THE MAGAZINE FOR COMPUTER APPLICATIONS
Circuit Cellar Online offers articles illustrating creative solutions
and unique applications through complete projects, practical
tutorials, and useful design techniques.

LOOKING GOOD

Using a Graphics-Based LCD
Module with C
by Bob Perrin and Tak Auyeung

Start ý Software Overview ý The Bottom Layer ý Initializing the LCD Display ý Shadow Display ý Drawing Dots and Lines ý Printing Text ý Extensions ý Sources and PDF

EXTENSIONS

The driver discussed in this article is a good start for many applications. Interesting extensions include functions that perform the following tasks:

There is also room for efficiency improvement in the implementation of the driver code. Rewriting in assembly can further optimize some code (especially the bit-banging code). Specialized cases can improve the efficiency of some C code.

WRAPPING IT UP

For this article, we put together a system of simple hardware and portable C code that allows a graphics-based LCD to be driven from an embedded controller. The schematic in Figure 1 and the code in glcd.c and glcd.h can be used freely as is or adapted for your application.

Using a graphics LCD is a bit more complicated than using a simple bit-mapped LCD module, but with a little work at the driver level, software can abstract the difficulties from the application. If your next project can benefit from a graphics-based display, you now have the basics required to design one into your system.

PREVIOUS • NEXT

Circuit Cellar provides up-to-date information for engineers. Visit www.circuitcellar.com for more information and additional articles.
For subscription information, call (860) 875-2199, subscribe@circuitcellar.com or subscribe online. ýCircuit Cellar, the Magazine for Computer Applications. Posted with permission.