Getting the finishing details on a Halloween costume completed is the key to impressing friends and strangers alike on the trick-or-treat rounds. Especially when it comes to things like props, these details can push a good Halloween costume to great with the right touches. [Jonathan]’s friend’s daughter will be well ahead of the game thanks to these additions to a toy guitar which is part of her costume this year.

The toy guitar as it was when it arrived had the capability to play a few lackluster sound effects. The goal here was to get it to play a much more impressive set of songs instead, and to make a couple upgrades along the way as well. To that end, [Jonathan] started by dismantling the toy and investigating the PCBs for potential reuse. He decided to keep the buttons in the neck of the guitar despite their non-standard wiring configuration, but toss out the main board in favor of an ESP32. The ESP32 is tasked with reading the buttons, playing a corresponding song loaded on an SD card, and handling the digital to analog conversion when sending it out to be played on the speaker.

The project doesn’t stop there, though. [Jonathan] also did some custom mixing for the songs to account for the lack of stereo sound and a working volume knob, plus he used the ESP32’s wireless capabilities to set the guitar up as a local file server so that songs can be sent to and from the device without any wires. He also released the source code on the project’s GitHub page for anyone looking to use any parts of this project. Don’t forget there’s a Halloween contest going on right now, so be sure to submit the final version of projects like these there!

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.

Since the first of our ancestors discovered that banging a stick on a hollow log makes a jolly sound, we hominids have been finding new and unusual ways to make music. We haven’t come close to tapping out the potential for novel instruments, but then again it’s not every day that we come across a unique instrument and a new sound, as is the case with this string-plucking robot harp.

Named “Greg’s Harp” after builder [Frank Piesik]’s friend [Gregor], this three-stringed instrument almost defies classification. It’s sort of like a harp, but different, and sort of like an electric guitar, but not quite. Each steel string has three different ways to be played: what [Frank] calls “KickUps”, which are solenoids that strike the strings; an “eBow” coil stimulator; and a small motor with plastic plectra that pluck the strings. Each creates a unique sound at the fundamental frequency of the string, while servo-controlled hoops around each string serve as a robotic fretboard to change the notes. Sound is picked up by piezo transducers, and everything is controlled by a pair of Nanos and a Teensy, which takes care of MIDI duties.

Check out the video below and see if you find the sound both familiar and completely new. We’ve been featuring unique instruments builds forever, from not-quite-violins to self-playing kalimbas to the Theremincello, but we still find this one enchanting.

Effects pedals: for some an object of overwhelming addiction, but for many, an opportunity to hack. Anyone who plays guitar (or buys presents for someone who does) knows of the infinite choice of pedals available. There are so many pedals because nailing the tone you hear in your head is an addictive quest, an itch that must be scratched. Rising to meet this challenge are a generation of programmable pedals that can tweak effects in clever ways.

With this in mind, [ElectroSmash] are back at it with another open source offering: the pedalSHIELD MEGA. Aimed at musicians and hackers who want to learn more about audio, DSP and programming, this is an open-hardware/open-software shield for the Arduino MEGA which transforms it into an effects pedal.

The hardware consists of an analog input stage which amplifies and filters the incoming signal before passing it to the Arduino, as well as an output stage which does the DAC-ing from the Arduino’s PWM outputs, and some more filtering/amplifying. Two 8-bit PWM outputs are used simultaneously to make pseudo 16-bit resolution — a technique you can read more about in their handy forum guide.

The list of effects currently implemented covers all the basics you’d expect, and provides a good starting point for writing custom effects. Perhaps a library for some of the commonly used config/operations would be useful? Naturally, there are some computational constraints when using an Arduino for DSP, though it’s up to you whether this is a frustrating fact, or an opportunity to write some nicely optimised code.

[ElectroSmash] don’t just do pedals either: here’s their open source guitar amp.

[Clare] isn’t the most musically inclined person, but she can strum a guitar. Thanks to a little help from an Arduino, she doesn’t even have to do that.

She built the strumbot, which handles the strumming hand duties of playing the guitar. While [Claire] does believe in her strumbot, she didn’t want to drill holes in her guitar, so hot glue and double-sided foam tape were the order of the day.

The business end of the strumbot is a micro servo. The servo moves two chopsticks and draws the pick across the strings. The tiny servo surprisingly does a great job getting the strings ringing. The only downside is the noise from the plastic gears when it’s really rocking out.

Strumbot’s user interface is a 3D-printed case with three buttons and three LEDs. Each button activates a different strum pattern in the Arduino’s programming. The LEDs indicate the currently active pattern. Everything is powered by a USB power pack, making this a self-contained hack.

[Clare] was able to code up some complex strum patterns, but the strumbot is still a bit limited in that it only holds three patterns. It’s good enough for her rendition of “Call Me Maybe”, which you can see in the video after the break. Sure, this is a simple project, not nearly as complex as some of the robotic guitar mods we’ve seen in the past. Still, it’s just the ticket for a fun evening or weekend project – especially if you’re introducing the Arduino to young coders. Music, hacking, and modding – what more could you ask for?

There’s a lot more to learning how to play the guitar than just playing the right notes at the right time and in the right order. To produce any sound at all requires learning how to do completely different things with your hands simultaneously, unless maybe you’re a direct descendant of Eddie Van Halen and thus born to do hammer ons. There’s a bunch of other stuff that comes with the territory, like stringing the thing, tuning it, and storing it properly, all of which can be frustrating and discouraging to new players. Add in the calluses, and it’s no wonder people like Guitar Hero so much.

