This example is based on a LCD module with the Hitachi HD44780 LCD-controller.You can get these displays in various kinds, from 1 to 4 lines and from 8 to 40 characters per line.
A display with 16 characters per line and 2 lines is used in this example. The display uses a power supply of 5V DC. The LCD controller can accept 8 bit data bytes or 4 bit nibbles. In this example the 4-bit mode is used. There are more to find on the internet. But I wanted to make my own 4-bit LCD interface, to develop my skills in C-programming.
Schematic and build
The interface uses the 4-bit mode of the LCD so you need only one port. Here PORTB is used, but you can use any other port.
See the schematic below.
Software
To make the software code is build with the WINAVR compilier.
The program can be adapted to use another port. The program can write instructions and data to the LCD controller. There are also functions to control the display and to write text string to the LCD.
Read more: LCD interface