11.1 Overview

The scroller module processes the group of touch sensors constructed either as a linear slider or circular wheel, as shown in the figure below. The slider/wheel sensors, also known as one-dimensional surface sensors, track the touch movement scrolled over them and report the state and the position to the user application. The size of the slider/wheel is the underlying number of the touch key sensors that form the linear/circular surface.

The slider/wheel can be formed by using both self-capacitance and mutual capacitance sensors. The figure above shows the 4-channel slider and 3-channel wheel sensors based on self-capacitance technology. To get good linearity on the reported touch positions when the touch is scrolled over the sensor surface, the touch keys should be interleaved, as shown in the figure above.