Driving a Character LCD using PIC24 Enhanced Parallel Master Port

Traditionally, Toshiba HD44780-compatible alphanumeric LCD displays are driven by bit-banging bus signals combined with long delays between sending commands and data. In many cases, this method is good enough. However, there are situations where extra CPU cycles are not available, and a more efficient method of driving the display is needed. I’m currently working on a design involving very fast USB exchanges combined with occasional LCD output, and I’ve developed a solution that works very well for me. I’m sharing it in the hope that fellow developers will find it useful.