“John Boxall” design and build this clock that has no digits. It displays time by blinking each digit in different color using an RGB led. Clock is being run from an ATmega328 Microcontroller and a DS1307 Real Time Clock. Check design files and schematics in the link below. [via]
For example, if the time is 12:45, the clock will blink red 12 times, then show blue for a second (think of this as the colon on a digital clock) then blink four times in green (for forty minutes), then blink three times in red for the individual minutes. If there is a zero, blink blue quicklyl.
RGB LED Blink Clock – [Link]