Floppy Drive As An Audio Sampler

April 12, 2012 by Mike Szczys 7 Comments

Here’s a floppy drive which is being used as an audio sampler. At first glance we thought this was another offering which drives the stepper motor at a specific frequency to generate that characteristic sound at a target pitch. But that’s not what’s happening at all. The floppy is actually being used as a storage device (go figure).

From what we can tell, it’s being used almost like an 8-track tape. A PWM signal is stored on one circular slice of the disk, then the head can be moved back to that same “track” to play back the wave form. The head doesn’t move during playback, but just keeps reading the same track of bits. To the right you can see an Arduino board. This allows for MIDI control of the track selection. [Alexis] shows off some keyboard control in the video after the break. There’s a buffer chip on the breadboard which allows the audio output to be quickly switched off as the floppy drive head is moved. This keeps garbage out of the sound until the new track can be read.

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A “Jukebox” In A Bell Jar

April 10, 2012 by Jeremy Cook 23 Comments

[Tim] wrote in to tell us about his Mark III hard drive in a bell jar, and we were quite impressed! The principle of using a bell jar to protect the hard drive inside so the world can see it spinning is really a cool idea, but his execution of this project is excellent. It was reportedly so good that an unnamed college actually asked him to build one of his drive displays for them.

The Mark III is an excellent build, and the little hard drive has been swapped to the front of it for better visualisation. The disadvantage of the iPod Mini used for the Mark III build is that it actually buffers enough so that the read head doesn’t have to spin during the entire song. Because of this, we thought that his first build, nicknamed [pink], was even more interesting, if ever so slightly less refined. By many of our hacking standards though, both are incredibly finished works of art!

Both these builds feature a plethora of LEDs to keep you entertained, and can be seen demonstrated after the break! Continue reading “A “Jukebox” In A Bell Jar” →

Quick And Easy Arduino-powered Theremin

April 5, 2012 by Brian Benchoff 19 Comments

[Martin] sent in a great guide to a simple Arduino based theremin. It’s a very small build – just a single common IC and some passive components – and easy enough to build in an afternoon.

The theremin is based on a simple LC oscillator built around a 7400 quad NAND gate IC, a wire antenna, and a few caps and resistors. When a hand moves closer to the antenna, the frequency of the oscillator increases; when a hand moves away, the frequency decreases. On the software side, the oscillator is connected to the internal hardware counter of the Arduino. Every time there’s a change in the voltage output by the oscillator (all the time, varying slightly with the distance from a hand to the antenna), the counter increases by one. This counter is tallied up over 1/10th of a second, and the distance from the instrumentalist to the theremin can be determined. From there, it’s just outputting a frequency to a speaker.

All the code, schematics, and board layouts are available on [Martin]’s guide, and most of our readers probably have the parts to build this lying around their workbench. You can check out a video of [Martin]’s theremin in action on his guide.

Recorder Controlled Snake Game Played On A Nokia 6110

April 3, 2012 by Mike Szczys 7 Comments

Dig out an old cell phone, hit the dollar store for some plastic recorders, and build this sound controlled snake game for your next party. The project will be a snap for those comfortable working with microcontrollers, and a great learning experience if you’re looking to try your first Arduino project.

[László] and his friend call the project the Snake Charmer. As shown in the clip after the jump it uses music notes to direct the path of the solid line in the classic cellphone game of snake. But this isn’t just some PC-based rip-off. They’re playing on the actual cellphone. A camera points at the screen to project it for the enjoyment of spectators. The control scheme uses relays soldered to the pads of the four directional buttons. The pitches are being detected by a Max/MSP program, with the corresponding commands pushed to the Arduino via USB. Yep, it’s overkill but the point was to get this up and running quickly and with a minimum of work. We’d say they succeeded.

Actually, now that we think of it, this isn’t a two player game. Perhaps the recorder control concept needs to be applied to a more modern version of the game.

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DrummerBot Joins The Jam Session When Your Bandmates Are Busy

April 3, 2012 by Mike Nathan 10 Comments

drummerbot

It seems that more often than not, [Steffest] finds himself inspired to rock out on his guitar without a percussion section to back him up. Like any enterprising hacker/musician would be wont to do, he built a robotic drummer to join in when he got the urge to play.

His DrummerBot is driven using an Arduino, which is tasked with controlling the 8 servo motors that the bot has at its disposal. The bot’s drum set is composed of a variety of items from fan motors to pot lids and more. [Steffest] wanted the ability to produce the maximum variety of sounds possible, so most of the servo motors are driven in two directions allowing the bot to strike more than one item with each “arm”.

[Steffest] is a big fan of interfacing physical objects with a web interface, so he built a simple HTML based sequencer that allows him to program the robot from his phone. Once the sequencer is programmed, the DrummerBot can be launched into action with the simple press of a button.

[Steffest] says that the bot works pretty well, but the sound is a bit raw if you hear it live. A little Ableton Live post-processing goes a long way to smooth things out however, as you can see in the video below.

[Thanks, Wesley]

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Slide Rule For Musical Scales

April 2, 2012 by Mike Szczys 23 Comments

For all those engineers who dabble in music [Magnetovore] has your back. Musicians simply must know their scales and he came up with a papercraft slide rule for major and minor scales.

The system is very easy to use. He’s uploaded PDF files that let you print out the mask for the top layer and bar chart and directions for the bottom layer. The top layer is laid out like a piano keyboard, with windows for each key and a couple of windows to identify the major and minor scales being displayed. Just slide the mask until each key is a solid color. The color codes show the tonic, third, and dominant for each key so you know where to start. In the video after the break you can see how it works by playing all of the non-black keys in order. But wait, if you order now you’ll get the slide rule for Cello scales at the same low-cost; free!

This is a fun quick-reference, but you really should know your Circle of Fifths. Continue reading “Slide Rule For Musical Scales” →

Trumpet Hero

March 29, 2012 by Mike Szczys 4 Comments

[Evilsigntist] combined an old cornet with an old PS2 guitar hero controller to produce the Trumpet Hero. The fragile looking conglomeration really brings a smile to our faces. Just make sure the instrument has already seen the end of its days before drilling holes to mount the various parts.

In the image above you can see that the three valve buttons have been painted to correspond to frets on the original guitar controller. The orange and blue frets are positioned for the left hand to operate. There seems to be a couple of different version because there is a diagram showing a mute in the bell that can be twisted for whammy bar input, but that’s not shown here. Strumming is accomplished by blowing through the mouthpiece, but as you can see in the video after the break, no buzzing is necessary.

Using actual instruments as game inputs is a lot of fun. We always think back to the flute and drum set controllers for Rock Band.

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