Planet Arduino

Bouncing a laser off of a spinning mirror creates an amazing effect with smoke and fog, but YouTuber “Normal Universe” made it even better with an Arduino.

This video starts out by introducing the concept of “laser sky,” which seems like a fun idea. There is, however, a chance that the mirrors wouldn’t spin, potentially pointing a laser continuously at a bystander, possibly damaging his or her eyes. To prevent this, the YouTuber added a photoresistor and LED to sense the spinning mirrors, then programmed an Arduino Uno to cut off the laser if it’s stopped for whatever reason.

Normal Universe goes on to explain the electronic concept behind it as well as the Arduino code involved, so even if this effect isn’t your cup of tea, the photoresistor/voltage divider setup could still be quite useful.

You can find a detailed breakdown of the project in the video below!

There’s just something about wielding a laser pointer on a dark, foggy night. Watching the beam cut through the mist is fun – makes you feel a little Jedi-esque. If you can’t get enough of lasers and mist, you might want to check out this DIY “laser sky” effect projector.

The laser sky effect will probably remind you of other sci-fi movies – think of the “egg scene” from Alien. The effect is achieved by sweeping a laser beam in a plane through swirling smoke or mist. The laser highlights a cross section of the otherwise hidden air currents and makes for some trippy displays. The working principle of [Chris Guichet]’s projector is simplicity itself – an octagonal mirror spun by an old brushless fan motor and a laser pointer. But after a quick proof of concept build, he added the extras that took this from prototype to product. The little laser pointer was replaced with a 200mW laser module, the hexagonal mirror mount and case were 3D printed, and the mirrors were painstakingly aligned so the laser sweeps out a plane. An Arduino was added to control the motor and provide safety interlocks to make sure the laser fires only when the mirror is up to speed. The effect of the deep ruby red laser cutting through smoke is mesmerizing.

If laser sky is a little too one-dimensional for you, expand into two dimensions with this vector laser projector, and if monochrome isn’t your thing try an RGB vector projector.