This work is based off the work of two other individuals that did an excellent job of paving the way for my project. Author:vishnubob http://www.instructables.com/id/Hard-Drive-Persistence-of-Vision-HDPOV/ His work was ...
His work was based off Ian Smiths version of the same type of clock.
Using vishnubob’s instructable I began creating a Hard Drive POV clock. Once I had the basic design completed I ran into a few things that I wanted to change. The first was that the platter rotated at 7500RPM & with a slit cut into the aluminum platter it made a good deal of noise. The second thing was a python script running on the PC provided the time to the arduino, I wanted something that is standalone.
What I did to solve the speed problem I used a 3-Phase ESC connected to an arduino, the program maps the potentiometer value to a value between 0 & 180. Using the servo library I can then send that value to the ESC to control the hard drive rotation speed. This helped a good deal with the noise & made it easier to have on next to me.
I used a chronodot real-time clock to store the time & date, the unit also has the ability to report temperature. To set the time I use another arduino with a touchshield & xbee Bluetooth module. There is a corresponding xbee inside the clock so you are able to update the time wirelessly. Recently I added background color updating to predefined colors cyan yellow & magenta. The reason for defining the colors is for simplicity & the fact that RGB are already used for the hands of the clock. On the remote there is also an option to switch to a temperature display. This polls the chronodot for the tempature then displays it in 25 degree increments. So for 80 degrees Fahrenheit there would be three full pie slices & a small portion of a fourth to represent 80.