System and Method for Calibrating a Magnetometer According to Device States

1 . A method of calibrating a magnetometer on a mobile device, the method comprising:

detecting a change in a physical configuration of the mobile device;

applying at least one stored calibration parameter as a respective active calibration parameter when one or more stored calibration parameters corresponding to the detected physical configuration change are accessible by the mobile device; and

performing a calibration to obtain at least one additional calibration parameter when the at least one additional calibration parameter is needed and applying the at least one additional calibration parameter as a respective active calibration parameter.

2 . The method according to claim 1 , further comprising:

performing a calibration to obtain at least one new calibration parameter when no stored calibration parameters exist for the detected state; and

storing the obtained new calibration parameters.

3 . The method according to claim 2 , further comprising:

determining that the detected state is a new state;

determining a detectable characteristic for the new state; and

storing the detectable characteristic to enable the new state to be subsequently identified.

4 . The method according to claim 1 , further comprising storing the obtained parameter for each of the at least one additional calibration parameter.

5 . The method according to claim 1 , wherein the at least one additional calibration parameter is obtained by performing a partial calibration associated with only the at least one additional calibration parameter.

6 . The method according to claim 1 , wherein after detecting the change in state, determining if a rough offset of a constant bias is needed and performing a rough offset calculation to bring the magnetometer back into a useable range when the rough offset is needed.

7 . A computer readable storage medium comprising computer executable instructions for calibrating a magnetometer on a mobile device, the computer executable instructions comprising instructions for:

detecting a change in a physical configuration of the mobile device;

applying at least one stored calibration parameter as a respective active calibration parameter when one or more stored calibration parameters corresponding to the detected physical configuration change are accessible by the mobile device; and

performing a calibration to obtain at least one additional calibration parameter when the at least one additional calibration parameter is needed and applying the at least one additional calibration parameter as a respective active calibration parameter.

8 . The computer readable medium according to claim 7 , further comprising instructions for:

performing a calibration to obtain at least one new calibration parameter when no stored calibration parameters exist for the detected state; and

storing the obtained new calibration parameters.

9 . The computer readable medium according to claim 8 , further comprising instructions for;

determining that the detected state is a new state;

determining a detectable characteristic for the new state; and

storing the detectable characteristic to enable the new state to be subsequently identified.

10 . The computer readable medium according to claim 7 , further comprising instructions for storing the obtained parameter for each of the at least one additional calibration parameter.

11 . The computer readable medium according to claim 7 , wherein the at least one additional calibration parameter is obtained by performing a partial calibration associated with only the at least one additional calibration parameter.

12 . The computer readable medium according to claim 7 , wherein after detecting the change in state, determining if a rough offset for a constant bias is needed and performing a rough offset calculation to bring the magnetometer back into a useable range when the rough offset is needed.

13 . A mobile device comprising a processor coupled to a memory, and a magnetometer, the memory comprising computer executable instructions for calibrating the magnetometer, the computer executable instructions comprising instructions for:

detecting a change in a physical configuration of the mobile device;

applying at least one stored calibration parameter as a respective active calibration parameter when one or more stored calibration parameters corresponding to the detected physical configuration change are accessible by the mobile device; and

performing a calibration to obtain at least one additional calibration parameter when the at least one additional calibration parameter is needed and applying the at least one additional calibration parameter as a respective active calibration parameter.

14 . The mobile device according to claim 13 , further comprising instructions for:

performing a calibration to obtain at least one new calibration parameter when no stored calibration parameters exist for the detected state; and

storing the obtained new calibration parameters.

15 . The mobile device according to claim 14 , further comprising instructions for:

determining that the detected state is a new state;

determining a detectable characteristic for the new state; and

storing the detectable characteristic to enable the new state to be subsequently identified.

16 . The mobile device according to claim 13 , further comprising instructions for storing the obtained parameter for each of the at least one additional calibration parameter.

17 . The mobile device according to claim 13 , wherein the at least one additional calibration parameter is obtained by performing a partial calibration associated with only the at least one additional calibration parameter.

18 . The mobile device according to claim 13 , wherein after detecting the change in state, determining if a rough offset for a constant bias is needed and performing a rough offset calculation to bring the magnetometer back into a useable range when the rough offset is needed.

19 . A method of calibrating a magnetometer on a mobile device, the method comprising:

detecting a change in a physical configuration of the mobile device;

determining that no calibration is required for the detected state; and

foregoing calibration of the magnetometer while in the detected state.