Liquid crystal displays (LCDs) offer a convenient and inexpensive way to provide a user
interface for a project. This chapter explains how to connect and use
common text and graphical LCD panels with Arduino. By far the most
popular LCD is the text panel based on the Hitachi HD44780
chip. This displays two or four lines of text, with 16 or 20
characters per line (32- and 40-character versions are available, but
usually at much higher prices). A library for driving text LCD displays
is provided with Arduino, and you can print text on your LCD as easily
as on the Serial Monitor (see Chapter 4),
because LCD and serial share the same underlying
LCDs can do more than display simple text: words can be scrolled or highlighted and you can display a selection of special symbols and non-English characters.
You can create your own symbols and block graphics with a text LCD, but if you want fine graphical detail, you need a graphical display. Graphical LCD (GLCD) displays are available at a small price premium over text displays, and many popular GLCD panels can display up to eight lines of 20 text characters in addition to graphics.
LCD displays have more wires connecting to Arduino than most other recipes in this book. Incorrect connections are the major cause of problems with LCDs, so take your time wiring things up and triple-check that things are connected correctly. An inexpensive multimeter capable of measuring voltage and resistance ...