Abstract: An apparatus and method for controlling an oscillating device is presented. In particular, a controller for adjusting the frequency of a drive signal driving a haptic actuator is presented. The controller contains a calculator adapted to receive a first and a second measurement of the electrical parameter and to calculate a difference between the first measurement and the second measurement. The first measurement is obtained at a first sampling time and the second measurement is obtained at a second sampling time. The controller is adapted to provide a control signal to adjust a frequency of the drive signal based on the difference.

Abstract: An apparatus and method for stopping a linear resonant actuator is presented. A control system for use with an oscillating device has a response signal having a back electromotive force component and a driver adapted to provide a drive signal to the oscillating device. The control system has a sensor adapted to sense an electrical parameter of the response signal and a controller coupled to the sensor and to the driver. The controller has a calculator adapted to determine a sign of curvature of a portion of the response signal based on the electrical parameter, and the controller is adapted to provide a control signal to adjust the amplitude of the drive signal to slow down the oscillating device, and withdraw the drive signal upon identifying a change in the sign of curvature.

Abstract: An apparatus and method for adjusting an amplitude of a drive signal applied to a device are presented. The method of driving a device includes providing a drive signal to drive the device, monitoring a gradient value of the response signal; and changing an amplitude level of the drive signal based on the gradient value. The monitoring of the gradient value includes sensing an electrical parameter of the response signal and calculating the gradient value based on the electrical parameter.

Abstract: A haptic system with a haptic actuator and a voltage sensor coupled to the haptic actuator, to sense a voltage across the haptic actuator. The voltage across the haptic actuator has a back electromotive force component. There is a current regulator coupled to the haptic actuator and to the voltage sensor. The current regulator is adapted to provide a current signal to drive the haptic actuator and to adjust the current signal based on the back electromotive force component. For example, the voltage across the haptic actuator may be a direct voltage or a representation of the voltage such as a filtered value of the voltage.

Abstract: An apparatus and method for controlling an oscillating device is presented. In particular, a controller for adjusting the frequency of a drive signal driving a haptic actuator is presented. The controller contains a calculator adapted to receive a first and a second measurement of the electrical parameter and to calculate a difference between the first measurement and the second measurement. The first measurement is obtained at a first sampling time and the second measurement is obtained at a second sampling time. The controller is adapted to provide a control signal to adjust a frequency of the drive signal based on the difference.

Abstract: An apparatus and method for stopping a linear resonant actuator is presented. A control system for use with an oscillating device has a response signal having a back electromotive force component and a driver adapted to provide a drive signal to the oscillating device. The control system has a sensor adapted to sense an electrical parameter of the response signal and a controller coupled to the sensor and to the driver. The controller has a calculator adapted to determine a sign of curvature of a portion of the response signal based on the electrical parameter, and the controller is adapted to provide a control signal to adjust the amplitude of the drive signal to slow down the oscillating device, and withdraw the drive signal upon identifying a change in the sign of curvature.

Abstract: An apparatus and method for adjusting an amplitude of a drive signal applied to a device are presented. The method of driving a device includes providing a drive signal to drive the device, monitoring a gradient value of the response signal; and changing an amplitude level of the drive signal based on the gradient value. The monitoring of the gradient value includes sensing an electrical parameter of the response signal and calculating the gradient value based on the electrical parameter.

Abstract: A haptic system with a haptic actuator and a voltage sensor coupled to the haptic actuator, to sense a voltage across the haptic actuator. The voltage across the haptic actuator has a back electromotive force component. There is a current regulator coupled to the haptic actuator and to the voltage sensor. The current regulator is adapted to provide a current signal to drive the haptic actuator and to adjust the current signal based on the back electromotive force component. For example, the voltage across the haptic actuator may be a direct voltage or a representation of the voltage such as a filtered value of the voltage.

Abstract: Systems and methods to achieve a digital audio interface having automatic rate detection and tracking of digital audio streams have been achieved. The system comprises a digital controller working in conjunction with an analog phase-locked loop (PLL). It removes the need to know or communicate in advance the rate at which the interface will be operating, so allowing asynchronous switching between different audio streams. The digital controller acts as a phase-lock loop by modifying the feedback divide ratio of the PLL in order to minimize the phase error between the device clock and an arbitrary audio interface clock.

Abstract: Systems and methods to achieve a digital audio interface having automatic rate detection and tracking of digital audio streams have been achieved. The system comprises a digital controller working in conjunction with an analog phase-locked loop (PLL). It removes the need to know or communicate in advance the rate at which the interface will be operating, so allowing asynchronous switching between different audio streams. The digital controller acts as a phase-lock loop by modifying the feedback divide ratio of the PLL in order to minimize the phase error between the device clock and an arbitrary audio interface clock.