Arduino Laser Show with Full XY Control

This project uses an Arduino and some cheap audio speakers to create a real laser show with full X and Y axis control.

The included source code lets you easily draw text and even simple pictures!

View the demo video to get an idea of what this project can do.

You should be able to get most components locally (besides the Arduino).

Assuming you already have an Arduino - expect to spend roughly $35 on this project.

If you can upload a program to an Arduino and solder - you can probably build this project in an afternoon.

Users who have built this project:
mattbeowulf - http://www.youtube.com/watch?v=AnIoWZpEWk8
minhenes (using "real" galvos) - http://www.youtube.com/watch?v=BmYg3O4hlMg
hydronics - http://www.youtube.com/watch?v=5Q3nJLA2t18
benhgd - http://www.youtube.com/watch?v=K23-ThlCZEc
(Post a comment with your link - and I'll add yours to this list)

Step 1 A Bit About Laser Shows

Most laser shows use galvonometers (the little boxes in the picture) or "galvos"  to aim their mirrors.

Galvonometers are electromechanical devices that rotate to different angles based on how much voltage they are provided.

A minimum of two galvos are used - one for "X" (horizontal) control and one for "Y" (vertical control).

The laser show's controlling electronics quickly adjusts galvo voltages, and turns the laser on and off - moving it around so quickly that it appears to create a persistent image.

Commercially available galvos can move to up to 50,000 different points each second.

Galvos tend to be expensive - so we'll be making our own out of audio speakers!

Comments

[hydronics]

Hey, I basically copied your instructable but put it in a portable container to make a strategic gerilla propaganda 'box'

http://www.instructables.com/id/Guerilla-Laser/

Going forward I would recommend using a stronger laser... This would allow you to hit a building or billboard at a mysterious distance... I tried to buy a stronger, $14 green laser from China but the china laser circuit did not allow cycling ON/OFF at quick rate like the cheap laser is used...(this is called blanking in the laser light show industry) You could rewrite the code to be more cursive in nature and less ON/OFF dependent... It would be fun to play with the programming in such a way and easy for a beginner... its all cartesian coordinates... that means easy!

thanks again for all the hours of dinking around....

[nothinglabs]

that's awesome!!!

had similar problems trying to use a green laser too.

suspect it's possible to get it a green laser working with some tweaking - the driver circuits are a bit more involved than is intuitive... (think they tend to involve temperature feedback and such).

[deeaa]

Hi Rich

i'm planning to make this with microcontroller as i don't have Arduino, so i need to know some details about

1- speakers control pulse
i think it will vibrate to a specified level with the pulse from oscilloscope image, I mean not smoothly or variable level like saw-tooth for instance.

2- is it vector drawing or bitmap

3- could it be like this http://www.electronixandmore.com/project/14.html ,i mean red & white only not even like gray scale

[nothinglabs]

the code is for arduino - but is largely native Atmel code. You could use an "naked" Atmega328 for this project with very few changes.

the project outputs a PWM pulse (see step 31) - which effectively drives the speaker in analog.

the system draws in vector.

I suspect the system as I've documented is much too slow to render tv-like images as described in that project!

good luck / have fun!

[showup]

Very nice one. I will build one. Thanks for the detailed instructable.

[henridutoit]

hello,

can you send me please the full code for my arduino ?


henri,

[nothinglabs]

should be attached to step 26 - let me know if you have any trouble with it.

Good luck!

-Rich

[henridutoit]

hello rich,


i have a error when i program my arduino ,

sketch_mar21a.cpp: In function 'void loop()':
sketch_mar21a:6: error: 'demo' was not declared in this scope
sketch_mar21a.cpp: At global scope:
sketch_mar21a:10: error: 'The' does not name a type


bye,


henri
can you send me the FULL program to put on my arduino ?
please ?


thanks .

[nothinglabs]

I just verified that the .zip file attached to step 26 compiles fine.

From your error - it sounds like you might be just using the code listed in this step - which isn't complete. It's just showing how you can modify the code that's included in step 26.

I would redownload the code attached to step 26 - and try it again.

If that doesn't work - I'd make sure you have the latest Arduino software.

