AR1011 datasheet(8/61 Pages) MICROCHIP

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AR1000 SERIES RESISTIVE TOUCH SCREEN CONTROLLER

DS40001393C-page 8

 2009-2016 Microchip Technology Inc.

2.5

5-Wire Sensor

A 5-wire resistive touch sensor consists of a flex and

stable layer, electrically separated by spacer dots. The

touch position is determined by first applying a voltage

gradient across the stable layer in the X-axis direction

and using the flex layer to measure the axis touch posi-

tion voltage. The second step is applying a voltage gra-

dient across the stable layer in the Y-axis direction and

using the flex layer to measure the axis touch position

voltage.

The voltage is not directly applied to the edges of the

active layer, as it is for 4-wire and 8-wire sensors. The

voltage is applied to the corners of a 5-wire sensor.

To measure the X-axis, the left edge of the layer is

driven with 0V (ground), using connections to the upper

left and lower left sensor corners. The right edge is

driven with +5 VDC, using connections to the upper

right and lower right sensor corners.

To measure the Y-axis, the top edge of the layer is

driven with 0V (ground), using connections to the upper

left and upper right sensor corners. The bottom edge is

driven with +5 VDC, using connections to the lower left

and lower right sensor corners.

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 2-3).

FIGURE 2-3:

5-Wire Decoding

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