66.6.15.5 5-wire Resistive Touchscreen Principles

To make a 5-wire touchscreen, a resistive layer with a contact point at each corner and a conductive layer are used.

The 5-wire touchscreen differs from the 4-wire type mainly in that the voltage gradient is applied only to one layer, the resistive layer, while the other layer is the sense layer for both measurements.

The measurement of the X position is obtained by biasing the upper left corner and lower left corner to VDDANA and the upper right corner and lower right to ground.

To measure along the Y axis, bias the upper left corner and upper right corner to VDDANA and bias the lower left corner and lower right corner to ground.

Figure 66-17. 5-Wire Principle