I'm afraid i'm still losing sleep over this one:
When one presses on a resistive touchpanel, there is a minute ramp up to the 'exact' or real XY location value; this is mainly due to the mechanics of this type of sensor implementation, but also caused in some part by a function i have implemented to simply detect touch: when the device is 'dormant', the sensors are forced back to ground, giving me a zero. Nice. And in Processing I've got a little averaging array. But the ramping-up noise is still there and giving me nightmares etc, so I've implemented three different algorithms in Max to try to address this issue; 1. a simple gate for discrete touches; 2. a lowpass onepole filter + zl stream/zl median; 3. downsampling.
I hope to be able to access both discrete and continuous touch data accurately, and, having pounded this forum and others mercilessly, still no success........please have a glance at the commented patch below and suggest anything (except [lbyl], it does lowfreq noise very well but not applicable in this instance): capacitors, welding rods, a hammer whatever!
That's two queries then i suppose; how to deal with ramping to, and vacillation around the 'real' touch value; and, how to access both discrete and continuous touch data.
Brendan (the 'touchpanel-noise guy', that's me)