• AVR Freaks

Touchscreen Calibration Methods

Author
PIC
Senior Member
  • Total Posts : 151
  • Reward points : 0
  • Joined: 2008/04/26 17:02:13
  • Location: 0
  • Status: offline
2008/10/24 17:02:21 (permalink)
0

Touchscreen Calibration Methods

Hello,

I came across this article for touchscreen calibration. What other methods are possible for touchscreen calibration?

Thank you

#1

3 Replies Related Threads

    tony4l
    Super Member
    • Total Posts : 473
    • Reward points : 0
    • Joined: 2003/11/07 12:36:16
    • Status: offline
    RE: Touchscreen Calibration Methods 2008/10/31 02:36:59 (permalink)
    0
    actually I just implemented the method suggested in the article in a dsPic33 and I'm impressed at how accurate it works.

    There might be simpler methods for calibrating though they would depend on certain premises as to how accurate your touch foil is mounted on the screen. So, for instance, I hold it conceivable to simplify the method if you assume that you do not have any rotation but only translation & scaling. In that case, you can simply try and sample two points (e.g. top left, bottom right) and simply interpolate x and y values.

    HTH,
    Tony

    beware of ASCII characters when posting. better safe than sorry!
    #2
    jgmartinez
    Super Member
    • Total Posts : 537
    • Reward points : 0
    • Joined: 2007/06/28 06:13:39
    • Location: Madrid, Spain.
    • Status: offline
    RE: Touchscreen Calibration Methods 2008/11/15 04:43:46 (permalink)
    0
    It is function of how acurate touch is need. If touch screen is mechanically attached to display so the rotation error is minimal and always (production line) the same, then a simple method is to calibrate the four corners. Then any position in between is calculated by a simple equation y = ax + b were a and b were calculated from calibration procedure.

    The calculated values are then, for 4 wires system:
    X = Ax * Voltagex + Xoffset
    Y = By * Voltagey + Yoffset



    Juan Pablo
    EA4CIV
    #3
    man_of_steel
    New Member
    • Total Posts : 18
    • Reward points : 0
    • Joined: 2013/06/17 01:54:03
    • Location: 0
    • Status: offline
    RE: Touchscreen Calibration Methods 2013/06/18 05:21:50 (permalink)
    0
    hello,
    please tell me, how to calibrate the microchip touch screen.
    I have downloaded simple action, but not able to calibrate the touch screen.
    thank you
    #4
    Jump to:
    © 2019 APG vNext Commercial Version 4.5