Two-touch gesture detection on a four-wire resistive touchscreen

摘要

Embodiments of a touchscreen control device and associated method of operation enable two-touch gesture detection on a four-wires resistive touchscreen. Illustrative devices and methods enable detection when a resistive touchscreen is touched in two separate points. Embodiments of an electronic circuit can comprise a controller configured for coupling to a four-wires resistive touchscreen and at least two resistors. The controller can be further configured to detect multiple touches on the four-wires resistive touchscreen and measure zoom gestures comprising measuring distances between two-touches and obtaining angle of rotation and total distance between the two-touches.

主权项

1. An electronic circuit comprising:
a controller configured for coupling to a four-wires resistive touchscreen; and at least two resistive elements coupled to resistive circuits of the four-wires resistive touchscreen, wherein the controller is configured to
detect multiple touches on the four-wires resistive touchscreen,measure zoom gestures comprising measuring distances between two-touches and calculating an angle of rotation and a total distance between the two-touches, andperform two-touch detection by virtue of being further configured to
calibrate to calculate a plurality of touch calibration values comprising sampling for a single touch;repeat sampling of the single touch multiple times;capture two-touch delta for maximum distance in a first axis;capture two-touch delta for maximum distance in a second axis; andcalculate distance resolution and touch calibration values corresponding to the first axis and the second axis by calculating distances according to at least equations (1) (X axis physical distance)2 times Kx is equal to an X two-touch delta, and (2) (Y axis physical distance)2 times Ky is equal to a Y two-touch delta, wherein Kx and Ky are touch calibration values.