[Jake] and [Jonah] have found a way to bridge the gap between pushing candy colored buttons and developing fireproof calluses and enough grip strength to crush a tin can. For their final project in [Bruce Land]’s embedded microcontroller design class, they made a guitar video game and a controller that’s much closer to the experience of actually playing a guitar. Whether you’re learning to play for real or just want to have fun, the game is a good introduction to the coordination required to make more than just noise.

In an interesting departure from standard stringed instrument construction, plucking is isolated from fretting.  The player fingers notes on four strings but plucks a special, fifth string with a conductive pick that closes the plucking circuit. By contrast, the fretting strings are normally high. When pressed, they contact the foil-covered fingerboard and the circuit goes low. All five strings are made of carbon-impregnated elastic and wrapped with 30AWG copper wire.

All five strings connect to an Arduino UNO and then a laptop. The laptop sends the signal to a Bluefruit friend to change Bluetooth to UART in order to satisfy the PIC32. From there, it goes out via 2-channel DAC to a pair of PC speakers. One channel has the string tones, which are generated by Karplus-Strong. To fill out the sound, the other DAC channel carries undertones for each note, which are produced by sine tables and direct digital synthesis. There’s no cover charge; just click past the break to check it out.

If you’d like to get into playing, but don’t want to spend a lot of money to get started, don’t pass up those $30-$40 acoustics for kids, or even a $25 ukulele from a toy store. You could wind your own pickup and go electric, or add a percussive solenoid to keep the beat.

Not only does the GuitarBot project show off some great design, but the care given to the documentation and directions is wonderful to see. The GuitarBot is an initiative by three University of Delaware professors, [Dustyn Roberts], [Troy Richards], and [Ashley Pigford] to introduce their students to ‘Artgineering’, a beautiful portmanteau of ‘art’ and ‘engineering’.

The GuitarBot It is designed and documented in a way that the three major elements are compartmentalized: the strummer, the brains, and the chord mechanism are all independent modules wrapped up in a single device. Anyone is, of course, free to build the whole thing, but a lot of work has been done to ease the collaboration of smaller, team-based groups that can work on and bring together individual elements.

Some aspects of the GuitarBot are still works in progress, such as the solenoid-activated chord assembly. But everything else is ready to go with Bills of Materials and build directions. An early video of a strumming test proof of concept used on a ukelele is embedded below.

GuitarBot would fit right in to a band where only the instruments operate unplugged. Speaking of robot bands, don’t forget the LEGO-enabled Toa Mata, or the fully robotic group Compressorhead.

Musical festivals are fun and exciting. They are an opportunity for people to perform and show-off their art. The Boulevardia event held this June in Kansas City was one such event, where one of the interactive exhibits was a 12-foot guitar that could be played. [Chris Riebschlager] shares his experience making this instrument which was intended to welcome the visitors at the event.

The heart of this beautiful installation is a Bare Conductive board which is used to detect a touch on the strings. This information is sent over serial communication to a Raspberry Pi which then selects corresponding WAV files to be played. Additional arcade buttons enable the selection of playable chords from A through G, both major and minor and also give the option to put the guitar in either clean or dirty mode.

The simplicity of construction is amazing. The capacitive touch board is programmed using the Arduino IDE and the code is available as a Gist. The Raspberry Pi runs a Python script which makes the system behave like an actual guitar i.e. touching and holding the strings silences it while releasing the strings produces the relevant sound. The notes being played were exported guitar notes from Garage Band for better consistency.

The physical construction is composed of MDF and steel with the body and neck of the guitar milled on a CNC machine. Paint, finishing and custom decals give the finished project a rocking appearance. Check out the videos below for the fabrication process along with photos of the finished design.

This project is a great example of art enabled by technology and if you love guitars, then go ahead and check out Brian May’s Handmade Guitar.

Construct an Arduino guitar pedal stompbox with easy-to-find parts and you'll be having fun creating your own sounds in not time.

Read more on MAKE

The post Build an Arduino Guitar Pedal Stompbox appeared first on Make: DIY Projects and Ideas for Makers.

Ever since Jimi Hendrix brought guitar distortion to the forefront of rock and roll, pedals to control the distortion have been a standard piece of equipment for almost every guitarist. Now, there are individual analog pedals for each effect or even digital pedals that have banks of effects programmed in. Distortion is just one of many effects, and if you’ve built your own set of pedals for each of these, you might end up with something like [Brian]: a modular guitar pedal rack.

Taking inspiration from modular synthesizers, [Brian] built a rack out of wood to house the pedal modules. The rack uses 16U rack rails as a standard, with 3U Eurorack brackets. It looks like there’s space for 16 custom-built effects pedals to fit into the rack, and [Brian] can switch them out at will with a foot switch. Everything is tied together with MIDI and is programmed in Helix. The end result looks very polished, and helped [Brian] eliminate his rat’s nest of cables that was lying around before he built his effects rack.

MIDI is an extremely useful protocol for musicians and, despite being around since the ’80s, doesn’t show any signs of slowing down. If you want to get into it yourself, there are all kinds of ways that you can explore the studio space, even if you play an instrument that doesn’t typically use MIDI.