This Large Digit Display unit was originally designed for use with the Ginormous Stopwatch module presented in Part 1 last month. It has 178mm (7-inch) characters and can use high brightness LEDs for dazzling daylight performance.

It can also be driven from a standard computer serial port with the optional adapter, allowing it to be used as a scoreboard, bingo number display, clock, etc.

The heart of the circuit is a PIC16C54 microcontroller, which receives and processes serial data from the Stopwatch module or computer serial port. The data reaches the micro via an opto-isolator, as discussed in Part 1, and the individual digit modules can be daisy chained together up to a maximum of 16 modules.