You Built What?!
A floor-to-ceiling virtual instrument that can rock for real

The Thin Green Line A fog machine next to the harp makes the beams show up more clearly. Stephen J. Hobley

Playing the harp isn’t the most high-tech pastime—unless, like Stephen Hobley, you use lasers in place of the strings. Though not the first home-built laser harp, Hobley’s creation is unquestionably the coolest. Played by disrupting the laser beams with his hands, it can produce just about any sound. Better yet, it’s also a fully functioning controller for a version of Guitar Hero.

The harp consists of a box with a power supply, a 450-milliwatt green laser, a mirror and a motherboard. After determining the beam’s frequency, Hobley was able to tune a sensor so it would detect only the laser and not any ambient light. Touching a beam deflects light toward the sensor, triggering software on a PC that translates hand movements into sounds. He also wrote a script that maps notes from the harp to keyboard controls in the videogame.

Hobley is now selling the plans for the harp on his Web site (stephenhobley.com). He says he’s recently had to upload a video of himself playing the game: “It was a direct response to all the comments I got to ‘play Freebird!’”

Check out the video below, then turn the page to see how it works.


single page
Page 1 of 2 12next ›last »
Want to read more articles like this, plus tips and tricks, home hacks, DIY projects, and more? Subscribe to Popular Science today, for less than $1 per issue!

9 Comments

I'm surprised this became news because the laser harp was already invented in 1980. Jean Michel Jarre used it in almost every of his concerts : http://en.wikipedia.org/wiki/Laser_harp

That is way cool and I can see how it would lead to some pretty neat stuff but atm its kinda boring :)

Moshable Music

Why not orbit magnetic wands that suck the debris out of orbit? Using large orbiting magnets makes more sense, and would cost far less!

hey thats pretty cool

it looks more like laser drums the way he's playing it.

hammer-ons? hammer offs? nerd power?

This guy really sucks at that game, I used to have a friend that was really into this game. I would go over and we would play 2 player, he used the guitar and I always got stuck with just the controller. I got pretty good at it though and was able to play this song, Freebird, on hard mode for perfect just once. Always better than that though, but I see where this would be a big seller for that crowd. Hell my friend would buy it, maybe I would get some guitar time... Not really, just not my thing really anymore. Is cool idea, would not call it the harp though, that will discourage his target crowd. Needs a cooler name.

Wow,Very cool. But I would like to know how you would sync the laser harp, so you can play the notes. This is so cool though!

@sleidia
I have awesome HD concert video of Jean Michel Jarre in Morocco using his laser "harp" over the audience.
http://www.youtube.com/watch?v=hJn_6akNLqc

Test-tube babies, I got rabies
My mother gave birth in a diesel haze

Popular Tags

Regular Features



June 2013: American Energy Independence

Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.


Online Content Director: Suzanne LaBarre | Email
Senior Editor: Paul Adams | Email
Associate Editor: Dan Nosowitz | Email
Assistant Editor: Colin Lecher | Email
Assistant Editor: Rose Pastore | Email

Contributing Writers:

Kelsey D. Atherton | Email
Francie Diep | Email
Shaunacy Ferro | Email

circ-top-header.gif
circ-cover.gif
bmxmag-ps