Tuesday, November 27, 2007

The Wiimote IMU

I've always been interested in inertial measurement units. I recently looked at the Wii Zapper frame and thought that we now have a 5.5 axis IMU. The Wiimote has a 3 axis accelerometer. The nunchuck has another 3 axis accelerometer. Now, if you have six axes of accellerometers that are arranged right, you can get good rotational data from the accelerometers. Unfortunately, this isn't perfect in this setup. You get a good pitch and yaw, but no roll information. This can be estimated out when the unit is roughly at standstill by determining where gravity is. So, if you figure out your distance between the two accellerometers in the Zapper, you have a rigid 5 axis IMU with a wireless connection. No phystical hardware hacking required (other than maybe for measureing the actual center to center position of the accelerometers)

Pretty cool, no?

2 comments:

Mike said...

Can you disasemble and reassemble without modifying the circutry to get better positioning?

Tobias said...

Do you have any idea on how to implement this? Things to consider etc?

If so i'm at tobias dawt knutsson at gmail dawt com.