I am using an analog touchscreen on four ports of an AVR.
To get the coordinates I put a voltage on the TOP and BOTTOM pins of the touch screen and measure the voltage on one LEFT pin (and the other way round to get x and y).
It is working fine, as long as I actualy touch it. But when the touchscreen is not touched, it seems to float and I get a random values. That makes it impossible to use the coordinates, because I can not determin if it is a floating value or a touche value.
This must be a common issue. Is there any way to solve this?