What is in a Wii sensor bar, how does it work? and how to troubleshoot it.

Have you ever wondered what is under the hood of the Wii sensor bar and how it works?

We open it up to find out.

Opening it up

Opening the Wii sensor bar requires a tri-wing screwdriver, there are six small screws on the base of the sensor, two are hidden under foam pads on each end, these can be carefully lifted with a knife to reveal the screw.

After removing all of the screws the plastic backplate can be easily removed to access the insides of the sensor bar.

Inside a Wii sensor bar

Once inside the sensor bar you will find surprisingly little in the way of parts. The external grey wire runs into the back of the sensor bar and is connected to one of two integrated circuit (IC) boards with just two wires, a positive and negative.

The two ICs are connected by a ribbon cable and each have 5 LED lights and a resistor.

So there we have it, a power cable connected to two simple IC boards with LED lights and a resistor, there is nothing high tech about the Wii sensor bar.

The common myths (misunderstanding) of the sensor bar

It is commonly believed that the Wii sensor bar needs to be connected to the Wii console to transmit data to the Wii from your Wii controllers, this is not the case, the lead from the Wii to the sensor bar is a simple power lead, a plus and a minus, no data is transmitted.

It is infact the Wii remotes that transmit all of the users input data such as waving around the control and pressing a button, this is all done via bluetooth connectivity.

How does it work?

The Wii sensor bar is quite simply a bank of powered up LED lights, it transmits no data to either the console or the Wii controllers. The LED lights are used as a reference point for your Wii remote, the Wii remote picks up the light emitted from the sensor bar and uses it to work out the movement of your controller. Think of the wii sensor as a light house or lit up runway directing boats or aircrafts towards a docking or landing area, the lights from the Wii sensor allow your Wii remote to work out the direction of its movement in order to control the game characters or cursor onscreen.

Because the sensor bar is simply two light reference points it is possible to use two candles instead as seen on places like youtube, although the actual performance and safety is questionable and not recommended.

My Wii controllers do not appear to be working, what could be wrong?

Providing that the leds inside your sensor bar are lit up there is not much else that can go wrong with a Wii sensor bar, instead you should turn your attention to the Wii remotes.

As previously mentioned the Wii remotes work off bluetooth, so you may need to resync your controllers from time to time, especially when they have not been used for a while or batteries have been replaced. You can sync a controller to the Wii by pressing the red sync button on the back of the Wii remote (under the battery cover on some models) and the red button on the Wii console found on the front under the SD card door (underneath the CD drive).