SYSTEM AND METHOD FOR ALIGNING SENSOR DATA TO SCREEN REFRESH RATE

• US 20160240168A1
• Filed: 02/16/2015
• Published: 08/18/2016
• Est. Priority Date: 02/16/2015
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: KEAL, WILLIAM KERRY, LIM, JAMES B.
• Granted Patent: US 10,706,818 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: G01C 21/16 by integrating acceleration or speed, i.e. inertial navigation
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: G06F 1/1694 the I/O peripheral being a single or a set of motion sensors for pointer control or gesture input obtained by sensing movements of the portable computer
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 2200/1637 Sensing arrangement for detection of housing movement or orientation, e.g. for controlling scrolling or cursor movement on the display of an handheld computer
• CPC Class Codes: G06F 3/002 Specific input/output arrangements not covered by G06F3/01 - G06F3/16 other optical apparatus G02B27/00
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/08 Arrangements within a display terminal for setting, manually or automatically, display parameters of the display terminal
• CPC Class Codes: G09G 5/12 Synchronisation between the display unit and other units, e.g. other display units, video-disc players

Abstract

A method and system to a system to provide a sensor data to a host device is disclosed. The system includes a first clock generator that generates a first clock. The system also includes a second clock generator that generates a second clock. The sensor data is sampled based on the first clock. The sensor data is presented to the host device, based on the second clock.

Claims

1. A method for providing a sensor data to a host device, comprising:

sampling the sensor data based on a first clock; and

presenting the sensor data to the device based on a second clock.

2. The method of claim 1, further including generating the first clock in a MEMS device with the sensor and generating the second clock in the host device.

3. The method of claim 1, wherein the frequency of the first clock is substantially a multiple of the frequency of the second clock.

4. The method of claim 1, further including

sampling the sensor data based on the first clock ahead of presenting the sensor data to the host device based on the second clock;

and

modifying the sampled sensor data to project likely sensor data at the time of presenting the sensor data to the host device based on the second clock.

5. The method of claim 1, wherein the second clock corresponds to a display screen refresh rate of the host device.

6. The method of claim 4, wherein the first clock is substantially a multiple of the second clock and selecting a clock cycle of the first clock by a delay that is at least ahead of a corresponding clock cycle of the second clock to sample the sensor data.

7. The method of claim 6, wherein the delay is at least sufficient to permit sampling and presenting of sensor data to the host device.

8. The method of claim 1, wherein the first clock is at least twice the frequency of the second clock.

9. The method of claim 1, wherein the sensor is at least one of an accelerometer, gyroscope and a magnetometer.

10. The method of claim 2, wherein the MEMS device generates an interrupt to the host device, to present the sensor data to the host device.

11. The method of claim 10, wherein the host device includes an application processor and the interrupt awakes the application processor, upon issuance of the interrupt.

12. The method of claim 11, wherein the application processor is in a sleep mode, prior to receipt of the interrupt from the MEMS device.

13. The method of claim 1, wherein the sensor data based on the first clock is

converted to a first signal indicative of the orientation of the device with reference to a stationary frame, wherein the first signal is a quaternion.

14. The method of claim 13, wherein the first signal is modified to generate a second signal indicative of the orientation of the device based on a delay between the first clock and the second clock.

15. The method of claim 14, further including refreshing a display screen of the host device, based on the second clock, wherein the display screen is refreshed based on the orientation indicated by the second signal.

16. A system to provide a sensor data to a host device, comprising:

a first clock generator to generate a first clock;

a second clock generator to generate a second clock;

sensor data sampled based on the first clock; and

sensor data presented to the device based on the second clock.

17. The system of claim 16, wherein

a MEMS device includes the sensor and the first clock generator;

and

the second clock generator is in the host device.

18. The system of claim 16, wherein the frequency of the first clock is substantially a multiple of the frequency of the second clock.

19. The system of claim 16, wherein

the sensor data is sampled based on the first clock before the sensor data is presented to the host device based on the second clock;

and

the sampled sensor data is modified to project likely sensor data at the time the sensor data is presented to the host device based on the second clock.

20. The system of claim 16, wherein the second clock corresponds to a display screen refresh rate of the host device.

21. The system of claim 18, wherein the first clock is substantially a multiple of the second clock and a clock cycle of the first clock is selected by a delay that is least ahead of a corresponding clock cycle of the second clock to sample the sensor data.

22. The system of claim 21, wherein the delay is at least sufficient to permit sampling and presenting of sensor data to the host device.

23. The system of claim 16, wherein the first clock is at least about twice the frequency of the second clock.

24. The system of claim 16, wherein the sensor is at least one of accelerometer, gyroscope and a magnetometer.

25. The system of claim 17, wherein the MEMS device generates an interrupt to the host device, to present the sensor data to the host device.

26. The system of claim 25, wherein the host device includes an application processor and the interrupt awakes the application processor, upon issuance of the interrupt.

27. The system of claim 26, wherein the application processor is in a sleep mode, prior to receipt of the interrupt from the MEMS device.

28. The system of claim 16, wherein the sensor data based on the first clock is

converted to a first signal indicative of the orientation of the device with reference to a stationary frame, wherein the first signal is a quaternion.

29. The system of claim 28, wherein the first signal is modified to generate a second signal indicative of the orientation of the device based on a delay between the first clock and the second clock.

30. The system of claim 29, wherein a display screen of the host device is refreshed based on the second clock and the display device is refreshed based on the orientation indicated by the second signal.