Auto Strummer Can Plectrum The Whole Flat-Strumming Spectrum

May 7, 2021 by Kristina Panos 3 Comments

Playing the guitar requires speed, strength, and dexterity in both hands. Depending on your mobility level, rocking out with your axe might be impossible unless you could somehow hold down the strings and have a robot do the strumming for you.

[Jacob Stambaugh]’s Auto Strummer uses six lighted buttons to tell the hidden internal pick which string(s) to strum, which it does with the help of an Arduino Pro Mini and a stepper motor. If two or more buttons are pressed, all the strings between the outermost pair selected will be strummed. That little golden knob near the top is a pot that controls the strumming tempo.

[Jacob]’s impressive 3D-printed enclosure attaches to the guitar with a pair of spring-loaded clamps that grasp the edge of the sound hole. But don’t fret — there’s plenty of foam padding under every point that touches the soundboard.

We were worried that the enclosure would block or muffle the sound, even though it sits about an inch above the hole. But as you can hear in the video after the break, that doesn’t seem to be the case — it sounds fantastic.

Never touched a real guitar, but love to play Guitar Hero? There’s a robot for that, too.

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Building A Robotic Band To Make Up For Lack Of Practice

May 6, 2021 by Danie Conradie 6 Comments

Learning to play a musical instrument well requires a significant time investment. [Ivan Miranda] had dreamt of doing this but made peace with the fact that his talents and motivation lay in building machines. However, he has decided to play to his strengths and is building a robotic band. See the videos after the break.

So far he has mechanized a hi-hat, snare drum, and a very basic guitar. The guitar is nothing more than a single string stretched across an aluminum frame, with an electronic pickup. Most of the work has gone into the solenoid-driven picking mechanism. He wanted to avoid picking the string when the solenoid is turned of, so he created a simple little mechanism that only comes in contact with the string when it’s moving in one direction. A bistable solenoid might be a simpler option here.

For the high hat, [Ivan] built a custom stand with two bistable solenoids to lift and drop the top cymbal. A solenoid-driven drumstick was also added. The snare drum uses a similar mechanism, but with a larger solenoid. So far he hasn’t really worked on a control system, focusing mainly on electronics.

[Ivan] points out several times that he has knows very little about making music, but we do enjoy watching him explore and experiment with this new world. Usually, his projects involve a lot more 3D printing, like when he built a giant nerf bazooka or a massive 3D printed tank. Continue reading “Building A Robotic Band To Make Up For Lack Of Practice” →

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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Hackaday Links: January 10, 2021

January 10, 2021 by Dan Maloney 36 Comments

You know that feeling when your previously niche hobby goes mainstream, and suddenly you’re not interested in it anymore because it was once quirky and weird but now it’s trendy and all the newcomers are going to come in and ruin it? That just happened to retrocomputing. The article is pretty standard New York Times fare, and gives a bit of attention to the usual suspects of retrocomputing, like Amiga, Atari, and the Holy Grail search for an original Apple I. There’s little technically interesting in it, but we figured that we should probably note it since prices for retrocomputing gear are likely to go up soon. Buy ’em while you can.

Remember the video of the dancing Boston Dynamics robots? We actually had intended to cover that in Links last week, but Editor-in-Chief Mike Szczys beat us to the punch, in an article that garnered a host of surprisingly negative comments. Yes, we understand that this was just showboating, and that the robots were just following a set of preprogrammed routines. Some commenters derided that as not dancing, which we find confusing since human dancing is just following preprogrammed routines. Nevertheless, IEEE Spectrum had an interview this week with Boston Dynamics’ VP of Engineering talking about how the robot dance was put together. There’s a fair amount of doublespeak and couched terms, likely to protect BD’s intellectual property, but it’s still an interesting read. The take-home message is that despite some commenters’ assertions, the routines were apparently not just motion-captured from human dancers, but put together from a suite of moves Atlas, Spot, and Handle had already been trained on. That and the fact that BD worked with a human choreographer to work out the routines.

Looks like 2021 is already trying to give 2020 a run for its money, at least in the marketplace of crazy ideas. The story, released in Guitar World of all places, goes that some conspiracy-minded people in Italy started sharing around a schematic of what they purported to be the “5G chip” that’s supposedly included in the SARS-CoV-2 vaccine. The reason Guitar World picked it up is that eagle-eyed guitar gear collectors noticed that the schematic was actually that of the Boss MetalZone-2 effects pedal, complete with a section labeled “5G Freq.” That was apparently enough to trigger someone, and to ignore the op-amps, potentiometers, and 1/4″ phone jacks on the rest of the schematic. All of which would certainly smart going into the arm, no doubt, but seriously, if it could make us shred like this, we wouldn’t mind getting shot up with it.

