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2014/10/15 ¤U¤È 10:05:09

iphone Programming Glossary: cmdevicemotion

Why am I getting 0 degrees from magneticField property the whole time?

http://stackoverflow.com/questions/11711646/why-am-i-getting-0-degrees-from-magneticfield-property-the-whole-time

wrong CMMotionManager motionManager motionManager CMMotionManager alloc init motionManager startDeviceMotionUpdates CMDeviceMotion deviceMotion deviceMotion CMDeviceMotion alloc init while self.stopButtonPressed double x motionManager.deviceMotion.magneticField.field.x.. CMMotionManager alloc init motionManager startDeviceMotionUpdates CMDeviceMotion deviceMotion deviceMotion CMDeviceMotion alloc init while self.stopButtonPressed double x motionManager.deviceMotion.magneticField.field.x double y motionManager.deviceMotion.magneticField.field.y.. something similar here. Edit From the docs The latest sample of device motion data. read only @property readonly CMDeviceMotion deviceMotion Discussion If no device motion data is available the value of this property is nil. An application that is..

Safe update interval for startDeviceMotionUpdatesToQueue:withHandler:?

http://stackoverflow.com/questions/11797857/safe-update-interval-for-startdevicemotionupdatestoqueuewithhandler

0.03 update every 30ms motionManager startDeviceMotionUpdatesToQueue NSOperationQueue mainQueue withHandler ^ CMDeviceMotion motion NSError error myAcceleration motion.userAcceleration.y while self.stopButtonPressed NSLog @ Y Axis acceleration..

Using quaternion instead of roll, pitch and yaw to track device motion

http://stackoverflow.com/questions/19239482/using-quaternion-instead-of-roll-pitch-and-yaw-to-track-device-motion

didFinishSavingWithError self.motionManager startDeviceMotionUpdatesToQueue NSOperationQueue mainQueue withHandler ^ CMDeviceMotion motion NSError error CMQuaternion quat self.motionManager.deviceMotion.attitude.quaternion double tempYaw radiansToDegrees..

Apple gyroscope sample code

http://stackoverflow.com/questions/3245733/apple-gyroscope-sample-code

device attitude and cause the device to continue sampling the gyro and updating its attitude property. void enableGyro CMDeviceMotion deviceMotion motionManager.deviceMotion CMAttitude attitude deviceMotion.attitude referenceAttitude attitude retain motionManager.. The code below retrieves and saves the current device motion. GLfloat rotMatrix 16 void getDeviceGLRotationMatrix CMDeviceMotion deviceMotion motionManager.deviceMotion CMAttitude attitude deviceMotion.attitude if referenceAttitude nil attitude multiplyByInverseOfAttitude..

Compensating compass lag with the gyroscope on iPhone 4

http://stackoverflow.com/questions/4212988/compensating-compass-lag-with-the-gyroscope-on-iphone-4

I want to compensate for the slowness of the compass by using data from the gyroscope. Using CMMotionManager and its CMDeviceMotion object motionManager.deviceMotion I get the CMAttitude object. Correct me if I'm wrong please but here is what I've deduced.. when I feel the compass has caught up. So my questions Am I on the right track with this Am I using the gyro data from CMDeviceMotion properly and the assumptions I listed above correct Why might yaw freak out when gravity.z is around 0 Thank you very much...

iphone - core motion range of yaw, pitch and roll

http://stackoverflow.com/questions/5004548/iphone-core-motion-range-of-yaw-pitch-and-roll

of gravity. To figure out if the screen is pointed down or up you can of course check gravity.z. If you're using CMDeviceMotion there is a property called gravity on it just grab gravity.z. It will be negative if the device's display is tilting upward.. upward away from gravity and positive if the display is facing down toward gravity Note that the algorithms used by CMDeviceMotion are pretty good at separating gravity from user acceleration but under certain kinds of motion there may be some lag before..

Actual frequency of device motion updates lower than expected, but scales up with setting

http://stackoverflow.com/questions/5034411/actual-frequency-of-device-motion-updates-lower-than-expected-but-scales-up-wit

polling using NSTimer or something and may pursue that yet. motionManager setDeviceMotionUpdateInterval updateInterval CMDeviceMotionHandler motionHandler ^ CMDeviceMotion motion NSError error self processMotion motion withError error motionManager startDeviceMotionUpdatesToQueue.. may pursue that yet. motionManager setDeviceMotionUpdateInterval updateInterval CMDeviceMotionHandler motionHandler ^ CMDeviceMotion motion NSError error self processMotion motion withError error motionManager startDeviceMotionUpdatesToQueue NSOperationQueue.. to confirm. 2. I'm sure that I'm tracking every call of processMotion there aren't any calls being made with nil CMDeviceMotion or other strangeness 3. I'm not doing any significant processing that would block things just waiting on motion events and..

iphone - core motion (relative rotation)

http://stackoverflow.com/questions/5053793/iphone-core-motion-relative-rotation

There is indeed. You can get what you're looking for by drilling down into the properties of CMMotionManager through CMDeviceMotion and finally to CMAttitude . The attitude of the device is defined as the orientation of a body relative to a given frame..

Store orientation to an array - and compare

http://stackoverflow.com/questions/6368618/store-orientation-to-an-array-and-compare

roll and yaw using self.motionManager startDeviceMotionUpdatesToQueue NSOperationQueue currentQueue withHandler ^ CMDeviceMotion motion NSError error CMAttitude attitude motion.attitude NSLog @ pitch f roll f yaw f attitude.pitch attitude.roll attitude.yaw..

Is there any way to remove the small bias along the gravity axis in the accelerometer data

http://stackoverflow.com/questions/9074947/is-there-any-way-to-remove-the-small-bias-along-the-gravity-axis-in-the-accelero

there any way to remove the small bias along the gravity axis in the accelerometer data Similar to this question CMDeviceMotion userAcceleration drift I'm using CMDeviceMotion.userAcceleration in iOS5 SDK to plot its x y z components over time. Like.. the gravity axis in the accelerometer data Similar to this question CMDeviceMotion userAcceleration drift I'm using CMDeviceMotion.userAcceleration in iOS5 SDK to plot its x y z components over time. Like the above post I see z acceleration component.. spreads over x y and z along the gravity axis if the device is in some arbitrary orientation. I know that the data in CMDeviceMotion.userAcceleration has already factored out the gravity using Gyro data but wonder if there is any effective way to remove..