Don’t Fret Over The Ukulele

March 27, 2021 by Bryan Cockfield 17 Comments

A ukulele is a great instrument to pick to learn to play music. It’s easy to hold, has a smaller number of strings than a guitar, is fretted unlike a violin, isn’t particularly expensive, and everything sounds happier when played on one. It’s not without its limited downsides, though. Like any stringed instrument some amount of muscle memory is needed to play it fluidly which can take time to develop, but for new musicians there’s a handy new 3D printed part that can make even this aspect of learning the ukulele easier too.

Called the Easy Fret, the tool clamps on to the neck of the ukulele and hosts a series of 3D printed “keys” that allow for complex chord shapes to be played with a single finger. In this configuration the chords C, F, G, and A minor can be played (although C probably shouldn’t be considered “complex” on a ukulele). It also makes extensive use of compliant mechanisms. For example, the beams that hit the chords use geometry to imitate a four-bar linkage. This improves the quality of the sound because the strings are pressed head-on rather than at an angle.

While this project is great for a beginner learning to play this instrument and figure out the theory behind it, its creator [Ryan Hammons] also hopes that it can be used by those with motor disabilities to be able to learn to play an instrument as well. And, if you have the 3D printer required to build this but don’t have an actual ukulele, with some strings and tuning pegs you can 3D print a working ukulele as well.

MIDI All The Things Hack Chat

March 22, 2021 by Dan Maloney 5 Comments

Join us on Wednesday, March 24 at noon Pacific for the MIDI All the Things Hack Chat with Tim Alex Jacobs!

In our technologically complex world, standards are a double-edged sword. While they clearly make it possible for widgets and doodads to interoperate with each other, they also tend to drift away from their original intention over time, thanks to the march of progress or even market forces. If there’s one thing you can expect about standards, it’s that they beget other standards.

One standard that has stood the test of time, with modification of course, is the Musical Instrument Digital Interface, or MIDI. It’s hard to overstate the impact MIDI has had on the music world since it was first dreamed up in the early 1980s. Started amid a Wild West of competing proprietary synchronization standards, MIDI quickly became the de facto interface for connecting electronic musical instruments together. And as it did, it moved from strictly pro-grade equipment down the market to prosumer and home users, fueled in part by the PC revolution.

Tim Alex Jacobs, who is perhaps better known as Mitxela on his YouTube channel, has long been interested in applying MIDI to unusual corners of the musical world. We’ve seen him MIDI-fy things that barely qualify as musical instruments, and also build a polyphonic synthesizer so small it fits within the shell of the DIN connector that’s so strongly associated with the MIDI standard. Tim joins us on the Hack Chat this week to talk about his experiences with MIDI, and to help us understand all the ways we can work with the interface in our builds.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, March 24 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
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Guitar Effects With No (Unwanted) Delay

March 15, 2021 by Bryan Cockfield 23 Comments

MIDI has been a great tool for musicians and artists since its invention in the 1980s. It allows a standard way to interface musical instruments to computers for easy recording, editing, and production of music. It does have a few weaknesses though, namely that without some specialized equipment the latency of the signals through the various connected devices can easily get too high to be useful in live performances. It’s not an impossible problem to surmount with the right equipment, as illustrated by [Philip Karlsson Gisslow].

The low-latency MIDI interface that he created is built around a Raspberry Pi Pico. It runs a custom library created by [Philip] called MiGiC which specifically built as a MIDI to Guitar interface. The entire setup consists of a preamp to boost the guitar’s signal up to 3.3V where it is then fed to the Pi. This is where the MIDI sampling is done. From there it sends the information to a PC which is able to play the sound back quickly with no noticeable delay.

[Philip] also had to do a lot of extra work to port the software to the Pi which lacks a lot of the features of its original intended hardware on a Mac or Windows machine, and the results are impressive, especially at the end of the video where he uses the interface to play a drum machine via his guitar. And, while MIDI is certainly a powerful application for a guitarist, we have also seen the Pi put to other uses in this musical realm as well.

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Peek Into This Synth’s Great Design (And Abandoned Features)

March 9, 2021 by Donald Papp 30 Comments

[Tommy]’s POLY555 is an analog, 20-note polyphonic synthesizer that makes heavy use of 3D printing and shows off some clever design. The POLY555, as well as [Tommy]’s earlier synth designs, are based around the 555 timer. But one 555 is one oscillator, which means only one note can be played at a time. To make the POLY555 polyphonic, [Tommy] took things to their logical extreme and simply added multiple 555s, expanding the capabilities while keeping the classic 555 synth heritage.

