Laser Harp

December 23, 2009 by Mike Szczys 12 Comments

[Jared] had a bunch of lasers left over from a previous project that he put to use by producing this laser harp. The look of it reminds us of a very small Koto or perhaps an Autoharp (although the chords can’t be changed on this model).

We’re so glad that [Jared] spent the time to produce such a fine looking body for the instrument. The strings that would traditionally produce the sound on a harp have been replaced with laser diodes shining at Cadmium Sulfide photo resistors. When a beam of light is broken, an Arduino detects the change via the CdS cell and plays a sound through an Altec Lansing speaker inside of the case.

Unfortunately there’s no video available but we’re pretty sure it makes a “pew-pew” sound. There is a link to download the source code but it points to the overview page instead of downloadable code. From the fritzing diagram the CdS cells are part of a voltage divider which provides digital logic to the Arduino. That should be pretty easy to replicate even without seeing [Jared’s] code and we’re sure you can source other Arduino instrument projects for tips on wave shield or midi functionality.

[Thanks The Cheap Vegetable Gardener]

A Random USB… Hourglass

December 21, 2009 by Jake W 20 Comments

[Peter] thought of a creative, way to generate random entropy for under $100.

The USB Hourglass combines a sand timer with a rotating mechanism and an optical beam through the center of the timer to observe the falling sand. The amount of light reaching a detector is digitized at frequent intervals and processed by a microcontroller to determine when to rotate the hourglass. The digitized light levels are also sent by USB to a host PC where they can be used as a source of random entropy. Power is supplied over the USB cable.

With the USB Hourglass, the user can look at the sand falling through the center of the hourglass and monitor the randomness in the USB output data. And one can read the code line-by-line, compile it, and upload it to the microcontroller using only open-source and widely supported tools.

Scan Room, Explore Virtually

December 16, 2009 by Caleb Kraft 6 Comments

[Patrick] directed us to his project for alternate realism. The final goal is to be able to walk around in a space wearing a head mounted display, exploring a virtual representation of that space. This virtual representation could be altered, stylized, augmented and modified in countless ways. It is an exploration in perception, similar to enjoying different styles of painting, we could enjoy different styles of viewing a real space. Currently, it isn’t quite real time. He has to scan a room with a somewhat bulky device, then plug into his display to explore it. Being able to scan quickly and reliably enough shouldn’t be far off. [Patrick] notes that others have done almost real time scans at home already.

Set Phasers To “blind”

November 12, 2009 by Mike Szczys 30 Comments

[Directive0] added a 200mW laser to his Enterprise Phase Pistol toy. This joins the ranks of hand-held laser hacks that we’ve seen around here lately. His build makes use of the stun and kill settings of the toy to switch between different modes. The built-in 9 volt battery holder is tapped into for power. When set to stun, the stun LED indicator is illuminated and a trigger pull sends current limited electricity to the laser diode. When the kill (or blind) setting is selected, the appropriate LED is illuminated and the trigger sends the full current from the battery to the laser diode. Power regulation is managed by the driver circuit for the laser.

This build preserves the unmodded look of the toy gun. [Directive0’s] inclusion of protective glass should fend off the warnings we usually see in the comments of these types of hacks.

Laser Etching Fruit

November 5, 2009 by Caleb Kraft 22 Comments

laserlable-ed02 (Custom)

Ever annoyed by those pesky stickers on your fruit? They never seem to pull off in one piece and they always leave a little glue behind. Well, the industry might be moving away from them in favor of laser etching each piece of fruit. They are using a low energy carbon dioxide laser to etch the skin. The FDA is in the final stages of approval for using this in the states. It is already in use in New Zealand. We might find this a bit weird, but we’ve seen weirder.

[via slashdot]

DIY Plotter With Laser

October 25, 2009 by Mike Szczys 39 Comments

plotter-with-300w-laser

[Viacheslav] built a plotter that is fast and accurate. He wanted to take it one step further and added a laser in place of the pen. The 300 mW unit does a nice job of wood-burning any pattern sent to it, but isn’t strong enough to serve as a laser cutter for anything other than thin-film. We wonder if it can be used to cut solder paste stencils for surface mount PCB production.

In the video after the break you can see some plotting that uses a pen. In addition to writing on paper, [Viacheslav] has tested this as a method of applying etch resist to a copper clad board for PCB production. He’s able to achieve 0.8 mm pitch but the production process is limited by the resist pen’s tendency to wear out quickly and to only prevent etching for a short period of time (compared to toner transfer resist).

Just like with his touch sensitive keypad project, he’s taken the time to thoroughly document his work. Build notes, pictures, CAD files, and source code are all available for your perusal and hackage.

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Laser Raygun Boasts 300mW, Hunts Klingons

October 18, 2009 by Mike Szczys 39 Comments

Phasers come with two settings: stun and kill. [Luke] took this seriously when he put two Blu-ray lasers into a toy raygun. He picked up the toy from Amazon for about twenty bucks and set to work.

The laser diodes are both pulled out of a 6x BD-R burner, which we think is a pretty expensive source to scavenge from. [Luke] removed the toy circuitry, reusing the trigger, top switch, and battery pack. The two diodes are mounted on a swiveling carriage which is turned 180 degrees to switch between the two diodes. A boost driver converts the 3v from the batteries up to 7v for the diodes.

This is a skillful conversion and [Luke] should be proud. Don’t miss the video after the break and if you’re thirsty for more take a look at the last hand held laser we featured.

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