Remember the first time you saw a Kindle with an e-ink display? The thing was amazing — the clarity and fine detail of the characters were unlike anything possible with an LCD or CRT display, and the fact that the display stayed on while the reader was off was a little mind-blowing at the time. Since then, e-ink technology has come considerably down market, commoditized to the point where they can be used for price tags on store shelves. But now it looks like they’re scaling up to desktop display sizes, with the announcement of a 25.3″ desktop e-ink monitor by Dasung. Dubbed the Paperlike 253, the 3200 x 1800 pixel display will be able to show 16 shades of gray with no backlighting. The videos of the monitor in action are pretty low resolution, so it’s hard to say what the refresh rate will be, but given the technology it’s going to be limited. This might be a great option as a second or third monitor for those who can work with the low refresh rate and don’t want an LCD monitor backlight blasting them in the face all day.

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A Pair Of Steppers Are Put To Work In This Automatic Instrument Pickup Winder

December 13, 2020 by Dan Maloney 7 Comments

For something that’s basically a coil of wire around some magnetic pole pieces, an electric guitar pickup is a complicated bit of tech. So much about the tone of the instrument is dictated by how the pickup is wound that controlling the winding process is something best accomplished with a machine. This automatic pickup winder isn’t exactly a high-end machine, but it’s enough for the job at hand, and has some interesting possibilities for refinements.

First off, as [The Mixed Signal] points out, his pickups aren’t intended for use on a guitar. As we’ve seen before, the musical projects he has tackled are somewhat offbeat, and this single-pole pickup is destined for another unusual instrument. That’s not to say a guitar pickup couldn’t be wound on this machine, of course, as could inductors, solenoids, or Tesla coils. The running gear is built around two NEMA-17 stepper motors, one for the coil spindle and one for the winding carriage. The carriage runs on a short Acme lead screw and linear bearings, moving back and forth to wind the coil more or less evenly. An Arduino topped with a CNC shield runs the show, allowing for walk-away coil winding.

We do notice that the coil wire seems to bunch up at the ends of the coil form. We wonder if that could be cured by speeding up the carriage motor as it nears the end of the spool to spread the wire spacing out a bit. The nice thing about builds like these is the ease with which changes can be made — at the end of the day, it’s just code.

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Infinity Mirror Guitar Shreds Forever

November 9, 2020 by Kristina Panos 5 Comments

Just when we thought there was nothing left to make into an infinity mirror, [Burls Art] goes and builds something that seems obvious now that it exists — an infinity mirror guitar. Check out the build video after the break, where [Burls Art] gets right to it without wasting any time.

He started by making a 3/4″ wood frame for the body and the one-piece neck and headstock. The acrylic on the top has two-way mirror film, and the back piece is painted with mirror paint to get the infinity effect going. [Burls Art] also fashioned acrylic boxes for the pickup and the electronics. Those are both buffed to be frosty, so the lights reflect nicely off of them.

There’s nothing super-fancy going on with the electronics, just some app-controlled RGB LEDs. We would love to see a version where the LEDs respond in real time to the music. The effect is still quite cool, so if you don’t want to watch the whole build, at least check out the demo at the end where [Burls Art] plays a riff. Never has a delay pedal been so appropriate.

If you’re not much of a luthier, don’t fret about not being able to make a cover version. We’ve seen plenty of infinity mirrors, but if you want something useful, whip up some infinity drink coasters.

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Axe Hacks: Spinning Knobs And Flipping Switches

October 15, 2020 by Sven Gregori 15 Comments

From a guitar hacking point of view, the two major parts that are interesting to us are the pickups and the volume/tone control circuit that lets you adjust the sound while playing. Today, I’ll get into the latter part and take a close look at the components involved — potentiometers, switches, and a few other passive components — and show how they function, what alternative options we have, and how we can re-purpose them altogether.

In that sense, it’s time to heat up the soldering iron, get out the screwdriver, and take off that pick guard / open up that back cover and continue our quest for new electric guitar sounds. And if the thought of that sounds uncomfortable, skip the soldering iron and grab some alligator clips and a breadboard. It may not be the ideal environment, but it’ll work.

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