Cheap Compact Battery-Operated Programmable Outdoor Laser Projector

[Throw333]

Hi everyone,

I want to create laser shows for my country property. I want to be able to project onto a building from about 30-50m away. I want the projector to be chargeable/ battery option and as cheap as possible - pref under $100. I want it to be programmable - i.e. I want to be able to create my own messages and animations. Also, it would be good if it was compact.

Is there a way I can do this using electronic parts and circuitry - e.g. Arduino or a Raspberry Pi? Thanks.

Thanks for any tips!

 

[rjenkinsgb]

The only two choices I know of to do anything like that are a straightforward video projector, or a laser scanner.
I don't think you would ever get a projector to work over that distance, at a reasonable cost.

You could just about build a scanner for that cost - there are kits with the critical parts on ebay.
example:
**broken link removed**
(Search "laser light show scanner" for more examples).

To "draw" with a laser, you need something like that, a mechanical deflection or scanning system, to control the beam direction - there is no way around it.


You can get complete scanner units for not much more, but they appear to be basic random pattern type effects rather than high speed scanners that can "draw" complex images.

The "PPS" rating of the scanner galvanometers relates to how fast they can move, so how complex an image can be drawn and updated - the higher the number, the faster they respond (and the more expensive they are likely to be).

It appears you have to add your own laser to the kit parts, those are just the beam direction control.

Or things like this, ready made but just random effects, by the look of it:
**broken link removed**

 

[gophert]

The big thing in the miniaturization of scanning Lidar is to use a mirror on a gimbal that is driven by a pair of voice coils powered by a DAC with some calibration.
Otherwise, there was a setup at Virginia Beach boardwalk a few years ago with a spinning mirrorized octagon about a 1/4" thick. The laser it the perimeter of the spinning octagon for horizonal raster and a voice coil for vertical positioning. It was a pretty high power green laser. You'll have to calculate the luminous flux you want across your barn to make sure you can see it from a distance. Moon light is about 1 lumen/sq meter so you'll want some higher level of brightness to overcome that base light for a decent contrast ratio.

a point of light intensity gets diluted quickly as you scan a bigger and bigger area with finer and finer resolution.

finally, the higher power your laser is, the higher efficiency mirror you will need to scan/raster if you use an indirect rastering method. High efficiency is needed with higher power lasers to prevent heating the mirror.

Good luck

 

[Throw333]

Wow, thanks heaps for that info gophert and rjenkinsgb. That is very helpful - means a lot to me. Cheers.