thank you for the reply, i was beating myself up trying to figure out what i was doing wrong before i realized it might just be the cheap screen.
i wonder if larger screens in the 30$ are accurate. does anyone have any recommendations?
If you can work out the change in values then you could use the x value to correct (map) and add to the y values accordingly (if the change is linear). Same with correcting the y.
5 wire touch screens are in general more accurate but I am not sure how to use them with an arduino. Maybe someone else knows. I have not got any experience with more expensive screens though. If you put in a calibrartion routine and mao values from that then it would sort out the errors.
Regarding the 0 value you want to send over MIDI, if you look at: http://mnicolato.altervista.org/arduino/ardtouch.htm which I presume is what you used the code from anyway (or somewhere that copied it) then there is boolean touched(); that reads if the screen is touched and sets it to true. You could then use an if command for if it's false to then send your 0 MIDI value...