Analog wall clocks normally use a quartz crystal and some electronics to generate pulses that drive a tiny actuator that ticks the clock on by a second. The movement of the minute and hour hands uses gears to make them turn at the correct rate. With a bit of care, you can hack the clock so that the pulses are generated by an Arduino (Figure 24-1).
FIGURE 24-1 Hacked analog clock.
This idea was introduced to me by Esa Pollari. Many thanks to him for developing this excellent idea.
This project is compatible ...