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Touch screen X,Y axis inversion RRS feed

  • General discussion

  • My company has a device composed of a touch screen, monitor, and a special function control surface. The touch screen axis are inverted in X and Y with respect to the graphic on the monitor. This is not a new or unexpected configuration and can be detected during calibration. When this device is connected to our Linux/embedded system, calibration detects the inversion, does the math, and maps the device to the region of desktop overlayed by the touch screen and gets the direction correct. 

    In Windows 7/8, we can plug this touch screen and monitor into a workstation, stretch the desktop over the monitor, associate the touch device to the monitor via calibration in control panel. In fact, my setup has two monitor both overlayed with a touch screen. I know in fact that this device has X and Y inverted. I go through the long calibration procedure for the inverted device and get odd results when touching and dragging on the screen.  If I ignore the exact location of the prompt in calibration and provide input from the inverted location, the touches work exactly as you expect: all inverted but in relatively correct locations. 

    This is an HID multi-touch screen from MosArt. The reason that the X,Y axis are inverted is because the monitor is in fact mounted upside down for view angle purposes. However, the video signal is inverted in h/w, not software, so the system is unaware that the graphic was inverted. This is the reason why these touch screens' axis are inverted. 

    Now, I have to solve this. First, why doesn't windows just handle inversion correctly? Is there a way in indicate this configuration? Is the information of axis orientation buried in the HID report? If so, can I filter the report and provide the information correctly? Do I need to write a driver to handle the inversion? If so, what is the simplest type?

    Thanks in advance,

    Donald

    Monday, February 4, 2013 5:53 PM

All replies

  • Answer is to write a filter driver for device. I have done so. Windows development called the inability to handle inversion or swapping of axes as a limitation.
    Friday, October 31, 2014 4:33 PM
  • how about rotate the monitor by 180 ?
    Wednesday, May 24, 2017 10:41 PM