This easy tutorial can be quickly assembled in 45 minutes. This is also easily adaptable. For example, add a set of "following eyes" to a pumpkin to create a creepy jack-o-lantern, or use a glow stick as a quick-to-setup light source.
Step 1: Materials
Pingpong ball (1 or 2)
X-Acto knife or Scissors
NeoPixel Strip (length of 10 LEDs)
3 x AAA Battery Pack
AAA x 3
Alligator Clip Test Leads x 3
USB Cable - A / MiniB
Black Sharpie Marker
Multimeter for Debugging Gemma and LED strip (in case you need to debug the electronics)
Step 2: Splitting the Pingpong Ball
If you do not have an X-Acto knife or similar tool, you can use scissors. In my personal experience, I require two pingpong balls doing it this way. First, carefully poke a hole with the tip of the scissors, then start cutting finding your way to the seam. Continue cutting along the seam. Repeat with the second pingpong ball.
Step 3: Cutting Out the Eyes
Place the two pingpong ball halves on the back side of the box and trace them with a pencil, creating two circles.
In one of the circles, trace out the contours of your eye. Be sure to leave padding between your eye shape and the circle outline. Use your artistic ability to create something either menacing or a bit on the goofy.
Use the X-Acto knife to carefully cutout the outline of your drawn eye shape.
Flip the the cutout horizontally and place it in the other circle. Trace with your pencil. Cut again using the X-Acto knife.