Re: [Gumstix-users] LCD touch screen unusable on Overo/Chestnut

[dcraw101 <dcr...@ya...>]

JamesAng wrote:
> 
> 
> BrentP wrote:
>> 
>> James:
>> 
>> I didn't actually get as far as modifying the driver just yet.  I had to
>> put my Gumstix project on the back burner soon after posting this, but I
>> should be getting back to it soon.
>> 
>> I can dig up some more details in a bit, but basically, I believe I set
>> "defaultdisplay=dvi" in U-Boot which then uses the generic LCD driver.  I
>> then used a combination of "fbset" and echo'ing timings to
>> "/sys/devices/omapdss/display0/timings"
>> 
>> According to my notes I did:
>> 
>> echo "15000,480/1/15/14,272/1/45/33" >
>> /sys/devices/omapdss/display0/timings  
>> 
>> I'd have to go back and try that again to make sure that's exactly what
>> did it, but that was the path I was on.
>> 
>> I'll try to post something more detailed later, but maybe this can get
>> you going in the right direction.  Ultimately, we need to patch the
>> driver as a workaround until the hardware issue is solved.
>> 
>> 
>> Brent
>> 
> 
> Hi Brent,
> 
> Understood. :)
> But your investigation into the timing issue do help to narrow the search
> for a permanent solution.
> 
> I look forward to more details that you can provide so that I can also try
> to solve it at my end over here.
> 
> Cheers~!
> 
> James.
> 
> 

I am trying to connect the Chestnut to a an AUO 5.7" LCD.  If I set the
pixel clock to 25 MHz (as per the AUO datasheet) then the touch panel is
very erratic and updates very slowly.  if I change the pixel clock down to
10MHz then the touch panel is much more responsive, but now my LCD is
refreshing too slow.  Could this be an electical interferrence or cross-talk
issue?  Could it help to lower the speed of the SPI bus communicating with
the ADS7846?

thanks,
Doug
-- 
View this message in context: http://old.nabble.com/LCD-touch-screen-unusable-on-Overo-Chestnut-tp30728009p32498692.html
Sent from the Gumstix mailing list archive at Nabble.com.