Adjusting PiFace Control And Display LCD contrast

If you have tried to write text to your PiFace CAD LCD screen and nothing happens, but you know its working because you can turn the backlight on, it is likely that you will need to adjust the contrast screw.

PiFace CAD contrast screw circled in red
PiFace CAD contrast screw circled in red

Using a very small flat or plus head screwdriver, turn the screw until your text has appeared dark black on the screen, but without the background appearing black as well.