Behind the clock is an Arduino driving a MAX7219 LED controller. Using the MAX7219 was a challenge because it expects a grid of LEDs while the clock needs a linear array.

Learn how to control and blink multiple LEDs using the MAX7219 driver with Arduino. A simple guide for beginners in ...

The display uses two MAX7219 LED drivers to control the grid which is build on a big hunk of protoboard. An Arduino ties the whole system together with a Chonodot for accurate time keeping.

The MAX7219 driver simplifies the process of controlling multiple LEDs in matrix or numeric display form. For fast prototyping, software code developed for the MAXREFDES99# reference design works with ...