2014/10/15 下午 10:11:14

iphone Programming Glossary: magnetic

iPhone 3.0 Compass: how to get a heading?

http://stackoverflow.com/questions/1043740/iphone-3-0-compass-how-to-get-a-heading

don't know much about it yet so I apologise for what is probably a really amateurish question. I'm trying to get the magnetic heading from CLHeading and CLLocationDirection. However I'm getting compile errors for this line of code locationLabel.text.. and CLLocationDirection. However I'm getting compile errors for this line of code locationLabel.text location course magneticHeading stringValue The errors are warning invalid receiver type 'CLLocationDirection' error cannot convert to a pointer..

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

am I getting 0 degrees from magneticField property the whole time I'm trying to get the device's declination from the magnetic North in degrees by relying solely.. am I getting 0 degrees from magneticField property the whole time I'm trying to get the device's declination from the magnetic North in degrees by relying solely on the device's magnetometer. This is the code I've written but I just get 0 degrees.... deviceMotion deviceMotion CMDeviceMotion alloc init while self.stopButtonPressed double x motionManager.deviceMotion.magneticField.field.x double y motionManager.deviceMotion.magneticField.field.y double degrees asin y sqrt pow x 2.0 pow y 2.0 180.0..

Compensating compass lag with the gyroscope on iPhone 4

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

upwards yaw ranges from PI to 0 and PI to 0 respectively and from the compass data I'm using locationManager.heading.magneticHeading I see that the compass gives values from 0 to 360 with the value increasing when swinging clockwise All right so.. around 0 the yaw value freaks out at this gravity.z value . It seems to me that I could synchronize the horizontal and magneticHeading values using a calculated horizontal value that maps to magneticHeading and synchronize the horizontal value to magneticHeading.. me that I could synchronize the horizontal and magneticHeading values using a calculated horizontal value that maps to magneticHeading and synchronize the horizontal value to magneticHeading when I feel the compass has caught up. So my questions Am..

Multi Select Table View Cell and no Selection Style

http://stackoverflow.com/questions/4890900/multi-select-table-view-cell-and-no-selection-style

Point to location using compass

http://stackoverflow.com/questions/5092845/point-to-location-using-compass

location. I have calculated the degress from the user's location to the location of the annotation and I have the magnetic heading and the true heading of the iPhone. Also I know how to rotate an image. But I can't figure out what the next step.. result 270 else result atan dy dx 180 M_PI if dx 0 result result 180 if result 0 result result 360 The true and the magnetic heading is retrieved like this void locationManager CLLocationManager manager didUpdateHeading CLHeading newHeading arrow.transform.. manager didUpdateHeading CLHeading newHeading arrow.transform CGAffineTransformMakeRotation newHeading.magneticHeading NSLog @ magnetic heading f newHeading.magneticHeading NSLog @ true heading f newHeading.trueHeading Can anyone tell..

iPhone headphone jack - read in data?

http://stackoverflow.com/questions/7192473/iphone-headphone-jack-read-in-data

as when you started turning the wheel and how fast the wheel is turning. I believe the device is sending some sort of magnetic pulse or something through the 3.5 mm audio jack . Instead of connecting the device to its original monitor I want to connect..

IPhone vs Android [closed]

http://stackoverflow.com/questions/932522/iphone-vs-android

offering pretty much the same capabilities as the iPhone including capacitive touch screen similar display size GPS magnetic compass etc but for less than half the price and no carrier lock in . Of the major competing mobile platforms Symbian Maemo..