This gorgeous persistence of vision clock was built a couple years back by [mb1988]. The housing is made of acrylic with a hard drive motor mounted in the center of the back panel to spin a PCB. The two-sided circuit board is home-made and includes a battery for power, ATmega32 for the brain, 32 LEDs, four display drivers, and a real time clock module. The spinning hard drive motor is nearly silent and already has threaded mounting holes on it. [mb1988] uses an optoelectric sensor to sync the display with the rate of rotation. The forum post includes download for the code and hardware details. Don’t miss the demonstration after the break.