Arduino Laser Show (adapted from NothingLabs' Instructable)

This project uses an Arduino, a pair of speakers, and a laser pointer to create a laser projector able to trace out designs in a dark room. To power it, I've cannibalized a PC ATX power supply capable of delivering plenty of current for the speakers.

Most of this project was directly adapted from the excellent Arduino Laser Show with Full X-Y Control by Rich Olson / nothinglabs.

 

About me: I'm Joseph Long, a physics student at Pomona College in Claremont, CA. This was made as my final project for our electronics class. I owe a great deal of thanks to my professor, Dr. Dwight Whitaker; our machinist, Glenn Flohr; our electrician, Tony Grigsby; our TA, Jonathan Raiman; Dr. Kwok; and all of my classmates.

Step 1: The Big Idea

Laser projectors are devices that can change the position of a projected laser 'point' very quickly to draw out pre-programmed shapes. In the big, expensive world of professional projectors, this is accomplished not (as I had thought) by moving the laser itself, but by precisely rotating mirrors to change its deflection. The components used to precisely position the mirrors are called "galvos", and are not too different from the galvanometers (i.e. volt meters) you may have encountered in your high school physics class.

Unfortunately, procuring galvos can be really expensive (especially getting just two for a project)! Instead, we're going to use regular old speakers to move our mirrors. And we're going to use the Arduino to adjust the speakers so fast that they'll create the kind of persistent image we want.