This pendulum clock is not only regulated by the pendulum, but it is driven by it. A hidden magnet in the pendulum swings past a hidden coil and induces a current. This is detected and then a current pulse is fed into the coil, creating an electromagnet that repels the pendulum to keep it moving.
Others have designed and built clocks like this, but as far as I know mine is the only one using a microcontroller to fine-tune the pendulum's speed to keep accurate time.
The coil's output is filtered and fed into an MSP430 comparator, set on an interrupt to wake the microcontroller up. T