Motion triggered magnetic reading and compass heading calculations to reduce power consumption

• US 8,417,975 B2
• Filed: 11/24/2009
• Issued: 04/09/2013
• Est. Priority Date: 11/24/2009
• Status: Active Grant

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Bowdle, Aaron
• Primary Examiner(s): Bae, Ji H
• Application Number:
  US12/625,301
• Publication Number:
  US 20110121892A1
• Time in Patent Office: 1,232 Days
• Field of Search: None
• US Class Current: 713/320
• CPC Class Codes: G01C 17/28 Electromagnetic compasses with north seeking magnetic elements and having electric pick-offs G01C17/26

Abstract

A method for reducing power consumption of an electronic device is disclosed. In one embodiment, an indication that an electronic device is oriented in a first orientation is received. An indication of rotation of the electronic device around an axis is received. A command is then generated to cause an electronic compass module disposed within the electronic device to transition from an idle operating state to an active operating state and to generate a compass heading.

Claims

1. A method of reducing power consumption of an electronic device, said method comprising:

determining a first orientation of an electronic device;

coupling a rotation sensor with a power source in response to said determining;

receiving an indication of rotation of said electronic device around an axis; and

generating a command to cause an electronic compass module disposed within the electronic device to transition from an idle operating state to an active operating state and to generate a compass heading in response to said indication of rotation.

2. The method as recited in claim 1 further comprising:

receiving an indication that said electronic device is oriented in a substantially horizontal position; and

receiving an indication of rotation of said electronic device around an axis which is substantially orthogonal to said horizontal position.

3. The method as recited in claim 1 further comprising:

storing the compass heading; and

generating a command to cause said electronic compass module to return to said idle operating state.

4. The method as recited in claim 3 further comprising:

receiving a request for a compass heading;

determining that said electronic device has not rotated around said axis subsequent to said storing of said compass heading; and

accessing the stored compass heading in response to said request.

5. The method as recited in claim 3 further comprising:

determining that said electronic device has not been rotated around said axis for a pre-determined time period subsequent to the storing of the compass heading.

6. The method as recited in claim 1 further comprising:

generating a message for causing a position determining component communicatively coupled with said electronic compass module to transition from a suspended operating state to an active operating state.

7. The method as recited in claim 6 further comprising:

automatically generating a position fix of said electronic device in response to transitioning from said suspended operating state to said active operating state.

8. The method as recited in claim 7 further comprising:

storing said position fix of said electronic device.

9. A non-transitory computer readable storage medium having computer readable code stored thereon for causing an electronic device to implement a method for reducing power consumption, said method comprising:

determining a first orientation of an electronic device;

coupling a rotation sensor with a power source in response to said determining;

receiving an indication of rotation of said electronic device around an axis; and

generating a command to cause an electronic compass module disposed within the electronic device to transition from an idle operating state to an active operating state and to generate a compass heading in response to said indication of rotation.

10. The non-transitory computer readable storage medium as recited in claim 9, wherein said method further comprises:

receiving an indication that said electronic device is oriented in a substantially horizontal position; and

receiving an indication of rotation of said electronic device around an axis which is substantially orthogonal to said horizontal position.

11. The non-transitory computer readable storage medium as recited in claim 9, wherein said method further comprises:

storing the compass heading; and

generating a command to cause said electronic compass module to return to said idle operating state.

12. The non-transitory computer readable storage medium as recited in claim 11 wherein said method further comprises:

receiving a request for a compass heading;

determining that said electronic device has not rotated around said axis subsequent to said storing of the compass heading; and

accessing the stored compass heading in response to said request.

13. The non-transitory computer readable storage medium as recited in claim 11 wherein said method further comprises:

determining that said electronic device has not been rotated around said axis for a pre-determined time period subsequent to the storing of the compass heading.

14. The non-transitory computer readable storage medium as recited in claim 9 wherein said method further comprises:

generating a message for causing a position determining component communicatively coupled with said electronic compass module to transition from a suspended operating state to an active operating state.

15. The non-transitory computer readable storage medium as recited in claim 14 wherein said method further comprises:

automatically generating a position fix of said electronic device in response to transitioning from said suspended operating state to said active operating state.

16. The non-transitory computer readable storage medium as recited in claim 15 wherein said method further comprises:

storing said position fix of said electronic device.

17. A system for reducing the power consumption of an electronic device comprising:

a tilt sensor for determining that an electronic device is oriented in a first orientation;

a rotation sensor for determining rotation of said electronic device around an axis; and

a controller communicatively coupled with said tilt sensor and with said rotation sensor, said controller configured to couple said rotation sensor with a power source in response to said determining that said electronic device is oriented in a first orientation and to cause an electronic compass module disposed within the electronic device to transition from an idle operating state to an active operating state and to generate a compass heading in response to an indication of rotation of said electronic device around an axis.

18. The system as recited in claim 17, wherein said tilt sensor is configured to indicate that said electronic device is oriented in a substantially horizontal position and said rotation sensor is configured to indicate rotation of said electronic device around an axis which is substantially orthogonal to said horizontal position.

19. The system as recited in claim 17, further comprising:

a data storage component for storing the compass heading.

20. The system as recited in claim 19 wherein said controller is further configured to determine that said electronic device has not been rotated around said axis subsequent to receiving a request for a compass heading and to generate a reply to said request comprising the stored compass heading.

21. The system as recited in claim 17 wherein said controller is further configured to automatically generate a command to cause said electronic compass module to return to said idle operating state in response to determining that said electronic device has not been rotated around said axis for a pre-determined time period subsequent to the storing of the compass heading.

22. The system as recited in claim 17 further comprising:

a position determining component communicatively coupled with said controller and wherein said controller is further configured to generate a message for causing said position determining component to transition from a suspended operating state to an active operating state.

23. The system as recited in claim 22 wherein said position determining component is configured to automatically generate a position fix in response to said transitioning to an active operating state and wherein said controller is configure to initiate storing said position fix.