Knowledge Base

You can get the HMI430/700 to display crosshairs on the screen that show where it is being touched.

This can be useful in verifying the touchscreen is calibrated correctly and can be even more helpful in determining if the bezel surrounding the LCD is accidentally pressing on the screen.  This is catastrophic as a resistive touch screen relies on pressure to detect a touch and can only recognise one point of force.  So any part of the housing pressing on the screen will render the touch useless.

To turn on the crosshairs, simply execute this code:


SetU 0,1 ;show the..
SPxCmd1 0,10 ;..touch point

To turn off the crosshairs, execute this code (or powercycle):


SetU 0,0 ;hide the..
SPxCmd1 0,10 ;..touch point