MicroTouch Micro Touch Capacitive Controller MT3000, Reference Manual, Page: 36 / 64

MT3000 Capacitive Controller Reference Guide 36
Calibrate Extended
Syntax:
<SOH> CX <CR>
Description:
Initiates an interactive, two-point calibration.
During the calibration process, you define the active area of the touchscreen
by mapping locations to an absolute X/Y coordinate system. You touch two
target areas on the screen. Touching the target areas sends the X/Y
coordinates for those touch points to the controller. The controller
calculates all other touch points based on these two points.
The Calibrate Extended command sets the calibration targets (points)
inward from the corner of the video image. Setting the targets inward makes
the calibration process easier and more accurate.
Determining Target Areas
The default calibration targets (points) are located 12.5% (1/8) inward from
the corners of the video image.
For example, suppose the display resolution of your monitor is
1024 x 768. The Calibrate Extended command calculates the amount to
move inward as follows:
•
Amount to move inward in the X direction: 1024 x 1/8 = 128
•
Amount to move inward in the Y direction: 768 x 1/8 = 96
The Calibrate Extended command then positions the first calibration target
inward from the lower left corner (0,767) and the second calibration target
inward from the upper right corner (1023,0). The following illustration
shows how the calibration targets are calculated.