Re: [H2200-port] h2200 : opie vs gpe - inaccurate screen taps

Hello Michal,

Tuesday, March 6, 2007, 2:13:49 AM, you wrote:

> Hi all !

> A while ago Icebird has reported it but I have not found any solution
> for that - comparing Opie vs GPE it occurs that somehow screen taps
> are accurate in GPE (smooth, no problems ) and Opie is the queen (king
> ? I don't know :P) of inaccuracy.

  Well, that's somewhat strange - both GPE and OPIE obviously use the
same hardware driver, plus both of them route thru tslib which apparently
must have the same config.

> A simple example: these are results
> of the same screen tapping in a drawing pad/sketch book.
> GPE: http://delta-9-thc.czuby.net/~yans/hh/photos/gpe_h2200.png
> OPIE: http://delta-9-thc.czuby.net/~yans/hh/photos/opie_h2200.png
> I was just tapping around the screen and making a cross - just like
> can be observed in GPE image. The Opie's one has (in some cases) lines
> instead of just points. I guess all the OPIE users understand what I
> am saying.

> Can somebody tell me what is causing that (pls - don't say "your
> hands" :P) or even better if there is a solution for that ? As far as
> I remember in the 0.8.4-rc3 it worked (at least) ok, so I guess it can
> be eliminated.......

  I saw such pattern with h4000 while developing generic TS driver
(ts-adc-debounce): when lifting pen, there was stray random reading,
which causes all those strokes. The solution is of course to detect
"pen up" condition properly. One good way for that is to write generic
ADC driver for hamcop, and use ts-adc-debounce's capabilities. Err, I
lie - join in with its tweaking so it can actually serve any handheld
out there. So far, only h4000 & hx4700 work perfectly, magician and
aximx50 have issues. It seems that aximx50 has close issue, which is
being reported as "calibration off by few centimeters". Unfortunately,
there're no such good screenshots, so it's hard to tell.

> Cheers
> Michal

-- 
Best regards,
 Paul                            mailto:pmiscml_at_gmail.com