Now we need some software so our Arduino knows what to do with the monster we just attached to it! Here is the sketch I wrote that reads the rotation...
How to build your own adruino based electrostatic field mill. I'm going to show you how to build this amazing device that allows you to monitor the amount of electrostatic potential exists around you. Youll be able to watch the electrostatic fields that follow under clouds, occur when you move and walk or even wave your arms! We're going to build this from parts that almost any body has around the house.
To build your field mill you'll need the following:
An adruino (any model should work)
An old processor or case fan from an old computer (it needs to run and be the kind with 3 wires)
A couple of the clear CDs that come on the tops and bottoms of cr-r spindle packages
One cd any kind
A cd-r spindle package
A glue gun
A dead hard drive
Step 2: Building The Shutters
A field mill works exposing a plate to the electrostatic field and then measuring it. This is done by a machanical shutter that rotates in front of the measuring electrode. For our shutters we're going to use a couple of clear cd spacers and aluminum foil. First we cover one side of a clear cd spacer with foil. We repeat the process with a second clear spacer. Next we use a ruler to divide each cd's foil into quarters, We then remove the foil on each diagonal quarter. Repeat this process with the second disk
Step 3: Installing The Top Shutter
To create the shutter system we first mount one shutter to the inside top of the cd package case. The second shutter will rotate below the top shutter thus creating a metal shieldl that will alternately open and close as the second disk rotates below it. Glue the Top disk to the inside top of the CD-r stack case.