Question

I remember seeing the code for a Highpass filter a few days back somewhere in the samples, however I can’t find it anywhere now! Could someone remember me where the Highpass filter implementation code was?

Or better yet post the algorithm?

Thanks!

Answer 1

From the idevkit.com forums:

#define kFilteringFactor 0.1 static UIAccelerationValue rollingX=0, rollingY=0, rollingZ=0;   - (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {      // Calculate low pass values      rollingX = (acceleration.x * kFilteringFactor) + (rollingX * (1.0 - kFilteringFactor));     rollingY = (acceleration.y * kFilteringFactor) + (rollingY * (1.0 - kFilteringFactor));     rollingZ = (acceleration.z * kFilteringFactor) + (rollingZ * (1.0 - kFilteringFactor));      // Subtract the low-pass value from the current value to get a simplified high-pass filter      float accelX = acceleration.x - rollingX;     float accelY = acceleration.y - rollingY;     float accelZ = acceleration.z - rollingZ;      // Use the acceleration data.  }