ABSTRACT

This chapter shows that programming liquid crystal displays and interfacing the liquid crystal displays (LCD) with the PIC 16f84 microcontroller. LCDs are one of the most used devices for alphanumeric output in microcontroller-based circuits. The chapter discusses parallel-driven LCD devices based on the Hitachi HD44780 character-based controller, which is by far the most popular controller for PIC-driven LCDs. Most LCDs used in microcontroller circuits are equipped with the same controller, the Hitachi HD44780. This controller provides a relatively simple interface between a microcontroller and the LCD. Some LCDs are equipped with a LED backlight so as to make the displayed characters more visible. Some manufacturers wire the backlight directly to the LCD power supply, while others provide additional pins that allow turning the backlight on or off independently of the LCD display. LCD initialization depends on the specific hardware in use and on the circuit wiring.