Touchpad pen-input and mouse controller

摘要

Systems and methods for the detection of motions of a pointed object upon a writing surface such as a touchpad is disclosed. The motions will be detected and converted in a multiplexing analog-to-digital converter to digital codes representing the location of the pointed object and the pressure of the pointed object upon the touchpad. The location and the pressure will be translated into a pen detect signal indicating the presence of the pointed object upon the touchpad. The pen detect signal will be translated into a stroke signal to interpret a single tap, a double tap, and a tap and drag of the pointed object on the touchpad. The digital codes will be averaged to minimize noise and formed into an absolute coordinates digital code. The absolute coordinate digital code, the pressure digital code, and the pen detect signal will be converted to a touchpad-computer interface protocol. Further, multiple sets absolute coordinates will translated into a relative motion code. The absolute coordinates will be interpreted by an autocursor controller to determine if the pointed object has transited between a workzone and an edgezone of the touchpad to generate an autocursor code. The relative motion code, the stroke signal, and the autocursor code will converted to an industry standard computer input mouse protocol. An autopower control circuit and a battery gauge circuit will determine and control the battery condition.