What offset is normal on Note 8?

Discussion in 'Asus' started by mechaprimer, Mar 28, 2014.

  1. mechaprimer

    mechaprimer Pen Pal - Newbie

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    Hello,

    I recently purchased a VivoTab Note 8 and it has HORRIBLE offset all around: around 1mm (not pixel!) in the middle of the screen and increases as the stylus goes from edge to edge. I have calibrated it multiple times outside of the case, reasonably far away from magnetic fields to no avail. I have not been able to get it to work consistently in all orientations. As it is, it is difficult to even click buttons in OneNote without aiming with the hover pointer.

    During normal use, it varies between counterintuitive and extremely distracting. If I redraw a line with the stylus, I end up drawing two parallel lines instead.

    How do I fix this and how do I convince Amazon that this one needs a replacement?
     
    Last edited: Mar 28, 2014
  2. connman

    connman Scribbler - Standard Member

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    When you calibrate, are you calibrating holding the pen as you would when writing, or do you hold it straight and perpendicular to the screen?

    I had a good experience calibrating with pen perpendicular and a bad experience calibrating with pen held as though taking notes.


    Sent from my iPhone using Tapatalk
     
  3. mechaprimer

    mechaprimer Pen Pal - Newbie

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    I am holding it as vertical as I can. I have also tried it from two different viewpoints in order to see if it is due to parallax, but the results have always been the same. Also, I have done it several times by resetting the calibration completely, which makes me go through the initial 16-point calibration routine.

    Also, I tried it with the s-pen from a Note 10.1 and it was almost the same. I could not really tell if there was a significant difference or not.
     
    Last edited: Mar 28, 2014
  4. BobWerk

    BobWerk Pen Pal - Newbie

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    I would say that is normal behaviour. I also have good accuracy in the screen center, with increasing offset to the edges. The offset is especially bad when hovering. I also tried the Windows pen calibration many many times, it did get more accurate but somehow shrunk the pen-sensible area, making it stop short off the screen edges, rendering the Windows edge swipe gestures unfunctional.
     
  5. mechaprimer

    mechaprimer Pen Pal - Newbie

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    Is 1mm offset in the center with the pen down considered good accuracy? If that is so, sadly I will have to return the device for a refund...
     
    Last edited: Mar 28, 2014
  6. mechaprimer

    mechaprimer Pen Pal - Newbie

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    I might be rediscovering hot water with this post

    Ok, if anyone has similar issues and wants to achieve acceptable performance (i.e. around 0.5mm or less offset)they can try the following procedure:

    1. Calibrate the display following the proper method and using the 16-point mode (stylus vertical, outside of case, away from magnets)
    2. Note the offset in the area where you want it to work, i.e. "The cursor is about 1mm up and to the right from the nib"
    3. Calibrate again, using the 4-point calibration system. This time, tap away from the actual intersection point of the lines. Tap with the same offset that you noted previously- i.e. "1mm up and to the right" from the intersection point. This causes the software to subtract the appropriate offset and the stylus will more or less work for the area where you noted the offset. Around the edges, it will still be as bad as previously.

    Apparently, the 4-point calibration is just a linear mapping, i.e. it only scales, rotates, translates and shears the input. We are only using the "translate" part.
     
  7. BobWerk

    BobWerk Pen Pal - Newbie

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    Where is the menu to access the 4-point calibration? I can only use the 16-point method in Tablet PC Settings.
     
  8. wmadan

    wmadan Pen Pal - Newbie

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    It's the same calibration routine for pen input. It you don't choose "reset" after you conduct a 16-point calibration, the 4-point calibration is launched.
     
  9. SF6

    SF6 Scribbler - Standard Member

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    mechaprimer likes this.
  10. mechaprimer

    mechaprimer Pen Pal - Newbie

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    Thank you very much, I managed to cope with the problem by using this solution with a slightly smaller number of points.

    Code:
    tabcal devicekind=pen lincal novalidate XGridPts=10,70,120,380,640,900,1160,1210,1270 YGridPts=10,70,235,400,565,730,790
    However, there is one inconsistency in the solution: it has been made with the idea of using only a single orientation (hence the advice to hold the stylus naturally). When this is done, the offset is even worse in the other orientations. A fix (albeit not very good) is to use both the control panel utility and tabcal.exe. First, you calibrate the "lincal" data with the stylus perpendicular to the screen. This removes the nonlinearities due to the physical design of the screen, nearby speakers, etc. Then, the tablet should be calibrated for pen tilt through the control panel utility. I.e., the pen should not be vertical when using the 4 point method. This data is then saved in a per-user registry.

    So I have the following question: does anyone know how to force tabcal to record only pentilt data? I have not been able to find a solution online
     
    Last edited: Mar 29, 2014

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