For a word clock, it’s ... The 8×8 limitation was initially set because he wanted to use a low-cost MAX7219 8×8 LED matrix module ... Both use an ESP-01 and an Arduino to help drive ...

The idea here is to use a cheap clock from IKEA, wire in a bunch of LEDs, connect and Arduino, and then use the 1Sheeld to trigger color changes depending on the traffic time between two points.

If you’re dealing with RF, you’ll probably have the need to generate a variety of clock signals. Fortunately, [Jason] has applied his knowledge to build a SI5351 library for the Arduino… ...

Build Your Own Arduino-Based Laser Clock with a Salad Bowl, Laser Pointers, and Some Spare Time. Alan Henry. March 5, 2012 ...