Michael shows us how to build a mechanical 7 segment display clock using an Arduino and 28 servos:
I built a countdown timer a couple of months ago using a two digit mechanical 7 segment display which was driven by 14 servos and an Arduino Mega. It came out quite well and a number of people suggested doubling up on the display to build a clock. The only problem was that the Arduino was already running short on PWM IO and I needed to double up on the outputs. Fortunately, someone pointed me in the direction of these PCA9685 16 channel PWM drivers, so I used them and a DS1302 real time clock module to build a mechanical 7 segment display clock which uses 28 servos and is now driven using an Arduino Uno.
Project details at the-diy-life.com.
Check out the video after the break.