The real gem here is [Tommy]’s writeup. In it, he explains the various design choices and improvements that went into the POLY555, not just as an instrument, but as a kit intended to be produced and easy to assemble. Good DFM (Design For Manufacturability) takes time and effort, but pays off big time even for things made in relatively small quantities. Anything that reduces complexity, eliminates steps, or improves reliability is a change worth investigating.

For example, the volume wheel is not a thumbwheel pot. It is actually a 3D-printed piece attached to the same potentiometer that the 555s use for tuning; meaning one less part to keep track of in the bill of materials. It’s all a gold mine of tips for anyone looking at making more than just a handful of something, and a peek into the hard work that goes into designing something to be produced. [Tommy] even has a short section dedicated to abandoned or rejected ideas that didn’t make the cut, which is educational in itself. Want more? Good news! This isn’t the first time we’ve been delighted with [Tommy]’s prototyping and design discussions.

POLY555’s design files (OpenSCAD for enclosure and parts, and KiCad for schematic and PCB) as well as assembly guide are all available on GitHub, and STL files can be found on Thingiverse. [Tommy] sells partial and complete kits as well, so there’s something for everyone’s comfort level. Watch the POLY555 in action in the video, embedded below.

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Stochastic Markov Beats

February 20, 2021 by Matthew Carlson 7 Comments

[Attoparsec] has been building intriguing musical projects on his YouTube channel for a while and his latest is no exception. Dubbed simply as “Node Module”, it is a rack-mounted hardware-based Markov chain beat sequencer. Traditionally Markov chains are software state machines that transition between states with given probabilities, often learned from a training corpus. That same principle has been applied to hardware beat sequencing.

Each Node Module has a trigger input, four outputs each with a potentiometer, and a trigger out. [Attoparsec] has a wonderful explanation of all the different parts and theories that make up the module at the start of his video, but the basic operation is that a trigger input comes in and the potentiometers are read to determine the probabilities of each output. One is randomly selected and fired. As you can imagine, there are loops and even dead-end nodes and for some musical pieces there is a certain number of beats expected, so a clever reset signal can be sent to pull the chain back to the initial starting state at a regular interval. The results are interesting to listen to and even better to imagine all the possibilities.

The module itself is an Arduino-based custom PCB that is laid out quite cleanly. The BOM, code, and KiCad files are available on GitHub if you want to make one yourself. This isn’t the first instrument we’ve seen [Attoparsec] make, and we’re confident it won’t be the last.

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Continuous Excitation Piano Machine Looks Nervous, Sounds Grand

February 16, 2021 by Adam Zeloof 20 Comments

It’s not every day we see a grand piano with a Raspberry Pi inside, let alone one with 96 motors, but sometimes we get lucky. The contraption in question is one developed by [Konstantin Leonenko], as part of a collaboration with composer [Patricia Alessandrini] for a piece she created inspired by Ada Lovelace. Specifically, [Patricia] was inspired by Ada’s idea that an “analytical machine” would, someday, be able to create music on its own. [Konstantin] and [Patricia] worked together to make a machine that would learn from it’s human co-performers and create music with them.

Their creation, rather than just one tricked-out keyboard, is actually a portable attachment that can be easily fitted to any grand piano. Each of the device’s 96 motors drives a plastic “finger” that excites the piano’s strings. The result is a sound unlike any other — and you really need to experience it so click through that link at the top for the demo video.

Rather cleverly, the fingers are designed such that their dynamics help to mask the sound of the motor (a must for performances) while simultaneously enhancing the string’s timbre. Like any project, this one went through a number of iterations over the two-year design process, and even spun off into an entirely new, glove-based version.

We’ve seen some awesome music tech hacks, and this one fits right in with the rest. It’s always exciting to see an instrument as ubiquitous as the piano be used in new and refreshing ways. Be sure to check out the link at the top for a video of this incredible instrument in action!

RFID Music Player Gets The Whole House Pumping

February 13, 2021 by Lewin Day 11 Comments

RFID tags are normally used for pedestrian tasks like tracking shipping crates or opening doors to workplaces we’d rather be absent from, but they can also be cool and fun. [hoveeman] demonstrates this ably with a tidy jukebox project.

The build is based on a Raspberry Pi Zero, secreted away underneath a table with a USB RFID reader attached. Atop the table are a series of RFID cards upon which [hoveeman] printed the artwork from his favorite albums using a special caddy in an inkjet printer. Through some Python code and shell scripts, when scanning a card, the Pi Zero is able to trigger all the Google Home compatible devices in the house to play the album selected at the same time.

It’s a visually enjoyable way to cue up some music, and likely more reliable than most voice assistants, too. We can see this being particularly useful for Weezer fans; with the band’s many self-titled releases, Siri and the Google Assistant typically fail to play the right album on request. We’ve seen other beautiful RFID jukeboxes before, but one player that really sticks out ditched the RF and just uses computer vision with vinyl albums as the ID.

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