On Wednesday 06 October 2010 17:33:33 Paul Schwarz wrote:
Hi Group,
I pose the following dilemma and look forward to enthusiastic discussions.
could you post plain old PDFs of the schematic. those flash-pdfs are a thorough pita.
As mentioned in a previous e-mail to you'll, we have developed an embedded PC with a touch screen. This device runs on a RMI, Alchemy processor (AU1250) and its touch screen is connected to this CPU via an ADS7843 chip and through the SPI bus. So far so good and pretty standard. The system originally ran on WinCE5.0 (Booooo!) and we are currently porting it to Linux.
Now the problem that we are facing is that after the first 3-4 touch events, no more touch events are recorded after that and the sensitivity of the clicks is very weak.
The input of the A-D converter is a high impedance source. In a noisy environment, the parasitic Cs charge up. This is usually the cause of gradual loss of sensitivity.
Lastly, when the screen is touched while a video is playing the video and audio pause for the duration of the touch.
this could definetly be the driver waiting for "release" event.