Databases
StackOverflow2013
Postsdbo
POHaving a problem with Core Motion gyro rotation
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHaving a problem with Core Motion gyro rotation
    primarykey
    data
    text
    <p>I'm working on an app that needs to detect a rotation gesture from the iPhone. I have written code that polls CMMotionManager for rotation data, but for some reason these values are constantly changing even though the phone is stationary on the table. I'm not sure what I am doing wrong here. I have consulted the Apple docs and it seems like I am doing what they suggest, and the thing does run without crashing, but the numbers that come out make no sense. Here is what I am doing:</p> <pre><code> -(void)startDetectingMotion { if (!motionQueue){ motionQueue = [[NSOperationQueue mainQueue] retain]; } if (motionManager.isDeviceMotionAvailable) { CMDeviceMotionHandler motionHandler = ^ (CMDeviceMotion *motion, NSError *error) { [self processMotion:motion withError:error]; }; [motionManager startDeviceMotionUpdatesToQueue:motionQueue withHandler:motionHandler]; } else { NSLog(@"motion not available"); } } </code></pre> <p>.....</p> <pre><code>-(void)processMotion:(CMDeviceMotion *)motion withError:(NSError *)error { CMRotationRate rotation = motion.rotationRate; if(rotation.y &gt; 2 || rotation.y &lt; -2) { NSLog(@"CM Motion X rotation:%f, Y rotation:%f, Z Rotation:%f", rotation.x, rotation.y, rotation.y); .... [self stopDetectingMotion]; } } </code></pre> <p>The point of trapping for y > 2 or &lt; 2 is to look for rapid rotation of the iphone on a horizontal plane, which is what I am looking for.</p> <p>The output looks like this:</p> <p>2010-08-15 16:15:43.475 PokerFoldTest[539:307] CM Motion X rotation:11.415660, Y rotation:7.865920, Z Rotation:7.865920</p> <p>2010-08-15 16:04:33.843 PokerFoldTest[539:307] CM Motion X rotation:8.925084, Y rotation:8.414384, Z Rotation:8.414384</p> <p>2010-08-15 16:11:14.314 PokerFoldTest[539:307] CM Motion X rotation:10.245130, Y rotation:-8.243847, Z Rotation:-8.243847</p> <p>2010-08-15 16:11:16.136 PokerFoldTest[539:307] CM Motion X rotation:10.212860, Y rotation:-4.303616, Z Rotation:-4.303616</p> <p>2010-08-15 16:11:18.242 PokerFoldTest[539:307] CM Motion X rotation:9.988654, Y rotation:-7.074587, Z Rotation:-7.074587</p> <p>2010-08-15 16:11:19.678 PokerFoldTest[539:307] CM Motion X rotation:16.092894, Y rotation:-10.562743, Z Rotation:-10.562743</p> <p>2010-08-15 16:15:41.662 PokerFoldTest[539:307] CM Motion X rotation:12.854285, Y rotation:7.247667, Z Rotation:7.247667</p> <p>As these numbers are supposed to be radians/sec rotation, they are suggesting that when the phone is stationary on the table it is spinning wildly. What the hell? Any chance my phone has a bad gyro?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USfogelbaby
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload