Using LEDs, LCDs and GLCDs in Microcontroller Projects

7.6 Adding Touch-screen to GLCDs

More and more consumer electronic products are now available with touch-screen inputs. For example, electronic games, MP3 players, GPS receivers, mobile phones, PDAs, ATM machines, industrial control systems, remote control devices, point-of-sale (POS) terminals, advertisement show screens, information displays, and many more similar products offer special screens where items are selected from a menu by simply touching the relevant part of the screen.

Perhaps the biggest advantage of a touch screen display is that it eliminates the need for keyboard input, resulting in a cheaper and lighter overall design. The user input facilities in such devices are usually provided in the form of soft keypads, where the layout of a keypad is displayed on a touch-screen panel, and the required characters and numbers can be entered by simply touching the required key positions on the touch screen. A soft keypad also makes it easier to enter and edit data quickly.

Another advantage of a touch-screen display is that it is usually much quicker to navigate around the screen than using a keyboard or mouse type inputs. Also, in some applications, such as GPS mapping and navigation, a desired geographical point can easily be selected by simply touching the desired point on the screen. It may take more time and effort to accurately select a point on a map using a keyboard and a mouse.

Touch-screen displays are also used in most POS systems, for example in restaurants and ...