This webpage describes a simple technique to display characters from both internal character generator and user designed chracters on an LCD. The Hitachi HD44780U or a compatible controller is used here in 8-bit interface mode. The program code given here defines the custom characters and loads it into the character generator RAM (CGRAM).
Output on HD44780U display driver compatible 16x2 LCD
The first line of the LCD contains inbuilt characters. The second line of the LCD contains user defined custom characters.
find more www.lcdinterfacing.info