Dear,
Just to inform those who are interested, TJ published his article in Circuit Cellar
http://bordelon.net/ezstar.html
I think they are interesting synergies to be done...
Marc
CIRCUITCELLAR
Issue #238 May 2010 — Measurement & Sensors
FEATURE ARTICLES
The FreeSpace IMU
A Quaternion-Based Algorithm for Attitude Estimation
by TJ Bordelon
An unmanned robotic vehicle requires a working inertial measurement unit (IMU), which outputs an estimation of the attitude, or orientation, of a vehicle in 3-D space. For attitude estimation, you need MEMS sensors (e.g., gyros, accelerometers, and magnetometers) and a sufficient algorithm to “fuse” them together. This article covers a simple quaternion-based algorithm for an IMU project. p. 14
Keywords: Inertial measurement unit, attitude, algorithm, quaternion, 3-D space, MEMs, dsPIC33FJ256GP506, gyro, accelerometer, MMA7260Q, AD7799, airplane, magnetometer, ADXRS150