POV clock inside acrylic block

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.

[Thanks Tehgringe]

25 thoughts on “POV clock inside acrylic block

  1. He doesn’t use a battery, there is a track on the bottom side that he uses with a contact to make a slip ring. I’m guessing that ground is done through the screws into the motor.

    This is definitely one of the best POV clocks I’ve seen so far.

  2. Wow, the mechanical balance of that pcb is obviously perfect. That makes me wonder about the effect that spinning would have on the components over time. If they moved the balance could change resulting in disaster. Not to be a downer. Too nice to look at. What RPM is it running at I wonder.

  3. I love POV devices, but I could never have one in my house. I’ve never come across one that didn’t produce a lot of noise. Sure, during the day it may not sound loud, but at night when you are tying to sleep they are just too loud.

  4. I built a regular HDD POV clock, but the mainboard crapped out and quit driving the motor. For lack of appropriate parts and motivation, I just shelved it until I could get some kind of easy to use motor driver.

    I was hoping that the TDA5140A that he used could revive it, but alas, it looks like it’s not manufactured anymore. Anyone know of an alternative all-in-one solution for driving a BLDC motor? I know I can do it with an MCU and some discrete components, but this chip is just so perfect for this sort of application.

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