Delta Bot Plucks Out Tunes on a Mandolin

November 16, 2018 by Dan Maloney 22 Comments

Is there no occupation safe from the scourge of robotic replacement? First it was the automobile assemblers, then fast food workers, and now it’s the — mandolin players?

Probably not, unless [Clayton Darwin]’s mandolin playing pluck-bot has anything to say about it. The pick-wielding delta-ish robot can be seen in action in the video below, plucking out the iconic opening measures of that 70s prom-theme favorite, “Colour My World.” The robot consists of two stepper motors connected to a hinged wooden arm by two pushrods. We had to slow the video down to catch the motion, but it looks like [Clayton] has worked out the kinematics so that the pick can be positioned in front of any of the mandolin’s eight strings. A quick move of the lower stepper then flicks the pick across a string and plucks it. [Clayton] goes into some detail about how he built the motion-control part in an earlier video; he also proves that steppers are better musicians than we’ll ever be with a little “Axel F” break.

It’s only a beginning, of course, but the complexity of the kinematics just goes to show how simple playing an instrument isn’t. Unless, of course, you unleash an endless waterfall of marbles on the problem.

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Rock Out to the Written Word with BookSound

November 14, 2018 by Tom Nardi 15 Comments

With his latest project, [Roni Bandini] has simultaneously given the world a new type of audiobook and music. Traditional audiobooks are basically the adult equivalent of having somebody read you a bedtime story, but BookSound actually turns the written word into electronic music. You won’t be able to boast to your friends that as a matter of fact, you have read that popular new novel, but at least you might be able to dance to it.

[Roni] says he’s still working on perfecting the word to music mapping, so the results shown in the video after the break are still a bit rough. But even in these early stages there’s no denying this is an exceptionally unique project, and we’re excited to see where it goes from here.

Inside the classy looking 3D printed enclosure is a Raspberry Pi, an OLED display, and the button and switch which make up the extent of the device’s controls. At the end of the arm is a standard Raspberry Pi Camera module, which gives the BookSound a bird’s eye view of the book to be songified.

To turn your favorite book into electronic beats, simply open it up, put it under the gaze of BookSound, and press the button on the front. Because the Raspberry Pi isn’t exactly a powerhouse, it takes about two minutes for it to scan the page, perform optical character recognition (OCR), and compose the track before you start to hear anything.

If you’re wondering what the secret sauce is to turn words into music, [Roni] isn’t ready to share his source code just yet. But he was able to give us a few high-level explanations of what’s going on inside BookSound. For example, to generate the song’s BPM, the software will count how many words per paragraph are on the page: so a book with shorter paragraphs will consequently have a faster tempo to match the speed at which the author is moving through ideas. Similarly, drum kicks are generated based on the number of syllables in each paragraph. In the future, he’s looking at adding “lyrics” by running commonly used words on the page through a text to speech engine and inserting them into the beat.

We’ve seen practical applications of OCR on the Raspberry Pi in the past and even similar looking book scanning arrangements. But nothing quite like BookSound before, which at this point, is really saying something.

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A $4 Ultrasonic Theremin Looks Cheesy on Purpose

November 10, 2018 by Al Williams 5 Comments

We don’t think [bleepbit] will take offense when we say the “poor man’s theremin” looks cheesy — after all, it was built in a cheese container. Actually, it isn’t a bad case for a simple device, as you can see in the picture and the video below. Unlike a traditional theremin, the device uses ultrasonics to detect how far away your hand is and modifies the sound based on that.

There are also two buttons — one to turn the sound off and another to cycle through some effects. We liked how it looked like a retro cassette, though. The device uses a cheap Arduino clone, but even with a real Arduino, the price wouldn’t be too bad. However, the price tag quoted doesn’t include a few connectors or the speaker that appears in the schematic. There’s a note that the model built uses a jack instead of a speaker, but it would be nice to include both and use the kind of jack that disconnects the speaker when you plug speakers or headphones in.

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Quick and Dirty MIDI Interface with USBASP

November 4, 2018 by Tom Nardi 10 Comments

[Robson Couto] recently found himself in need of MIDI interface for a project he was working on, but didn’t want to buy one just to use it once; we’ve all been there. Being the creative fellow that he is, he decided to come up with something that not only used the parts he had on-hand but could be completed in one afternoon. Truly a hacker after our own hearts.

Searching around online, he found documentation for using an ATtiny microcontroller as a MIDI interface using V-USB. He figured it shouldn’t be too difficult to adapt that project to run on one of the many USBASP programmers he had laying around, and got to work updating the code.

Originally written for the ATtiny2313, [Robson] first had to change around the pin configuration so it would work on the ATmega8 in the USBASP, and also updated the USB-V implementation to the latest version. With the code updated, he programmed one of the USBASP adapters with a second one by connecting them together and putting a jumper on the J2 header.

He had the software sorted, but there was still a bit of hardware work to do. To provide isolation for the MIDI device, he put together a small circuit utilizing a 6N137 optoisolator and a couple of passive components on a piece of perf board. It’s not pretty, but it does fit right into the programming connector on the USBASP. He could have fired up his PCB CNC but thought it was a bit overkill for such a simple board.

[Robson] notes that he hasn’t implemented MIDI output with his adapter, but that the code and the chip are perfectly capable of it if you need it for your project. Finding the schematic to hook up to the programmer’s TX pin is left as an exercise for the reader.

