Touchscreen input jitter

[Dr. H. Nikolaus Schaller]

Am 03.08.2007 um 16:55 schrieb Nuutti Kotivuori:

> I have noticed that every time the stylus (or anything else) presses
> on the screen, there is a constant jitter or vibration on the pointer
> position. It seems to be totally impossible to touch the screen and

I see the same - most notably when in the Terminal application.

I remember that there have been similar issues on the Sharp Zaurus.
For example, there was an X11 server using ztsd (Zaurus Touch Screen
Driver) which did a lot of intelligent buffering and smooting  
calculations
but was never as good as the X/Qt touch screen driver.

  From my understanding there is some crosstalk of the LCD scanning
signals to the input of the ADC. So, syncing the ADC readout with the
vertical retrace could help to stabilize.

Nikolaus