Chapter 6
Liquid Crystal Displays (LCDs) and mikroC Pro for PIC LCD Functions
Displays are an important part of most microcontroller based applications. A video display for example, would make a microcontroller application much more user-friendly, as it allows text messages and images to be displayed in real-time. Standard video displays require complex interfaces and are large and costly. The alternatives to video displays are the LCDs (and graphics LCDs). These devices come in different shapes and sizes. Some LCDs have only one row, while others can have up to four rows. Some have back lighting so that the display can be viewed in dimly lit conditions.
There are basically two types of LCDs as far as the interfacing method is concerned: parallel LCDs and serial LCDs. Parallel LCDs (e.g. Hitachi HD44780) are the most commonly used ones and they are connected to microcontrollers using four to eight data lines and some control lines. Serial LCDs are connected to microcontrollers using only one data line and data is sent to the LCD using the RS232 serial communications protocol. Serial LCDs are easier to use, but they cost a lot more than the parallel ones.
In this book we are interested in the parallel LCDs only, as they are the ones used commonly in display applications. In this chapter we shall be looking at the basic operating principles of these LCDs and see how they can be used and programmed in microcontroller based applications. In addition, we shall be looking at the mikroC ...
