How to calculate speed of our car using iphone

Question

For my application I want to calculate my car/bike speed using iphone. How can i do that? Ideally, it should run continuously in the background.

Answer 1

CLLocation includes a speed property that will give you the current speed of the device. (Note the comment about the accuracy at that link.)

To get the user's current location, follow the steps in the Location Awareness Programming Guide, under "Getting the User's Current Location".

Finally, to enable location updates in the background, see Receiving Location Events in the Background in the iOS Application Programming Guide.