Microcontroller drives LCD with just one wire

摘要

HD44780 LCDs are the most popular alphanumeric displays in embedded systems. The only downside is that they use six I/O pins in 4-bit nibble mode and as many as 11 pins in 8-bit mode. Earlier Design Ideas have described many approaches to saving or expanding I/O pins (references 1, 2, and 3). In driving an HD44780-compatible LCD, it would be better to use a baseline microcontroller instead of logic chips, because the microcontroller is lower cost, uses less board space, and has programming features. Microchip has introduced the smallest PIC 10F microcontroller family, which comes in a six-pin SOT-23 package.