Let me know if this helps or not.

Good luck!

-Rich

[henridutoit]

hello,


can you send me the FULL PROGRAM FOR MY ARDUINO PLEASE ?


thanks you


henri,

[northconnor]

Henri, look in step 26 of this instructable. There is the FULL PROGRAM FOR YOUR ARDUINO. attached in a zip file, not just the text shown in step 30.

[mattadamsnet]

:) Love it,

I WONDER IF HE GOT THE CLUE !?!?!?

The .pde in the .zip on step 26 complies with 0 errors using arduino IDE v21

Very Nice Instructable,
Keep up the nice work.

Matt

[robot797]

i cant get it clear
if i put my finer on the speaker clear as day
without i cant adjust it

halp

[nothinglabs]

as I mentioned in my other post - sounds like you're speakers may not be the best for this project.

I've done some testing - and found the following speakers work great for $0.97 (+ shipping):
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-012
(it's a close-out - so they won't last forever)

These $7.50 speakers have not been tested - but should probably work well based on their specs:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-065
(if you end up buying a set - let me know how they work!)

[robot797]

mmm to bad they wont ship it unless i order for 50$ XD

[nothinglabs]

the order I did was much smaller than that (think like $18 with shipping) - had no probs. is that maybe to get free shipping?

[robot797]

i live in holland

they have an internatial limet

[nothinglabs]

I fought with this issue a bunch. Did a bunch of things to try to "emulate" the effect of my finger - but didn't have a lot of luck.

Biggest thing that helps is using speakers of the right quality / size.

How big are the speakers you're using? About 5" is optimal. Bigger is -not- better.

What is there power handling? More is better.

Do the have nice big magnets?

Also - are the resistors installed as described? They help with this.

You can also try drawing smaller by setting the move_scale variable smaller.

Slower drawing can also help - try setting exp_move to something higher like 6 or higher.

hope this helps!

-Rich

[Fridg]

Awesome Instructable man loved this one! i got most of it built just waiting on transistors, but while i wait iv been working with simple sound waves along with a few blinking red lasers turning on and off every 5milliseconds.

http://www.youtube.com/watch?v=NMo4eqPFpxc

[nothinglabs]

glad you like it - good luck with the build.

I used this project to do a laser countdown clock for a new years eve party - was a big hit.

nice laser show with the sound waves!

-Rich

[wildstrs]

for power supply what about using a battery eliminator , guess its simpler that way ????

[nothinglabs]

think you'll definitely want a power supply close to the one in the parts list.

this project has moderately beefy power requirements.

good luck!

-Rich

[Eternal_Tristan]

What are the capacitors for you in your schematic? I assumed at first they they were for smoothing out the PWM signal, but I read on the last page of your instructable that the signal is still a high frequency pulse shape at the speakers. So they are not smoothing out the PWM signal. What are they for?

[nothinglabs]

caps are just for smoothing out input power.

project will work without them - but they help improve the image quality significantly.

[janisalnis]

Hi!
Your Instructable was so impressive that I could not resist copying it. Here is the result:
http://youtu.be/BmYg3O4hlMg

First I used galvos from old electrocardiograph, but they were ope loop and had bad hysteresis. Galvos from Ebay were much better. Can run your code at max speed.
Description of my box is here

http://barbara320.gotdns.com/alnis/elektronika/Arduino%20lasershow.pdf

[nothinglabs]

that's awesome!

I had always wondered how it would look with real galvos...

-Rich

[mortaldoom780]

This is truly impressive; very clever stand-in for a galvo!

I think I am dead set on building one, but first, I'm curious what can be done to improve:
1) The KPPS rating (the rating for this guy must be pretty slow) and
2) Image quality (i.e. your text draw functions would generate more refined, less-jagged letters)

I read up on the basic theory behind galvanometers in the realm of laser light shows, and I'm wondering if using a high-resolution DAC instead of PWM would help one of the above drawbacks?

Again, very cool.

[nothinglabs]

I'm not sure - but my suspicion is that the mechanical limitations of the speaker are the major limiting factor.

I did at one point put the output on a oscilliscope (pwm smoothed out through capacitors) - and the rendering was very clean compared to the speakers.

