Messages in this thread | | | Date | Thu, 18 May 2006 16:38:24 +0200 | From | Harald Welte <> | Subject | Re: How should Touchscreen Input Drives behave (OpenEZX pcap_ts) |
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On Thu, May 18, 2006 at 01:16:16PM +0200, Florent Thiery wrote: > > > As of now, I return > > X_ABS, Y_ABS and PRESSURE values between 0 and 1000 (each). > > > Are you kidding ??? Does the touchscreen support pressure sensitivity? > Normally it wouldn't, you'd have only two values... Because > sensitivity touchscreens really are rare... That's why wacom does > use the pen to report pressure info on their tablets
No, this touchscreen actually has fairly reasonable pressure reporting. I know that this is unusual. But I get reproducible numbers when trying soft stylus press, hard stylus press. And things like finger touching. Also I can actually distinguish a thumb from an index finger press ;)
> >1) where does touchscreen calibration happen? The EZX phones (like many > > other devices, I believe) only contain resistive touchscreens that > > appear pretty uncalibrated. I'm sure the factory-set calibration > > data must be stored somewhere in flash, but it's definitely handled > > in the proprietary EZX userland, since their old kernel driver > > doesn't have any calibration related bits. > > > I would say touchscreen calibration = scaling (to resolution) + reference points
see the other comments. apparently that is left to userspace.
> I would say the best would be to watch pressure evolution.... If it > springs from 0 to 400 in less than sotg like 200 ms, then you got the > "button" event. Is it feasable?
that would require rerlatively small polling intervals. please note that the hardware generates interrupts when pressure != 0. We could start a high-granularity timer
> I got a question: does stylus usage on original A780 show the pressure > sensitivity?
not that I've ever noted. But Motorola ignores many of the hardwares capability..
> Another one: you say you're workin on building X-e. Are you talking about kdrive?
I have no idea, just replaying the package names that OE uses ;)
I now have Xfbdev running on the A780. Unfortunately due to some strange black magic, the ts driver ceases to receive interrupts as soon as X is started. reproducible. The same happens with ts_test.
ts_print works very good, though.
Will do more debugging
-- - Harald Welte <laforge@gnumonks.org> http://gnumonks.org/ ============================================================================ We all know Linux is great...it does infinite loops in 5 seconds. -- Linus [unhandled content-type:application/pgp-signature] | |