If you don’t have a USBASP in the parts bin, we’ve seen a very similar trick done with an Arduino clone in the past.

Redesigning the Musical Keyboard with Light-Up Buttons

November 4, 2018 by Brian Benchoff 13 Comments

A piano’s keyboard doesn’t make sense. If you want to want to play an F major chord, just hit an F, an A, and a C — all white keys, all in a row. If you want to play a B major chord, you hit B, a D#, and an F#. One white key, then two black ones. The piano keyboard is not isomorphic, meaning chords of the same quality have different shapes. For their entry into the Hackaday Prize, [CSCircuits] and their crew are working on a keyboard that makes chords intuitive. It’s called the Kord Kontroller, and it’s a device that would also look good hooked up to Ableton.

The layout of the Kord Kontroller puts all the scale degrees arranged in the circle of fifths in the top of the keyboard. To play 90% of western music, you’ll hit one button for a I chord, move one button to the left for a IV chord, and two buttons to the right for a V chord. Chord quality is determined by the bottom of the keyboard, with buttons for flat thirds, fourths, ninths, elevenths and fourteenths replacing or augmenting notes in the chords you want to play. Since this is effectively a MIDI controller, there are buttons to change octaves and modes.

As far as hardware goes, this keyboard is constructed out of Adafruit Trellis modules that are a 4×4 grid of silicone buttons and LEDs that can be connected together and put on a single I2C bus. The enclosure wraps these buttons up into a single 3D printed grid of button holes, and with a bit of work and hot glue, everything looks as it should.

It’s an interesting musical device, and was named as a finalist in the Musical Instrument Challenge. You can check out a demo video with a jam sesh below.

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Launchpad MIDI Controller Put to Work with Python

November 4, 2018 by Tom Nardi 7 Comments

For Hackaday readers who might not spend their free time spinning electronic beats at raves, the Launchpad by Novation is a popular peripheral for creating digital music with tools such as Ableton Live. It’s 8×8 grid of RGB LED backlit buttons are used to trigger different beats and clips by sending MIDI commands to the computer over USB. While not a strict requirement for performing digital music, it also helps that it looks like you’re flying a spaceship when using it.

It’s definitely a slick piece of gear, but the limited stock functionality means you’re unlikely to see one outside of the Beat Laboratory. Though that might change soon thanks to LPHK, created by [Ella Jameson]. She’s created a program in Python that allows you to use the Novation Launchpad as a general purpose input device. But rather than taking the easy way out by just turning the hardware into a USB HID device or something along those lines, LPHK implements an impressive set of features including its own internal scripting language.

In the video after the break, [Ella] walks us through some basic use cases, such as launching programs or controlling the system volume with individual buttons. LPKH has a GUI which provides a virtual representation of the Launchpad, and allows configuring each button’s color and function as well as saving and loading complete layouts.

For more advanced functionality, LPHK utilizes a scripting language that was inspired by the Hak5 USB Rubber Ducky. Scripts are written with plain English commands and very simple syntax, meaning you don’t need to have any programming experience to create your own functions. There’s also a script scheduling system with visual feedback right on the board: if a button is pulsing red it means it has a script waiting for its turn to execute. When the key is rapidly flashing the script is actively running. A second tap of the button will either remove it from the queue or kill the running script, depending on what the status was when you hit it.

[Ella] makes it clear this software is still a work in progress; it’s not as polished as she’d like and still has bugs, but it’s definitely functional for anyone who’s looking to wring a bit more functionality out of their $150 Launchpad. She’s actively looking for beta testers and feedback, so if you’ve already got one of these boards give it a shot and let her know what you think.

In the past we’ve seen hackers fiddling with the open source API Novation released for their Launchpad controllers, but overall there hasn’t been a lot of work done with these devices. Perhaps that will soon change with powerful software like this in development.

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Analog Synth, But In Cello Form

November 3, 2018 by Brian Benchoff 8 Comments

For one reason or another, electronic synthesizing musical instruments are mostly based around the keyboard. Sure, you’ve got the theremin and other oddities, but VCAs and VCFs are mostly the domain of keyboard-style instruments, and have been for decades. That’s a shame, because the user interface of an instrument has a great deal to do with the repertoire of that instrument. Case in point: [jaromir]’s entry for the Hackaday Prize. It’s an electronic analog synth, in cello form. There’s no reason something like this couldn’t have been built in the 60s, and we’re shocked it wasn’t.

Instead of an electrified cello with a piezo on the bridge or some sort of magnetic pickup, this cello is a purely electronic instrument. The fingerboard is metal, and the strings are made of kanthal wire, the same wire that goes into wire-wound resistors. As a note is fingered, the length of the string is ‘measured’ as a value of resistance and used to control an oscillator. Yes, it’s weird, but we’re wondering why we haven’t seen anything like this before.

How does this cello sound? Remarkably like a cello. [jaromir] admits there are a few problems with the build — the fingerboard is too wide, and the fingerboard should probably be curved. That’s really an issue with the cellist, not the instrument itself, though. Seeing as how [jaromir] has never even held a cello, we’re calling this one a success. You can check out a video of this instrument playing Cello Suite No. 1 below. It actually does sound good, and there’s a lot of promise here.

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