This pendulum POV clock uses a Nixie tube to plot the time as it swings

Clock pendulums are generally mechanical devices that time each second as it ticks away, but do little else. Jason Oeve’s concept, however, places the face itself – a single IN-12B Nixie tube – onto its large wooden pendulum. As it swings back and forth, four digits are progressively displayed on the tube for a unique timepiece.

An Arduino Nano is the brains of the operation, along with an RTC module and an accelerometer that senses the pendulum’s position. When it’s straight up and down, an electromagnetic coil gives it a boost, keeping it ticking along “forever.”

You can see it in action below and find more info on the project’s write-up.