XX is the number of the option. In this example 13=movfilter.
YYY is the value you want to set. In this case 46. You must use 3 digits.
set_touchscreen is the file where you store this information. It's not always set_touchscreen, it could also be set_noise, set_acquisition etc...
To apply the changes you have to run this:
To get the new configuration run
This will output a lot of kernel messages, not only the touchscreen configuration.
If you want to get the default configuration: reboot, 'cat /sys/touchscreen/set_write' and then 'dmesg'.
The touchscreen maximum scan speed of the AT42QT602240 it's 250Hz for 1 finger (one scan every 1/250 s --> 4ms per scan)
so it will always have delay while moving, maybe you can improve it to some extent but it's slow compared to rapid movements that can be made while drawing, but for normal use, it isn't noticeable.
I also want to add that the controller chip 4ms isn't final, the response that the microsoft research team it's showing it's for the whole loop (finger detected > drawed point on screen) and for that a lot of other times are need to take in account, for example screen refresh rate of our device (and most) takes about 17ms (60hz), so there is a need to improve hardware on the forthcoming devices.
Probably I didn't explain what I mean well enough. Let's try this:
Put your finger on the screen and try to move it changing the coordinates of a single digit, not three, not five, just one. It's better if you do this in a single direction, try to keep still the X or the Y.
I doubt you can do this. And do this right after you put the finger on the screen, not after the coordinates already changed, becase after that the hysteresis automatically changes.
I know the change is instant even without this patch, I'm not talking about centimeters, inches (or whatever you use) and it's not to be intended in terms of time. I'm talking about pixels. This change is nothing revolutionary, we can't improve our hardware. Moreover the value that make me feel the change was movfilter, but in some situations the screen was hard to use, so I put back the original value.
I'm suggesting to remove the hysteresis because I think that every app applies a sort of movement filter that is coupled with it. With the updated values I can easly keep the screen still with my finger on it (with the first ones there were some microscillations).
Does anyone know why the screen sensitivity changes while plugged in?
The TSP thresold is intentionally increased, I don't want to change this, it's just a curiosity, because I couldn't find any exhaustive explanation.
How did you get the first configuration file ??
how can I view the current configuration ??
Oh, I forgot to add this info.
The first command set the current configuration and then use printk() to show it. To see "printk()" messages, you have to use the second command (dmesg). This will print a lot of kernel messages, not only the touchscreen configuration.
Originally Posted by vivekkalady
what do this improvement does ?
It's like changing brightness/colours of your screen. There's no real improvement, it's up to you. I showed you a way to configure your touchscreen.
is it multitouch?
I don't understand what you mean.
You can change the number of finger tracked by the screen if you want (default 5, numtouch).
Originally Posted by vivekkalady
what is movfilter ???
A parameter I used in the example above.
If you want to know what's its effect, well, try to change it.
Basically it changes how the screen reacts to movements. If you set it to a very low value, scrolling becomes very hard, the screen is like immovable.
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