DIY-erless Wii sensor bar
by Christopher Grant 
{ Nov 24th 2006 at 3:55PM }
We had some trouble with the Wii's wired sensor bar when playing on a projection television; even if the wire is long enough, you're left with the problem of having another wire to route around your furniture. Those without high-def projectors may scoff while explaining that this really isn't the sort of problem they would mind having but, nevertheless, we mind.
In the latest installment of DIY-erless -- our ongoing look at do-it-yourself wireless hacks -- we check out DoctaBu's guide for making your own wireless Wii sensor bar. Of course, we know that it's not really a "sensor" bar but a pair of infrared sources that the Wii-mote uses to triangulate the cursor's position. Using a perfboard, some IR LEDs, some wire, and four AA batteries, one can easily create their own projector-friendly Wii sensor bar.
Sure, you could always wait for that rumored retail solution, but wouldn't you rather make your own to match those homemade Wii component cables you've got rigged up. Check out a video of the process after the break.
[Thanks, Jonathan]
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Reader Comments (Page 1 of 1)
Wulkar @ Nov 24th 2006 4:03PM
Niice
Doomstalk @ Nov 24th 2006 4:55PM
But does it work? Will it mighty my Wii? Er, I mean nice one. Seriously, though, I wonder if there's any specific reason Nintendo included ten on the official unit. There must be some good reason, or they wouldn't waste their money on the materials.
Doomstalk @ Nov 24th 2006 5:03PM
Oh, and wouldn't it be simpler for everyone to just find an alternate way to power the official sensor bar? That eliminates any potential problems with imprecise LED placement, and would look a lot cleaner on top of your TV.
That Ninja @ Nov 24th 2006 5:04PM
Doomstalk, did you even watch the video? At the end it shows him using it.
Bunn @ Nov 24th 2006 5:08PM
Maybe for it to work in harsh enviroinments, I.E. Direct sunlight or next some weird lamps, the whole 10 are necessary. Most people won't need it, thoug
Matt @ Nov 24th 2006 5:08PM
More IR LEDs = more points to triangulate to = better sensitivity
Nill @ Nov 24th 2006 5:24PM
It's nice that they were able to do it, but a simple battery pack for the Nintendo sensor bar would make more sense.
rawker @ Nov 24th 2006 5:32PM
i have been meaning to make one of these ever since i saw the remote control video, i am just wondering has any body tried lengthening the distance between the leds, i am think that might improve acuracy on bigger tvs.
Doomstalk @ Nov 24th 2006 5:37PM
I did see him using it, but that doesn't mean much. It could work fine on early games, and then display problems as games start taking advantage of advanced features or more precise needs than Zelda. Or perhaps Matt is right, and the extra LEDs make it less sensitive to interference. Either way, it's obvious Nintendo put them in there for a good reason.
Paul Gandersman @ Nov 24th 2006 6:39PM
well i just built one but then two of the led's went out, and then a third went out, looks like i got ones that weren't powerful enough. plus they were supposed to be green and they showed up yellow, so i dont know if the problem is that the color is wrong or just that it needs more than two running at once, anyone know before i go buy some more powerful leds?
ubiquityman @ Nov 24th 2006 6:52PM
Just for the record, I believe it is NOT TRIANGULATION.
It's just seeing 2 dots.
So basically, if the Wii-mote sees the 2 dots to right, it knows it's pointing to the left (because it's a mirror image). If the 2 dots are close together (tiny image), it knows it's farther from the screen. If the 2 dots are farther apart (zoomed in), then it knows it's closer to the screen.
It's elegant, and simple, but it's not triangulation.
dr.melle @ Nov 24th 2006 7:12PM
has anyone thougt bout a simple mirror yet? aim you "sensor" bar at the mirror carefully aligned at your projector screen, and the ir should work just as good.
Benjamin @ Nov 24th 2006 7:15PM
Paul, what kind of LEDs are you using? They shouldn't be any color at all, they should be infrared LEDs. Infrared light is not visible to the naked eye (you can see the LEDs lit in videos, because the cameras are sensitive to it).
NinjaMoose @ Nov 24th 2006 7:49PM
Here's some tips if you want to build your own Wii sensor bar (sadly left out of the video.)
You can't just hook up LEDs directly to a battery the way you might hook up a light bulb. Each LED has a preferred voltage (referred to as "forward voltage"). Any less and it won't light up, and more and it's lifespan is greatly reduced and they will quickly burn out. To get around this problem, you need to put a resistor in series with the LEDs (referred to as a "current limiting resistor"). 100 ohms is a decent value for two LEDs in series. You can't leave out the resistor. It's vital for the life of the LEDs. Also, you can't put the LEDs in backwards, they only work in one direction. I usually look for a little notch at the base of the LED, which indicates which side is negative.
strider_mt2k @ Nov 24th 2006 8:36PM
Beautifully put!
MMX @ Nov 25th 2006 11:01AM
Maybe the sensor bar says to Wiimote the distance from the TV. If Wiimote "see" the two groups of LEDs on the bar, they will appear to be closer each other as you make the Wiimote far from the sensor bar (TV). Make sense for you? I don't have a Wii for testing...
Cahrdr @ Nov 25th 2006 12:14PM
What I did was buy four IR LEDs (276-143) and two single AA holders
(270-401) from Radioshack. I attached two LEDs to each battery holder
in parallel. I can adjust the distance between each self contained IR
emitter depending on the size of the TV. (I have a 13' wide front
projector and with approx three feet between them, I can stand about
15 feet back.) Simple, easy, and costs $12.Not having a soldering
iron handy, I used crimp on telephone connectors (64-3073) by
sticking two LED ends in one side and a battery lead in the other
then crimp with pliars. Be sure to either install a switch or pull
the battery out when not in use!
Bill @ Nov 26th 2006 8:47PM
Forgive me if this is an ignorant question, but does this IR system mean that line of site is required?
What of games like Excite Truck where your hand would block the sensor on the front?
If you point it backwards (imagine a full bat or racket swing) does it lose track until it comes back into view?
Rooster @ Nov 27th 2006 5:16AM
@ Bill,
I'm sure this is gonna get answered before me, but from I have seen, I believe Excite Truck merely relies on the accelerometer within the Wii-mote to steer the truck as opposed to pointing the correct direction. Very similar to the Sixaxis and how it might control in a racing game.
digitalrift @ Jun 20th 2009 8:06PM
ubiquityman:
Errrrr that IS triangulation though, isn't it?
The process of determining your location given two other points of known distance and position?
dave @ Feb 10th 2007 11:18PM
Hi,
i know I'm a little late in posting, but i have a few questions. I've just been watching the hl2 wiimote mod, and i would like to built a sensor bar for my 19" LCD monitor, but i also dont want to have to sit miles away from the monitor to have it work.
So, heres my queries, i hope someone might know the answer, and in turn, help anyone else looking to do this:
1st: Is there some way to make it accurate at closer ranges, i.e. space the leds specially, add more leds, or make it the actual length of my monitor.
2nd: Will adding more leds make it more sensitive. It would be especially cool if it could be really accurate...
Thanks for any help,
D