LinuxQuestions.org - synaptics - finger distance in two finger scrolling

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synaptics - finger distance in two finger scrolling

I'm trying to configure a Synaptics touchpad with multitouch support. I've pretty much nailed it with the synaptics manpage and synclient, however, something's not quite right:

These devices support vertical scrolling by moving two fingers on the touchpad. In a old Ubuntu version, I could (out-of-the-box) do vertical
scrolling with the two fingers close together. Now, both in ubuntu and debian, scrolling only works if they are 0.5cm+ appart.

I realize it's a bit trivial of a problem, but (right) tapping with separated fingers is especially difficult.

I've looked at EmulateTwoFingerMinW, which seems to be relevant, but it makes no difference (maybe because this is a multitouch touchpad, so it uses no emulation?). I can't seem to find any more relevant configuration, and google is failing me :mad:

I appreciate your help

What versions of Ubuntu/Debian and the driver? This work fine for me on Kubuntu 11.10 with synaptiks: 0.7.0 and synclient 1.4.1

Also ... how tiny are your fingers?! Even pressed together my fingertips are >1.0cm apart.

Quote:

Also ... how tiny are your fingers?! Even pressed together my fingertips are >1.0cm apart.

Lol! :p I can see where you're coming from.
When I mentioned "apart", i meant it as opposed to "pressed together"; 1cm+ is the distance *between* the fingers (not fingertips). So, fingers pressed together would be 0cm.
One might rephrase the problem to "I can't scroll with my fingers pressed together".

Quote:

What versions of Ubuntu/Debian and the driver?

I was using Ubuntu 11.04, if I'm not mistaken. Currently on Debian wheezy (testing).
synclient is at 1.5.0, as is the package xserver-xorg-input-synaptics. I'm not sure what's the other program you're referring to.

The other program, synaptiks, is a KDE-specific utility - you won't have that.

I can use two finger scroll with my fingers tightly pressed together ... 0.0cm separation :)

What does synclient -l show? I have no idea which setting controls multitouch scrolling but comparing your output with mine could yield a clue.

use code tags...

synclient:

Code:

Parameter settings:

    LeftEdge                = 1751

    RightEdge              = 5187

    TopEdge                = 1626

    BottomEdge              = 4306

    FingerLow              = 25

    FingerHigh              = 30

    FingerPress            = 256

    MaxTapTime              = 180

    MaxTapMove              = 222

    MaxDoubleTapTime        = 180

    SingleTapTimeout        = 180

    ClickTime              = 100

    FastTaps                = 0

    EmulateMidButtonTime    = 75

    EmulateTwoFingerMinZ    = 282

    EmulateTwoFingerMinW    = 7

    VertScrollDelta        = 101

    HorizScrollDelta        = 101

    VertEdgeScroll          = 0

    HorizEdgeScroll        = 0

    CornerCoasting          = 0

    VertTwoFingerScroll    = 1

    HorizTwoFingerScroll    = 0

    MinSpeed                = 1

    MaxSpeed                = 1.75

    AccelFactor            = 0.0394867

    TrackstickSpeed        = 40

    EdgeMotionMinZ          = 30

    EdgeMotionMaxZ          = 160

    EdgeMotionMinSpeed      = 1

    EdgeMotionMaxSpeed      = 405

    EdgeMotionUseAlways    = 0

    TouchpadOff            = 0

    LockedDrags            = 0

    LockedDragTimeout      = 5000

    RTCornerButton          = 0

    RBCornerButton          = 0

    LTCornerButton          = 0

    LBCornerButton          = 0

    TapButton1              = 1

    TapButton2              = 3

    TapButton3              = 2

    ClickFinger1            = 1

    ClickFinger2            = 3

    ClickFinger3            = 2

    CircularScrolling      = 0

    CircScrollDelta        = 0.1

    CircScrollTrigger      = 0

    CircularPad            = 0

    PalmDetect              = 0

    PalmMinWidth            = 10

    PalmMinZ                = 200

    CoastingSpeed          = 20

    CoastingFriction        = 50

    PressureMotionMinZ      = 30

    PressureMotionMaxZ      = 160

    PressureMotionMinFactor = 1

    PressureMotionMaxFactor = 1

    GrabEventDevice        = 1

    TapAndDragGesture      = 1

    AreaLeftEdge            = 0

    AreaRightEdge          = 0

    AreaTopEdge            = 0

    AreaBottomEdge          = 0

current xorg.conf:

