We use an USB based capacitive touch in aT20 (WEC7) based device. The same touch and the same display is used in an other X86 based application under Windows Embedded 7.
The manufacturer of the touch calibrates the touch for the X86 application and the calibration data are stored in the controller of the touch (NOT in the X86 device). A calibration in the X86 based device is not necessary.
If we use the touch in the T20 based device under WEC7 we must recalibrate it.
Why is this necessary?