Displaying information is one of the crucial steps in electronic projects. So using LCDs has always been one of the most popular ways to display information. LCD modules designed as the most prominent as they are low cost and program friendly, hence these modules are commonly used in the embedded system. These are big character LCD display modules line up of 20*4 characters with black characters on the green backlight. It uses an extremely common ST7066U LCD driver IC. These 20*4 LCD are available in STN or FSTN LCD modes with or without backlight. This module provides a wide viewing angle and high contrast to the display.
20*4 LCD module consists of 20 columns and 4 rows, so it has 80 (20*4) characters in total. Each character has 40 pixels (5*8). A built-in controller IC JHD629-204A same as LCD controller IC is ready to interface with most of the microcontrollers. It is a parallel interface in which 7 pins for 4-bit and 11 pins for 8- bit mode is required to interface the LCD module. LED backlight can be dimmed easily with a resistor or PWM. This display module works on 5V and has a green backlight and also can be on or off as per requirement. In this, each LCD requires a controller to execute its internal operations. This character graphical LCD can displays alphanumeric as well as graphics also, thus it is highly suitable in animations.