7 Color Light Pen

This is my first instructable in a while. I've been busy busy busy with all sorts of things, some of which probably would have made good instructables, but few of which I documented very thoroughly. This instructable has been floating around half completed for a long time, and I figured it was time to just bite the bullet and post it.

I owe a debt to unklstuart for this instructable, which inspired me. I thought of making some of these light pens a while ago, but I am unfortunately not much of an artist. Still, the pens were awesome and I thought I'd like to have a set, if just to play around with. However, my camera only takes a maximum of 16 seconds per exposure, which really limits the ammount of drawing you can do. Then I hit upon the idea of making one pen that can do many colors!

So, I built the pen, and had my suspicions that I am a very poor artist--especially at high speeds--confirmed. Ever since, I've been trying to find someone who is an artist (like my brother) who could draw me a few nice looking pictures with this doohickey. I got impatient, and a while back I posted this instructable. It wasn't very popular, probably because it seemed a bit half baked, which it was. I wanted to post something about this light pen, but I was still having trouble finding someone to draw some pretty pictures to illustrate this intructable.

Well, all that is behind me now. I've finally decided it's time to post this thing and get it over with, even if all I have to show are my low quality 16 second scribbles.

Here it is in all of it's glory, the 7 Color Light Pen!

***UPDATE 5/4/10:  If you post your own light pen drawings in the comments below, I'll send you a patch!***

Step 1 Gather parts

First and foremost, you're going to need an RGB LED with 3 anodes and a common cathode (or vice versa). You can either buy one, or make one from materials you probably already have on hand. Here's my RGB LED instructable if you want to make one of your own.

Also, you will need:
3 pushbutton switches
1 9-volt battery and connector
Some sort of case for the pen (I used the housing for an old microphone)
3 resistors (I used 2.2k for blue, 1k for green, and 330 for red)
A little extra wire
Hot glue
Foam rubber (for padding)
Electrical tape

Comments

[legendx]

how could you draw that fast
?

[depotdevoid]

Very poorly! It's really hard to draw anything in 16 seconds!

[legendx]

so its kind of impossible

[depotdevoid]

Well, it's really difficult with my current camera. I'd like to upgrade to one with better manual controls for this and for astral photography, but those are kinda pricey.

[legendx]

ok

[platinum97]

Is there a way I can make this reeeaaallly simple without paying 4 it. And can I make it so that I don't need a camera to show my drawings with the pen. It will just show in mid air and a way I can make it with no soldering?

[depotdevoid]

platinum, I suppose if you could find all of the parts you could probably make this for free, it would just be a matter of finding electronics to harvest from. If you just twisted all the leads together and used a lot of tape you could probably make this without soldering, but it would be pretty flimsy. However, you have to have a camera. What you are asking for here is magic, which unfortunately isn't real. Light does not just hang in midair, and if it did you wouldn't be able to see it since the light wouldn't be entering your eyes. Light has to be emitted from something, it doesn't stay put. Don't they teach this stuff in science class?

[platinum97]

Well...um they do...but u know... people think of so many things these days, wow that was a dumb question I asked >=( err. Well thank u for your help

[depotdevoid]

Sorry if I came across a little grumpy there, I've been reading a lot about the declining standards of science education and literacy in America. Did you know that 40% of Americans think dinosaurs and humans lived at the same time? And 55% of them think that atoms are smaller than electrons? Man, that's depressing.

[Murf]

WOW.. that is depressing! As a Ph.D. student in the sciences who is a teaching assistant and does outreach programs with 5th graders and 11th and 12th graders, I have definately seen a decline, but didn't realize it was getting that bad!!

[depotdevoid]

Yeah, it's ugly.  I don't recall the exact stats off the top of my head, but the numbers for how many people believe the Earth is 6000 years old and how many don't know how long it takes the Earth to orbit the sun are pretty scary, too.  Hell, even 30% of high school science teachers thing creationism should be taught alongside the theory of evolution.

I don't know what to do about it.  The only person I know who doesn't laugh at me when get upset about this sort of thing is my girlfriend, and I think she's just humoring me.

[platinum97]

O its ok. The declining standards of science education is correct, they have. I've noticed we learned a lot of things last year that were pretty interesting and more than what the class expected. This year is deeper thinking of what happens when we throw trash away in the garbage. We think its the end of it when we throw it away, but its really not, going through all these cycles. Now I watch wat I do, and how I can help the enviroment

[platinum97]

Sorry I guess I like this so much that I want it easy >=(

[rewena]

this is a cool idea i know i wouldn't be patient either. i want too try doining this but i dont know were to get a RGB LED from i cant make one cause i dont have these materials. can u tell me were to buy one on your instructable?

[depotdevoid]

Well, a quick google search for "RGB LED" came up with these results:

http://www.sparkfun.com/commerce/product_info.php?products_id=105
http://www.superbrightleds.com/TriColor%20LED.htm
http://www.goldmine-elec-products.com/prodinfo.asp?number=G16706&variation=

But you could make one with parts from the dollar store . . .

[rewena]

thanks for all the help and research i will try your ideas. thanks im sort of new so thanks for helping

[depotdevoid]

No prob Rewena, good luck on it, and I'd love to see some pictures if you end up making one of these!

[rewena]

thanks for the help i will try that

[makerfaker1]

if i give u my address will u make me one so i have reference to go by i would pay u but i don't have any money right now and if u do i really will apreachate it u never know i might make something for u in return but if u don't that will be fine to thank u

[Ronanoke]

u rly got 2 use ur brain b4 u make a post because if u can't offer compensashun and/or r 2 lazy 2 do it urself then its ur prob. My txtspk is really deteriorating. Not sure if that's a bad thing.

[depotdevoid]

Oh, that's good. I never responded to this guy, since I'm a bit of a grammar nazi and can't stand txtspk. I don't go so far as to correct people on "There, their, and they're," but I feel that if you can't take the time to type "You," then I don't have the time to respond. Thanks for the laugh, and replying to makerfaker1 in the language he speaks!

[Ronanoke]

No problem! :)

[Ronanoke]

This is really interesting, apart from the horrible enclosure (although that's hardly a technical part of it). Hypothetically, how hard would it be to run this on, say, AA batteries, or a watch battery?

[depotdevoid]

Oh, it should work fine with AA's or watch batteries. I use 9-volts where I can because they're more compact than the 3 AA's you'd need and they last longer than watch batteries.

[Ronanoke]

Cool! Thanks!

[sjs229]

how do you switch colors?

[depotdevoid]

Oh wow, how did i forget that? Thanks sjs229, I've added that to step 4!

[sjs229]

good!

[frollard]

Great little project!

[depotdevoid]

Thanks frollard, I'm glad you liked it!