Re: [DIGImend-users] Bizarre Tablet Issue

[Nikolai K. <sp...@gm...>]

Hi Zauber,

I'm CCing your message to the DIGImend mailing list, so that other users
could see it. Please reply using "Reply to all".

On Mon, Apr 2, 2012 at 5:42 AM, Zauber Paracelsus
<zau...@gm...> wrote:
> I've got a UC-Logic tablet, and I've been having some VERY bizarre
> issues with it.  I've got a dual-monitor setup (both widescreens), and
> I followed the instructions for setting the coordinate transformation
> matrixes up, as shown in this forum thread:
>
> http://ubuntuforums.org/showthread.php?t=1656089&page=4
>
> However, any time any of these settings are changed, they apply
> correctly, but the tablet begins having issues:  the cursor's
> X-position keeps going to zero and snapping back at random.  The link
> below is for a snapshot of my attempt to draw a straight vertical line:
>
> https://lh4.googleusercontent.com/-uzqvoPIhJEU/T2QEt1hA6GI/AAAAAAAACJo/RwIm_4jAoLg/s642/AttemptedStraightLine.png
>
> This all happened about two weeks ago, at which point I gave up for the
> time being.  But, I still want to try and get this working, without
> some sideways workaround (like using a VNC-connected laptop for it).
>
> In the end, Favux recommended I speak with you, so I'm wondering if you
> can help me fix it, or at least debug it so that the source of the
> problem can be figured out.

This might be an xf86-input-evdev issue. Still, let's check that it's
getting correct data.

Once the issue is showing well again, could you please try capturing "sudo
evtest" output for your tablet, while you move the pen inside a small area
within the center of the tablet (so that jumps could be more obvious)?

If evtest complains that it can't grab the device, please switch to a text
console and execute "sudo evtest" there.

Evtest will show you two devices for your tablet - one for the pen, one for
the mouse you don't have. The mouse device will produce no output when
moving the pen, please run evtest with the other one.

Please send me the output. If it shows no jumps, then I'll try to reproduce
the issue and will look into the xf86-input-evdev source. Otherwise, we will
try to check if it's a hardware issue.

BTW, under which name was your tablet sold?

Thank you.

Sincerely,
Nick