Typical microcontroller projects generally require user output. Individual LED's or similar can provide visual feedback (e.g., a particular function and or input/output is active or inactive) and seven-segment LED displays offer the ability to denote alphanumeric information (e.g., digits for a numerical display). However, the now ubiquitous Hitachi HD44780 LCD controller is an alphanumeric dot matrix liquid crystal display (LCD) controller that enables easy display of multi-line text (typical formats 16 chars x 2 lines, 20 chars x 2 lines).
The HD44780 LCD controller (available since 1987) is now superceded in commerical products (1), but is widely used in DIY projects due to the ease of use and now low cost. Although now even in DIY projects parts such as the Nokia 5110 84x48 LCD module are replacing the HD44780 LCD controller due to equivalent cost and more flexibility in the Nokia 5510 raster display enabling graphics and not just alphanumeric text.
A 16x2 LCD serial module (compatible HD44780 LCD) is interfaced to a PIC18F248 microcontroller and CCS C code is used to display received data from a connected PC via RS232 connection.
See the various sections below for circuit details, schematic diagrams, software/firmware and other details.