The iPhone 3G S documentation indicates that "The icon at the bottom of the Compass screen lets you find your current location in Maps. Maps also takes advantage of the built-in compass to show which way you’re facing."
Initially I couldn't make it work as unfortunately there is no more information presented on how to make that work!
Here's the secret.
After days of frustrated trying I discovered that there are THREE icon states in the bottom left corner of the Maps Ap. These icons rotate in appearance with each successive tap on it. The default (startup icon) is "not using current location" (no highlight behind the location circle icon); followed by "Use Current Location" (the location circle icon background is highlighted); and a THIRD icon in the rotation sequence.
This icon (shown in the red circle on the Map image above right) is a circle with a "beam" image at the top. When this (third) icon is selected, the Map auto rotates to a position that "Up" is the direction the top of the iPhone is pointing.
Now as you turn around, the Map will auto-rotate to follow your orientation.
Thank You
Thank you for sharing this useful information.
map app
is this app available to users of non 3gs phones. if so how do i get it
Compass "App"
Good question.
Unfortunately this "Ap" is a part of the riPhone release 3.0 operating system, and is only enabled when it senses that the OS is installed on a 3G S phone. The compass Ap requires a hardware chip called a "magnetometer" to be on the mother board. This is the same component that gives cars their digital electronic compass. Only the 3G S phones have this compass chip installed on their internal circuit boards.
That said, you can simulate the compass functionality with a number of GPS Aps for the iPhone. These work on any iPhone, but NOTE that while they can give compass readings, they can only do so when you are MOVING. They do not work when you are still, as they compute the compass headed by computing it based on the motion vector determined from GPS readings for multiple points along a path.