5-wire resistive touch panel


That pdf has the info for the screens I have... the pin out says

1 UR 2 LR 3 Sense 4 UL 5 LL

according to the sheet. One can only assume that this means upper right, lower right, sensor, upper left, and lower left respectively.

My question is this... I want to hook this up to my arduino to get some data from it, but I'm not even sure where to begin. I *assumed before I got the screen that it would want some sort of power supply and ground pins on the screen. I really don't know where to start. All I really want to do to begin with is to get some x,y coordinates output into the console on the arduino IDE. I could probably figure things out from there.

Any help would be greatly appreciated.

I think touchpads like this are scanned by applying a voltage and treating the circuit like a voltage divider. In other words, the usual Arduino analog input connected to a potentiometer. The only catch is that you must make two measurements of voltage, one for X and the other for Y. To do that, you must apply power to the left-right terminals (while leaving up-down open circuit) and then measure the "sense" voltage. Repeat with up-down powered (left-right open) and read voltage again. The Arduino digital outputs can probably be used, but you'll need to find a way to make them go open-circuit. Can "pinMode()" be used to make an output pin go tri-state?

Have a look at this app note:- www.atmel.com/dyn/resources/prod_documents/doc8091.pdf

Can "pinMode()" be used to make an output pin go tri-state?

If you call pinMode(n, INPUT), then the pin is in the hi-impedance state, almost disconnected from the circuit. You should also digitalWrite(n, LOW) so that the internal 20Kohm pullups are not employed.