Really simple & cheap light-bar, powered and controlled from pc ( over lpt port ).

It will cost you something about $10-20 to build this
( I had the plexi and lpt cable for free, so I only paid $3 for led torch and $3 for nuts and bolts )

= killer raito fun for money

video in action

video from testing

In real world is even better looking because eyes are slower than digital camera, so it is glowing nicely.

Step 1: What we need

8 colorful pieces of plexi-glass ( or you can use same color, they just need to be discrete, I used 10 x 7 x 0.5 cm )
2 large pieces of transparent plexi-glass ( I used 56 x 12 x 0.3 cm )
8 leds ( I ripped them off from one $3 led torch, basically use wide angle! (with 15 or 45 degree LEDs it is looking bad, use as wide as possible ), high power, white LEDs )
bolts and nuts
black spray
parallel port connector ( I used one from old printer )
sandpapers ( 200 & 400 )

I got the small pieces actually as testing samples from a company making plexi (plexiglass.de), they gave them to me for free. Big thanks for them :-)
Can you make it Bluetooth so you can connect it to a phone 
If I use this usb converter. He will work?
why not making it into a usb instead of the other cable because many computers don't have that connection anymore?
can you use an ethernet cable instead of the parallel port
It would be really cool if you made it so the LED's went on when you touched the individual plates!
yeah, or make it something like this :) http://www.youtube.com/watch?v=6rCfhF-fNb4
is there a way to use 10 leds?
i made one aswell:<br><br>http://www.youtube.com/watch?v=c3PsrWNzZPI
do want!
Hey quick question, I believe I've set mine up correctly, but 2 of the 8 LED's are permantly lit up. Any suggestions?
go to the settings for those two lights, and make sure the first slider isnt at 0. i had the same problem, and all i did was put them at 1.
you mean even if you start program or winamp plugin? 6 is working right and 2 are lit up all the time? actually never had that problem, there are random blinking during pc boot and after that it usually stays all lit up until I started program or plugin...
2 lights are lit up constantly. it would be approx. the middle 2. so weird. just wondering now if it might be windows 7...
has anyone made one with all one color? im interested to see if it would look good or just blenf into a big.. blob. idk, i dont want alot of colors so i was thinking red blue red blue red blue ya know. but thnx man this looks great still not sure how to use the programs tho im not to goos at this stuff
not red blue but this also looks good. made it yesterday. very awesome instructable. = )
Is there anyway to hook this up to a mac computer?
wt will happen when we use extra LED's instead of resistors ???<br>like making a series of 3 LED's and connecting it to the pin ???<br>
I like this instructable sooo much i made my own version! And Made an instructable about it! :D http://www.instructables.com/id/LPT-BOX/
closed grit or open grit sand paper?
Think I will try that. http://www.instructables.com/id/No-solder-parallel-port-break-out/
could you use clear acrylic sheets with different colored LED's to get the same affect?
probably yes, but diferent colors of leds means diferent resistor for each led to make sure they shine equaly and dont get burned from overvoltage.. and that acrylic still has to be &quot;frosted/translucent&quot; not just clear/transparent (if you know what I mean )
I know how to frost acrylic. Does it really matter if i use different resistors?
try it and let us konw :)
I actually don't have a port on my computer for the computer connection so I'm going to do a static version with rgb leds
where could you buy the colored plexi glass
Check this <a href="http://www.tapplastics.com/shop/product.php?pid=341&amp;" rel="nofollow">http://www.tapplastics.com/shop/product.php?pid=341&amp;</a><br />
could i use an USB cord
how to connect this to the winamp..? to show the light show music..
download winamp plugin... just read the text man
Is the parallel port connector male or female? Thanks.
its female on the board, so you will need a male connector
Would it be possible to use a usb Parallel port adapter with this setup?
a usb port would require an extra piece, like a micro-controller...a Parallel port would be possible though with a similar set up (i am no expert in electricity nor I/0 ports so don't take my word as religion )
alright, i just ask because i only have usb ports on my laptop and I know there are a few companies that sell usb to 25 pin dsub parallels adapters
ahh, i would try the convertor...see what you can do
It would be more fun to create your own software <sup>.</sup> . Try using Visual Basic or Delphi.<br/>
If you're into python there's an extension called pyparallel that might help. There's a great example code here: <a rel="nofollow" href="http://pyserial.wiki.sourceforge.net/pyParallel">http://pyserial.wiki.sourceforge.net/pyParallel</a><br/>
Couldn't agree more. I'd like to see it in plain old C though...
This is my first project so maybe this goes without saying but I was wondering what size wire is used for the connection between the lpt cable and LEDs and how do you terminate at both the port and LED splice points?
It is a good idea to put in a resistor even if the supply voltage matches the rated voltage of the LED. It is there simply to limit current, so something like a 1 Ohm resistor will protect your LED's.
The resistor is there to protect the parallel port, not the LEDs. A new motherboard is a bit more expensive than a few LEDs, and you can easily kill your parallel port (and the motherboard, if it's onboard) by drawing too much current.
yea, you are right, fixed
ok so i made mine with 4 red 4 blue and it looks great. Only problem is i got a new computer used my old graphics card and harddrive in my new computer. the led's blink when starting up but when i run the LLC or any other program it doesnt run the lights. anythoughts on what to do? thnx
How many bolts and nuts? and does size of the bilts and nuts matter?
basicly I used 2 for each square on top to hold it leveled, and the same amount at the bottom to match visual, size is M4. But you can go bigger/ smaller, depends on taste :-)
So, with this project i can control 23 LEDs?
Yes you can control 23 LED's but this will require some other special made software to use the 8 D pins on the LPT port , and also you would need some shift register chips .
my LEDs just stay on, the program won't work. i need some help.
i want to make one of these sooo bad but my laptop doesnt have a printer port, is there any way to make this thing controllable over usb or something like that?

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