if we look at the basic concept of MIDI sequencers, we essentially have a row of time-interval steps, and depending on the user interface, either virtual or actual columns of pitches or individual instruments. From a purely technical point of view, spreadsheets and the like would do just fine here.

Amused by that idea, [Maxime] wrote a Python sequencer that processes CSV files that works with both hardware and software MIDI synthesizers. Being Python, most of the details are implemented in external modules, which makes the code rather compact and easy to follow, considering it supports both drums and melody tracks in the most common scales. If you want to give it a try, all you need is the python-rtmidi and mido module, and you should be good to go.

However, if spreadsheets aren’t your thing, [Maxime] has also a browser-based sequencer project with integrated synthesizer ongoing, with a previous version of it also available on GitHub. And in case software simply doesn’t work out for you here, and you prefer a more hands-on experience, don’t worry, MIDI sequencers seem like an unfailing resource for inspiration — whether they’re built into an ancient cash register, are made entirely out of wood, or are built from just everything.

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Turning LEGO Blocks Into Music With OpenCV

December 30, 2018 by Donald Papp 2 Comments

We’re not sure what it is, but something about LEGO and music go together like milk and cookies when it comes to DIY musical projects. [Paul Wallace]’s Lego Music project is a sequencer that uses the colorful plastic pieces to build and control sound, but there’s a twist. The blocks aren’t snapped onto anything; the system is entirely visual. A computer running OpenCV uses a webcam to watch the arrangement of blocks, and overlays them onto a virtual grid where the positions of the pieces are used as inputs for the sequencer. The Y axis represents pitch, and the X axis represents time.

Embedded below are two videos. The first demonstrates how the music changes based on which blocks are placed, and where. The second is a view from the software’s perspective, and shows how the vision system processes the video by picking out the colored blocks, then using their positions to change different values which has an effect on the composition as a whole.

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With Grinning Keyboard And Sleek Design, This Synth Shows It All

October 28, 2018 by Donald Papp 24 Comments

Stylish! is a wearable music synthesizer that combines slick design with stylus based operation to yield a giant trucker-style belt buckle that can pump out electronic tunes. With a PCB keyboard and LED-surrounded inset speaker that resembles an eyeball over a wide grin, Stylish! certainly has a unique look to it. Other synthesizer designs may have more functions, but certainly not more style.

The unit’s stylus and PCB key interface resemble a Stylophone, but [Tim Trzepacz] has added many sound synthesis features as well as a smooth design and LED feedback, all tied together with battery power and integrated speaker and headphone outputs. It may have been originally conceived as a belt buckle, but Stylish! certainly could give conference badge designs a run for their money.

The photo shown is a render, but a prototype is underway using a milled PCB and 3D printed case. [Tim]’s Google photo gallery has some good in-progress pictures showing the prototyping process along with some testing, and his GitHub repository holds all the design files, should anyone want a closer look under the hood. Stylish! was one of the twenty finalists selected for the Musical Instrument Challenge portion of the 2018 Hackaday Prize and is therefore one of the many projects in the running for the grand prize!