Also I see what you mean that i should only readthe touch screen if the data changes,
Well you have to read the touch screen first in order to determine if the data changes - but you shouldn't have to redisplay the data if it hasn't changed.
I know how to do that, but I cannot get accurate touch data at all, ...
What are the timing constraints concerning how often you can access the touch data? Are you observing those constraints?
Don