I did try driving the transistors via analog - didn't get good results - but I wouldn't call it definitive (suspect the transistors weren't happy being driven at less than full power)

glad you like the project - good luck with the build!

[hydronics]

Nice job. a lot of fun putting this together. It was my first arduino project and worked great except I initially put both transistors on the same heat sink which skewed my image to a gobly gook 45 degrees.. whoops...

http://www.youtube.com/watch?v=5Q3nJLA2t18

[nothinglabs]

nice build! thanks for sharing the video!

I noticed you left your speakers in the cabinets - I've found with some speakers this helps - and others it doesn't.

It seems taking the speakers out of the cabinets gives a larger image - at expense of image quality. Also depends if the speaker cabinet is "vented" or not (from my testing - plugging up the bass port made a difference in performance - but I forget the exact effect at this point).

I can't tell you how many times I've run into the same issue with that kind of transistor having the case connected to one of the pins... makes heatsinking a bunch of them a pain in the butt.

-Rich

[Rocketman1954]

Hello Rich,
I can,t open your program for the arduino for some reason. Is this a PDE file? Windows on my computer does not reconize it.
Regards
Larry

[nothinglabs]

Yes - it's a zipped PDE file.

I'd open the file - and copy out the folder / contained PDE - and then open directly with Arduino.

-Rich

[ookid]

One question, couldn't one theoretically make this with much smaller speakers as long as the unit was father out from the display surface? I just think that it might be easier to implement this without the monster sub woofer speakers. Anyway, It is a wonderful and well written instructable.

[nothinglabs]

Thanks!

Yes - I have tested with smaller speakers. I got one set of 3" 'satellite' speakers working fairly well - but the image was -really- small (maybe 5"x5" at 20 feet).

I was leaving the speakers in their enclosures - which resulted in fairly good control. When I took the speakers out of their enclosures - the image was larger - but really sloppy.

that said - my speaker selection has been influenced by whats in stock at the thrift store - so maybe I just never tested with smaller speakers of good enough quality.

if you end up experimenting with this - let me know how it goes!

[ookid]

I finally got around to making this with some apple speakers. I haven't attached my arduino up to this yet to test it out but I did play some music and the patterns seem to be repeatable. I also played some square, sin, and triangle waves through them with a tone generator and it out puts some pretty awesome effects. You are right about the size though, at 50ft the max radius is only around 2ft max.

[nothinglabs]

cool - ya, there's definitely a trade-off between having decent control of the laser and image size.

haven't played around just doing "patterns" generated by the arduino - that might be a fun area to explore.

let me know if you get things hooked up to the arduino and shoot some video. I'm adding links to other people's version of this project to the main description page.

-Rich

[mattbeowulf]

This is great! Well done, sir. I just finished my build and am excited to work the bugs out. I want to ask though if the author or anybody else knows about the feasibility of canceling out the noise of the speakers as they play the show. Could the Arduino send the inverted bit pattern to a second pair of speakers (just for the sounds of course) to cancel or at least tone down the noise? I don't really know anything about noise-cancellation, so not sure if its a realistic possibility in this application.

Matt

[nothinglabs]

Congrats - you're the first person I've heard from who has completed the build!

Yes - it can get kind of noisy! Most of the noise is relatively low frequency - so I'd think cancelling it with a second set of speakers might work. It can't hurt to try.

I think just connecting the cancelling speakers up to the same leads backwards might be a good place to start.

How is it working for you so far?

Let me know if you have any other questions - happy to help troubleshoot / etc.

[rschlagle]

Hi, awesome build. threw it together in just over an hour. (lots of stuff in "the bin" so no trips to the store)

I'm planning on removing most of the material of the speaker cone, thus not moving any air and no (mostly) sound.

I'll let you know if it works so you don't have to ruin your speakers.

If all goes well, green laser sky show for the fourth of July.

Again, thanks.

[mattbeowulf]

Hadn't seen your post until i got around to working out the bugs in mine -- anything to report on your end? I like the idea of simply removing cone material rather than trying to noise-cancel with another set of reversed-phase speakers...