Artemis Synthesizer Kit

October 13, 2012 by Eric Evenchick 14 Comments

The Artemis Synthesizer was created as a kit for Boston University’s Artemis Project. This project aims to teach female rising high school freshmen about computer science with hands-on activities. [Chris] based the kit on a ATMEGA328P microcontroller and a MCP4921 digital to analog converter. It can be used in a keyboard mode, where the buttons toggle various notes of the scale, or in a sequencer mode, where the buttons are used to toggle pre-programmed sequences.

[Chris] wanted the kit to be usable by the students after the workshop, so he used an optical link dubbed the “Optoloader” to program new sequences and waveforms into the device. A web based application allows for waveforms and sequences to be built in the browser, then programmed by holding a phototransistor up to a blinking square. The square flashes black and white corresponding to a Biphase Mark Code encoded message. This is decoded by the microcontroller on the synthesizer and stored in memory. As a result, no special hardware is needed to play new waveforms and sequences.

[Chris] has a thorough write up for the project, including feedback surveys from the students. He plans to add more specific information about the Optoloader in the future.

Check out a video of the kit in action after the break.

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Arduino Voice Changer Turns You Into [Vader]

October 12, 2012 by Brian Benchoff 12 Comments

Halloween is just around the corner, so of course we’re looking forward to a bunch of awesome costumes put together by Hackaday readers. In an effort to match his voice to his costume, [Phil Burgess] over at Adafruit (and former Hackaday alumnus) put together an Arduino-powered voice changer to give his voice the gravitas of [James Earl Jones] or the lightheartedness of a member of the Lollipop Guild.

If you’ve ever played with a turntable, you’ll know playing a 33 RPM record at 45 or 78 RPM turns your treasured copy of Dark Side of the Moon into a lighthearted aural experience with a pitch that is much too high. Likewise, playing a single at 33 or 16 RPM means those once dulcet tones are now recordings of tormented souls in an acoustic hell.

[Phil]’s voice changer operates on the same principle by recording sounds from a microphone into a circular array and playing them back at a different rate; faster if the desired effect is a Munchkin, and slower if this year’s Halloween costume will be a Sith lord.

The completed build incorporates a 10k pot to dynamically change the timbre of the voice changer, as well as an Adafruit Wave Shield to play back a few pre-recorded sounds of lightsabers clashing. In all, a very cool project for your Halloween costume that’s also a very good introduction to DSP and real-time audio modifications with a microcontroller.

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Putting Guitar Pedals In A Web Page

October 10, 2012 by Brian Benchoff 13 Comments

Only half of playing guitar – according to a few musician friends of mine – is moving your fingers up and down a fretboard and banging out some chords. The other half is the artistry of mastering your tone, usually through amp settings and stomp boxes.

Effects pedals – little boxes of electronics that go between the guitar and amp – are able to amplify and distort a guitar’s output, add reverb and delay, and even filter the tone via a wha or envelope pedal. These pedals can be simulated in software, but we can’t believe that they can now be emulated completely in JavaScript.

Pedalboard.js is a project put together by [dashersw], and aims to put a slew of pedals ‘in the cloud’ and turn editing and effects board as easy as building a web page.

The project is built around Webkit’s W3C audio API, allowing this virtual pedal board to work in Chrome, Safari, and other Webkit-enabled browsers. Pedals are programmed as nodes, each configurable to have and input, output, or analyzer that is able to modify the gain, wave shape, or filter of anything received by the line in on your computer.

Thee is a small demo of Pedalboard.js available here with a pre-recorded guitar track feeding into a few stomp boxes. It’s a pretty cool idea if you’d like to play around with a few guitar effect, but we can’t wait to see this bit of JavaScript implemented by effects pedal manufacturers allowing us to try before we buy.

LED Illuminated Isomorphic Keyboard Looks As Good As It Sounds

October 5, 2012 by Brian Benchoff 15 Comments

Unlike the traditional ebony and ivory found on pianos, isomorphic keyboards arrange buttons on a grid. This makes every chord the same shape, and to transpose a piece it’s simply a matter of moving your fingers a few places to the left or right. [Brett Park] sent in an isomorphic keyboard he built loaded up with LEDs, and we’re thinking it the perfect instrument for musicians looking to move up from playing their MacBook.

The body of [Brett]’s keyboard is made out of a sheet of acrylic. After drilling 64 holes for each of the clear arcade buttons, [Brett] bent the sides of his hexagonal keyboard into a very sturdy-looking enclosure.

On the hardware side, [Brett] used a 64 button Arduino shield and a Sparkfun MIDI shield. The RGB LEDs behind each button are controlled via MIDI sysex messages generated outside the instrument, making it perfect for a little bit of visual feedback from whatever soft synth you desire.

In the videos after the break, you can check out the light patterns in action along with one of [Brett]’s improvs. Notice how all the chords are the same shape, and changing the key only requires [Brett] to move his hands slightly to the side.

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LEGO Record Player

October 3, 2012 by Eric Evenchick 7 Comments

Some people claim that the sound of vinyl is superior to digital playback. While this hack wont win any awards for audio quality, [Ryan]’s LEGO Record Player is a unique use of one of our favorite toys. Most of the components including the tone arm, counterweight, and base, are built entirely of LEGO. A large gear from an educational construction set is used for the platter. Unfortunately, the rotation isn’t terribly smooth, and the playback is rather distorted.

The turntable uses a standard cartridge and stylus, which should allow it to be connected to any receiver with a phono preamplifier. Using these off the shelf parts, it’s possible to build the mechanical components a turntable out of a variety of things. As the video demonstrates, getting the platter to turn correctly is a bit of a challenge.

Check out a video of the wobbly playback featuring Cindy and Bert after the break.

Via Make

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MIDI Man-in-the-middle Hack Lets You Add Pedal To The Mix

September 26, 2012 by Mike Szczys 8 Comments

[Sebastian] has a friend who would like to use a pedal with his MIDI setup, but his keyboard doesn’t support one. Some might interpret that as a sign you need to buy a new keyboard. But [Sebastian] has already done a lot of work with the MIDI protocol. He knew it should be possible to create a MIDI pass-through which adds support for a pedal.

You can see the two MIDI cables connected to the box above. One is the input from the keyboard, the other is the output to the synthesizer. There is also a jack for a pedal input to the left. The chip inside intercepts each packet, rolling in values based from the pedal input and passing on the altered packets to the synthesizer. As you can hear in the video after the break, this works like a charm.

Catch more of [Sebastian’s] midi work by following his keyboard sensor replacement projects.

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BaceMaker Weds Organ Foot Pedals With Guitar Whammy Effects

September 24, 2012 by Mike Szczys 7 Comments

[Jon Ferwerda] managed to fry the analog electronics on an old electric organ while conducting some circuit bending experiments. It’s a loss, but he’s still left with some cool equipment to play with. Recently he got to work generating tones using the organ’s foot pedals.

There were two types of foot pedal included with this organ, the set that is arranged like a keyboard, and a rocker pedal similar to what you might use with an electric sewing machine. Since the music generation was handled by those fried bits of organ [Jon] got to work interfacing the foot keyboard with a 555 timer. He used a fairly large capacitor to get the frequency into the bass range and wired individual pedals to different parts of a resistor network. But he didn’t stop with that. The rocker pedal has its own variable resistor hardware which lets him bend the pitches are they are being generated which sounds alike like a guitar whammy effect. He shows his work in the clip after the break. We think he nailed it! This is a perfect supplement to any type of electronic music setup.

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