Abstract: An integrated circuit includes a processor configured to receive position data corresponding to positions of objects relative to a touch-sensitive interface. The processor is configured to determine a first index point for the position data and a second index point of previous position data corresponding to previous positions of the objects relative to the touch-sensitive interface. The processor aligns the first and second index points and assigns an index to link the positions of the objects to the previous positions based on distances between the objects in the position data relative to the previous position data.

Abstract: A circuit includes an interface circuit configured to couple to a capacitive array of a touch screen and a driver circuit coupled to the interface circuit and configured to selectively provide signals to the interface circuit. The circuit further includes at least one sensor coupled to the interface circuit for detecting when a change in a capacitance of one a plurality of capacitances associated with the capacitive array exceeds a baseline threshold. The circuit further includes a control circuit coupled to the driver circuit and to the at least one sensor and configured to determine a fluctuation of the capacitance over a period of time. The control circuit determines that the change is caused by unwanted matter when the fluctuation is less than or equal to a noise threshold and by a user input when the fluctuation exceeds the noise threshold.