uiaccelerometer

I found the following piece of code in apple guidelines: - (void)accelerometer:(UIAccelerometer*)accelerometer didAccelerate:(UIAcceleration*)acceleration { //Use a basic low-pass filter to only keep the gravity in the accelerometer values accel[0] = acceleration.x * kFilteringFactor + accel[0] * (1.0 - kFilteringFactor); accel[1] = acceleration.y * kFilteringFactor + accel[1] * (1.0 - kFilteringFactor); accel[2] = acceleration.z * kFilteringFactor + accel[2] * (1.0 - kFilteringFactor); } What does it exactly do? What is this low-pass filter? Why do I have to apply it? Thank you in advance.

I want to scroll a scrollview based on the UIAccelerometer values. What is the best way to accomplish this? Initially I set the content offset to a value based on the accelerometer values I get. Then on each scrollViewDidEndAnimating , I again set the content offset based on the acceleromter values. I understand that setContentOffset actually scrolls the scrollview with a uniform velocity without any acceleration. However this mechanism seems to be very jerky in scrolling the scrollview. Any ideas will be appreciated. Thanks and Regards I did this once. sv is the scroll view. - (void

I am using the UIAccelerotmeterDelegate method accelerometer:didAccelerate: but recently that method has been deprecated in iOS 5.0. So what is the alternative way to get the accelerometer data? The documentation does not mention the alternative we are supposed to use. You should use the Core Motion framework (introduced in iOS 4.0) as a substitue. Create an instance of CMMotionManager and tell it to startAccelerometerUpdatesToQueue:withHandler: , passing it an NSOperationQueue and a block that will be executed on the specified queue whenever new accelerometer data is available. Antonio MG It

I want to create a simple app that draws a simple line on screen when I move my phone on the Y-axis from a start point to end point, for example from point a(0,0) to point b(0, 10) please help demo : John Fontaine You need to initialize the motion manager and then check motion.userAcceleration.y value for an appropriate acceleration value (measured in meters / second / second). In the example below I check for 0.05 which I've found is a fairly decent forward move of the phone. I also wait until the user slows down significantly (-Y value) before drawing. Adjusting the device

Still on the BigNerdRanch iOS Development book. In the Accelerometer chapter, they first implement accelerometer tracking but it's fairly jumpy. They then suggest to apply a low pass filter to it by changing the original code: - (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration { HypnosisView *hv = (HypnosisView *)[self view]; [hv setXShift:10.0 * [acceleration x]]; [hv setYShift:10.0 * [acceleration y]]; [hv setNeedsDisplay]; } to this: - (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {