AR1000_16 Datasheet, PDF (6/61 Pages) Microchip Technology – AR1000 Series Resistive Touch Screen Controller

AR1000 SERIES RESISTIVE TOUCH SCREEN CONTROLLER
2.3 4-Wire Sensor
A 4-wire resistive touch sensor consists of a stable and
flex layer, electrically separated by spacer dots. The
layers are assembled perpendicular to each other. The
touch position is determined by first applying a voltage
gradient across the flex layer and using the stable layer
to measure the flex layer’s touch position voltage. The
second step is applying a voltage gradient across the
stable layer and using the flex layer to measure the
stable layer’s touch position voltage.
The measured voltage at any position across a driven
axis is predictable. A touch moving in the direction of
the driven axis will yield a linearly changing voltage. A
touch moving perpendicular to the driven axis will yield
a relatively unchanging voltage (See Figure 2-1).
FIGURE 2-1:
4-WIRE DECODING
DS40001393C-page 6
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