The sensor bar has IR LEDs inside of it. The wii knows the pointer location and roll by tracking these two LED points with an IR filtered camera inside the wii-remote.
Normal LEDs have a viewing angle of about 45 degress, meaing you can be right in front of them or up to 23 degress to the direct left or right. Outside of that range, the wii pointer will start to glitch. This is what I wanted to get rid of. I also wanted higher power so I could stand farther away. So the normal viewing angle is like this
And I wanted a wider viewing angle like thisSo I decided to build my new sensor bar with multiple LEDs on each side, pointing out in different directions, thereby expanding the viewing angle of the wii remote camera.
Here's the simple schematic. I used a 5V wall adapter, but soon I'll be hooking it up so it will turn on wirelessly with the Wii. That step is pretty low on the priority list right now, though.
I used some little hobby PLCs from Radio Shack and colored them black with a marker. Then I used 2 sided mounting tape to attach them to the projector screen case. I wanted them at the top of the screen because I've noticed I get wrist cramps with them at the bottom.
I left the LEDs sticking out about 1/2" from the board, this way I could point them around to find the optimized angles for all the play positions in the room.