Cyclops' Den
Media Wiimote

While the Wiimote contains an innovative new way of playing, with it sensing movement, it isn't as good as it seems. Unfortunately, it can be quite inaccurate without the small strip which is called the Sensor Bar. This bar is actually quite simple. It contains 2 groups of about 5 Infra Red LED's, constantly transmitting. A small camera in the front of the Wiimote uses these Infra Red lights as another point of reference. So, it reads the Up/Down, Left/Right, Forward/Backwards, and Relative to IR lights movement to work out exactly where it is going. These 4 working together actually allow it to be insanely accurate (as you will notice while playing Wii games).

To get the same level of accuracy on a computer, you will need a Sensor Bar of your own. And lucky, there are instructions out there on how to make one. Like these ones from the Forums. Naturally, I want good movement, so I decided to put together one of my own.

As I mentioned, this remote will be used at my TV. Which, you can guess, will be a distance from a USB port (don't count my Playstation 2 USB ports). But I still wanted ease of use near a computer. So, I decided to go with a dual use setup. A USB cable (which should run off any USB port on a computer, which should output 5v 600ma) paired with a small adaptor that can turn a standard transformer output into USB power. I could only get a 4.5v transformer (without paying twice as much for a multi-voltage one), but the small change in voltage shouldn't matter. If it does, I will replace it with a different one. Anyway, onto the parts list...

What I came into this with. At least half the plastic there wont be used.

Parts for my Home-Built Sensor Bar, and Power Supply to match.The contents of Mr. Bag in the above picture.
NOTE: Prices and links are to an Australian store, which is similar to Radio Shack.

Got to love those Crap-tastic picture!

How did I decide on some of those parts? Since I decided I would be working off 5V USB some of the time, I was able to use this calculator to work it out. It told me I needed 51ohms between the Power and each parallel LED circut. Here is a diagram showing how I plan on hooking it up...
You too can become a master of Macromedia Fireworks, and make profesional pictures like this!         Even simpler.....
Two circuits in parallel, each containing 2 resistors (totaling 51ohm) and 2 IR LEDs. The Data wires on the USB Plug are ignored. Then, for the Sockets, its quite straight forward. USB +5 to the Center pin, which should hopefully be Positive.I might do some searching, but im pretty sure thats how they are normally done.

The plan is to cut the USB Extension cable near the Socket End, and use the rest of the cable as the cable for my Sensor Bar. The Socket will then be wired into the DC Socket, to be used as an adaptor. Some things to note:

  • I didnt get a 3m USB extension cable because that was about $20 more and It would only improve the chances of the USB cable reaching with little effort. I have plenty of extenstion cables (that I use, which is why no-cutty them) so if its just shot I can use those.
  • As mentioned above, I could have got a multi-voltage power supply that did exactly 5V. But it was much more expensive, and I couldn't be bothered. The .5V shouldn't effect it too much. If it does, I will upgrade the adaptor.
  • I am cutting it close (read: Exact) when it comes to the Ohms before each set of Leds. I could have given it some more headroom (with, say, 15 Ohm resistors) but I figured that most of the time it would be running from the 4.5, so it wouldn't matter too much. When it brakes down too quickly after running on USB, feel free to laugh at me for assuming. But not a second before.
  • I am planning on picking up Panel Mounts for my LEDs, to make it look a tad professional. *snicker*

The first thing for me to do was to check out the USB cable. So I took out my work knife/pair of scissors, Cut it about 10cm from the socket end, and striped it back a bit.
Motion Blur - All good photos have them.
Hmm... I was expecting Red (5V), Green (Data +), White (Data -) and Black (Ground). That silver one to the side is the protective shielding all wrapped up together. Lets check this out....
There is a clip on my lead... 5.07V DC. You liar! You said it was 5V!
Ok. Looks like Gray is the ground in this cable. Wonder what the shielding plugs into...
And now there is a clip on my sheath... With 100% more acidental reflection to proove its another picture.
Looks like that plugs into the ground as well. Thats good.
In my cable, Im not going to need the Green or White (Data) leeds, so I will likly just terminate them.

What about the other end..... Oh crap. The cable is too wide to fit into the cover of the DC socket. And I cant make it fit. I think I will be doing some sneaky Heatshrinking with that to make it work. Oh well, thats something for later... *puts USB cable aside*

Next I decided to check the parts, before actually wiring them up, or even putting them in the case. After half an hour of bending thin leads that dig into soft fingers, linking together said thin leads, connecting wires to connect to the USB cable, fixing the thin leads, connecting the USB cable, fixing the thin leads, fixing the wires, fixing the thin leads, and fixing the wires one last time, I was ready to test the connection.... I had all of 5cm to move - otherwise I would send the entire connections falling off (already nearly did it once).

Click and.... I cant see anything... Oh wait, its IR light....
My hairy wrist is in there, because I couldnt move it. Unless I wanted a lap full of IR Leds.
There we go. The light blue glow of invisible light. And without the back light...
Shine... shine... shine...
Just to be sure, lets *click* unplug it
A perfect picture of nothingness!
So the circut is all working. The power is flowing around, and the LEDs are lighting up. Guess im ready to get it all ready.


Thats as far as I have got so far. Taking my tim putting it all together... Plus, I want to grab more wire. I think I will need it.

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