Arduino Pendulum Clock 2

Arduino Pendulum clock. This is a true pendulum clock in that the pendulum keeps time, not the arduino. The purpose of the arduino is to simply keep the pendulum perpetually moving. (same purpose a the main spring in a traditional clock) This uses a magnetic coil that I hand wound myself and a hall effect sensor to tell the arduino when the pendulum is at the bottom center of each swing. The arduino gives the pendulum a tiny magnetic push via the coil in the base and a magnet on the bottom of the pendulum.
The accuracy of this clock is surprisingly good, just a few seconds off per day so far (I'm still finely adjusting it) This is the 2nd arduino pendulum clock I've built.