iPhone 3GS: Re-calibrate Compass
Symptoms
In Compass or Maps, iPhone 3GS may display the message "Re-calibrate Compass. Wave in a figure 8 motion."
iPhone 3GS periodically displays the message to re-calibrate Compass.
Products Affected
iPhone 3GS
Resolution
iPhone 3GS has a built-in digital compass that works just like a magnetic needle compass. The accuracy of digital compass headings can be affected by magnetic or other environmental interference, including interference caused by the close proximity of the magnets contained in the iPhone earbuds. The compass may need to be calibrated from time to time. iPhone 3GS alerts you whenever calibration is needed. To calibrate, hold iPhone 3GS in your hand and move the device in a figure 8 motion until the calibration screen disappears. The digital compass should only be used for basic navigation assistance and should not be solely relied on to determine precise locations, proximity, distance, or direction.
Additional Information
Some areas have more magnetic interference than others. For example, your car's dashboard may have a high level of magnetic interference. If you wish to mount iPhone 3GS on a car's dashboard and use Compass or Maps, do not wave the device in a figure 8 to calibrate. Instead, mount iPhone 3GS, open Compass or Maps, and disregard the message to calibrate. iPhone 3GS will eventually re-calibrate after several turns. Note that it may need to periodically recalibrate while you are driving, depending on the level of magnetic interference present where you have it mounted.