smart board interactive whiteboard 600.When only one finger touches, the touch screen will work normally. For example, as shown in the figure below, the position X2, Y0 of the single touch can be accurately sensed by sequentially detecting all the X electrodes and Y electrodes. Measuring a single electrode rather than a crossover is a major drawback of a two-layer self-contained touchscreen - it is not possible to detect multi-touch clearly. The touch at two points of X2, Y0 and X1, Y3 actually produces four point coordinates. No matter what, when using a self-capacitive touch screen, the defect of the two-finger gesture operation cannot be completely solved. The secret is in the software - preferring to use ambiguous reporting methods to let the software recognize the direction of the report. In this case, it generates four point coordinates regardless of whether the two points are touched, as long as it can accurately recognize the two points that are far-right or opposite-moving gestures.