FIELD OF DISCLOSURE

The present disclosure relates in general to electronic devices with user interfaces, (e.g., mobile devices, game controllers, instrument panels, etc.), and more particularly, resonant phase sensing of resistive-inductive-capacitive sensors for use in a system for mechanical button replacement in a mobile device, and/or other suitable applications.

BACKGROUND

Many traditional mobile devices (e.g., mobile phones, personal digital assistants, video game controllers, etc.) include mechanical buttons to allow for interaction between a user of a mobile device and the mobile device itself. However, such mechanical buttons are susceptible to aging, wear, and tear that may reduce the useful life of a mobile device and/or may require significant repair if malfunction occurs. Also, the presence of mechanical buttons may render it difficult to manufacture mobile devices that are waterproof. Accordingly, mobile device manufacturers are increasingly looking to equip mobile devices with virtual buttons that act as a human-machine interface allowing for interaction between a user of a mobile device and the mobile device itself. Similarly, mobile device manufacturers are increasingly looking to equip mobile devices with other virtual interface areas (e.g., a virtual slider, interface areas of a body of the mobile device other than a touch screen, etc.). Ideally, for best user experience, such virtual interface areas should look and feel to a user as if a mechanical button or other mechanical interface were present instead of a virtual button or virtual interface area.

Presently, linear resonant actuators (LRAs) and other vibrational actuators (e.g., rotational actuators, vibrating motors, etc.) are increasingly being used in mobile devices to generate vibrational feedback in response to user interaction with human-machine interfaces of such devices. Typically, a sensor (traditionally a force or pressure sensor) detects user interaction with the device (e.g., a finger press on a virtual button of the device) and in response thereto, the linear resonant actuator may vibrate to provide feedback to the user. For example, a linear resonant actuator may vibrate in response to user interaction with the human-machine interface to mimic to the user the feel of a mechanical button click.

However, there is a need in the industry for sensors to detect user interaction with a human-machine interface, wherein such sensors provide acceptable levels of sensor sensitivity, power consumption, and size. One type of sensor that may be utilized to detect user interaction with a human-machine interface is a resistive-inductive-capacitive sensor.

In some instances, it may be desired to use multiple sensors. In such instances, it may be beneficial to avoid exciting it by measuring two sensors at the same time. Separating sensor usage in time may provide a number of benefits, including reducing parasitic coupling of noise between sensors and the ability to more evenly distribute power consumption over time, thus reducing a total simultaneous draw of electrical current required in a multiple-sensor system.

It may also be beneficial to avoid the need for an external clock source in a multiple-sensor system as well as minimize the number of electrically-conductive pins needed to operate the multiple-sensor system. Also, to minimize power consumption, an ability to control sensor scan rates using a low-power oscillator with relaxed accuracy and noise requirements may be beneficial.

In applications in which a single processing integrated circuit has sufficient electrical connections to support all sensors within a multiple-sensor system, a local scheduler may be used to time-division multiplex sensor activation and measurement. However, in many applications, the number of sensors may exceed the number of connections available within a single processing integrated circuit. In such an application, in order to realize benefits available to a multiple-sensor system from time-division multiplexing and low-power oscillators, approaches for synchronizing multiple processing integrated circuits for sensors may be desired.

SUMMARY

In accordance with the teachings of the present disclosure, the disadvantages and problems associated with sensing in multiple-sensor applications may be reduced or eliminated.

In accordance with embodiments of the present disclosure, a system may include a plurality of actively-driven inductive sensors and a plurality of control circuits, each control circuit of the plurality of control circuits configured to control operation of a respective set of the actively-driven inductive sensors, each control circuit of the plurality of control circuits communicatively coupled to the other control circuits via a connection configured to distribute synchronization information among the plurality of control circuits. Each of the plurality of control circuits may further be configured to configure a schedule for controlling time-division multiplexed operation of its respective set of actively-driven inductive sensors and control time-division multiplexed operation of its respective set of actively-driven inductive sensors based on the schedule and the synchronization information in order to minimize interference among the plurality of actively-driven inductive sensors.

In accordance with these and other embodiments of the present disclosure, a method may be provided for use in a system comprising a plurality of actively-driven inductive sensors and a plurality of control circuits, each control circuit of the plurality of control circuits configured to control operation of a respective set of the actively-driven inductive sensors, each control circuit of the plurality of control circuits communicatively coupled to the other control circuits via a connection configured to distribute synchronization information among the plurality of control circuits. The method may include configuring, by each control circuit of the plurality of control circuits, a schedule for controlling time-division multiplexed operation of its respective set of actively-driven inductive sensors and controlling, by each control circuit of the plurality of control circuits, time-division multiplexed operation of its respective set of actively-driven inductive sensors based on the schedule and the synchronization information in order to minimize interference among the plurality of actively-driven inductive sensors.

In accordance with these and other embodiments of the present disclosure, a host device may include an enclosure, a plurality of actively-driven inductive sensors integral to the enclosure, and a plurality of control circuits integral to the enclosure, each control circuit of the plurality of control circuits configured to control operation of a respective set of the actively-driven inductive sensors, each control circuit of the plurality of control circuits communicatively coupled to the other control circuits via a connection configured to distribute synchronization information among the plurality of control circuits, and each of the plurality of control circuits Each of the plurality of control circuits may further be configured to configure a schedule for controlling time-division multiplexed operation of its respective set of actively-driven inductive sensors and control time-division multiplexed operation of its respective set of actively-driven inductive sensors based on the schedule and the synchronization information in order to minimize interference among the plurality of actively-driven inductive sensors.

Technical advantages of the present disclosure may be readily apparent to one having ordinary skill in the art from the figures, description and claims included herein. The objects and advantages of the embodiments will be realized and achieved at least by the elements, features, and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are examples and explanatory and are not restrictive of the claims set forth in this disclosure.

