Pointing electronic device with fast start-up recovery and corresponding method

An electronic system comprising:

• a pointing electronic device, comprising:
• an accelerometer sensor, configured to generate an acceleration signal indicative of accelerations acting on the pointing electronic device;
• a gyroscope sensor, configured to generate a gyroscopic signal indicative of angular rates of rotation of the pointing electronic device;
• a sensor fusion processing stage, coupled to the accelerometer sensor and gyroscope sensor, configured to generate an orientation estimation quantity indicative of an orientation of the pointing electronic device about a longitudinal axis based on a sensor fusion algorithm comprising joint processing of the acceleration signal and gyroscopic signal;
• a pointing determination stage, configured to:
• implement an orientation-compensation of the gyroscopic signal as a function of the orientation estimation quantity to determine an orientation-compensated gyroscopic signal;
• and
• generate screen-frame displacement data corresponding to 3D-space movements of the pointing electronic device based on the orientation-compensated gyroscopic signal;
• a first processing block, configured to:
• store past values of the acceleration signal, during a time interval preceding start-up;
• and
• upon start-up, retrieve and process the stored past values of the acceleration signal to generate processed acceleration data, for use by the sensor fusion processing stage to initialize the sensor fusion algorithm and generate a starting value of a roll estimation quantity after pointing operation by the pointing electronic device is enabled;
• and
• a first communication interface unit configured to transmit the screen-frame displacement data;
• and
• a host apparatus, coupled to the pointing electronic device, and comprising:
• a second communication interface, configured to:
• communicate with the pointing electronic device;
• and
• receive the screen-frame displacement data;
• a display defining a screen frame;
• and
• a main controller, configured to control movement of a displayed element on the screen frame of the display according to the screen-frame displacement data received by the second communication interface.

A method for generating screen-frame displacement data based on 3D-space movements of a pointing electronic device, the method comprising:

• generating an orientation estimation quantity indicative of an orientation of the pointing electronic device about a longitudinal axis based on a sensor fusion algorithm comprising joint processing of an acceleration signal, indicative of accelerations acting on the pointing electronic device, and of a gyroscopic signal, indicative of angular rates of rotation of the pointing electronic device;
• implementing an orientation-compensation of the gyroscopic signal as a function of the orientation estimation quantity to determine an orientation-compensated gyroscopic signal;
• generating the screen-frame displacement data corresponding to the 3D-space movements of the pointing electronic device based on the orientation-compensated gyroscopic signal;
• storing past values of the acceleration signal, during a time interval preceding start-up;
• and
• upon start-up after pointing operation by the pointing electronic device is enabled, retrieving and processing the stored past values of the acceleration signal to generate processed acceleration data, for initializing the sensor fusion algorithm and generating a starting value of a roll estimation quantity.