Code:

Section "InputClass"

        Identifier      "Touchpad"

        MatchIsTouchpad "yes" 

        Driver          "synaptics"

        Option          "TapButton1"            "1"

        Option          "TapButton2"            "3"

        Option          "TapButton3"            "2"

EndSection

Quote:

I have no idea which setting controls multitouch scrolling but comparing your output with mine could yield a clue.

It's both the scrolling and two finger tapping, so I think it wouldn't be a scroll specific option.
I'm not sure if X somehow autoconfigures the driver options...

Comparing has not yielded any clues :(

This is what I get:

Code:

Parameter settings:

    LeftEdge                = 53

    RightEdge              = 1099

    TopEdge                = 48

    BottomEdge              = 720

    FingerLow              = 24

    FingerHigh              = 29

    FingerPress            = 255

    MaxTapTime              = 180

    MaxTapMove              = 59

    MaxDoubleTapTime        = 180

    SingleTapTimeout        = 180

    ClickTime              = 100

    FastTaps                = 0

    EmulateMidButtonTime    = 75

    EmulateTwoFingerMinZ    = 280

    EmulateTwoFingerMinW    = 6

    VertScrollDelta        = 27

    HorizScrollDelta        = 27

    VertEdgeScroll          = 1

    HorizEdgeScroll        = 1

    CornerCoasting          = 0

    VertTwoFingerScroll    = 1

    HorizTwoFingerScroll    = 1

    MinSpeed                = 1

    MaxSpeed                = 1.75

    AccelFactor            = 0.1468

    TrackstickSpeed        = 40

    EdgeMotionMinZ          = 29

    EdgeMotionMaxZ          = 159

    EdgeMotionMinSpeed      = 1

    EdgeMotionMaxSpeed      = 108

    EdgeMotionUseAlways    = 0

    TouchpadOff            = 0

    LockedDrags            = 0

    LockedDragTimeout      = 5000

    RTCornerButton          = 2

    RBCornerButton          = 3

    LTCornerButton          = 0

    LBCornerButton          = 0

    TapButton1              = 1

    TapButton2              = 2

    TapButton3              = 3

    ClickFinger1            = 1

    ClickFinger2            = 1

    ClickFinger3            = 1

    CircularScrolling      = 0

    CircScrollDelta        = 0.100007

    CircScrollTrigger      = 0

    CircularPad            = 0

    PalmDetect              = 0

    PalmMinWidth            = 9

    PalmMinZ                = 199

    CoastingSpeed          = 20

    CoastingFriction        = 50

    PressureMotionMinZ      = 29

    PressureMotionMaxZ      = 159

    PressureMotionMinFactor = 1

    PressureMotionMaxFactor = 1

    ResolutionDetect        = 1

    GrabEventDevice        = 1

    TapAndDragGesture      = 1

    AreaLeftEdge            = 0

    AreaRightEdge          = 0

    AreaTopEdge            = 0

    AreaBottomEdge          = 0

And your options don't seem to have an effect on the problem here.
Ah well, I guess I'll start using the keyboard...

Thank you for all your help, SecretCode! :)

I was just trying to solve this problem on a Debian 8 install. I found that the key values to tweak are EmulateTwoFingerMinZ and EmulateTwoFingerMinZ. This command worked well for me, but your exact values vary:

Code:

synclient EmulateTwoFingerMinZ=47 EmulateTwoFingerMinW=0

this archwiki article has been invaluable for me:
https://wiki.archlinux.org/index.php/Touchpad_Synaptics