BUILD THE PI SCROLLING

摘要

I like the look of seven-segment LED displays and came up with a couple of fun applications for them: a scrolling display of the digits of pi (3.14159...) and my own desktop version of the National Debt clock.The five-digit Freescale MC14489 can be daisy-chained to support displays of more than just five digits, so I settled on stringing three of them together for a 15-digit display. This is long enough to give a pleasing appearance when scrolling, and to display all the digits of the national debt (at least for now).This is a versatile system which can be adapted to plenty of other uses, too.