March 20, 2013 Posted by: Dr. Ace Jeangle
How to calibrate N-Trig touchscreen
Normally, capacitive touchscreen does not require calibration like resistive. This is because capacitive touchscreen has grid of sensitive tracks on panel surface and can get exact information about finger position. But because detection is based on measuring of changed capacity of surface, therefore sometime it can require calibration of sensitivity. Some of our customers noticed that cursor can behave like crazy when you touch screen (and sometime even without any touch). This can happen when touchscreen controller has increased sensitivity, and it responds to any change of capacity nearby of screen surface and touch controller itself. We know that most of you use this panel right on your workbench full of turned on equipment, powered wires and cables, always turned on solder station – I have exactly the same situation on my desk, so I know it for sure 🙂 In such cases we propose to do the following:
- First of all, take into account that any capacitive touchscreen requires to be placed inside enclosure. This will eliminate most problems with phantom mouse shakes and clicks.
- If you use it without enclosure, then please take care to remove any EMI emitting equipment, connected/powered wires, unbalanced fluorescent lamps, etc. as far away from touchscreen as possible. At least nothing should be under green PCB of touchscreen controller on the bottom side of LCD panel.
- Next is power supply. Check that your power supply provides clean 5V signal on its output. We also recommend to use UPS or good power filter on AC side.
- Finally, you can use special Windows tool to calibrate screen sensitivity to your current environment. Here is link to calibration utility: http://goo.gl/TLK4P. You should connect your panel to Windows PC, use only USB – others connectors are not required. Then run this program, it should find panel, then will ask you to not touch panel during calibration (calibration does not require any interaction with touch surface during whole procedure)