I've wanted to make a halloween project for a while now. The neighborhood kids always get a kick out of the decorations we put out. When I came across the SonicSurface project I knew I could retask it to create something scary for the local kids.
My current intention is to conceal one 256 transducer array above a dusty surface and remotely trigger (or via simple motion sensor) "Spirit" writing on the surface. I want to make the surface obvious that nothing is concealed within, so the kids can actually touch the dust too... Resetting the dust (baking soda?) would have a bin of baking soda and a servo with compressed air to "redistribute" between groups of kids.
PLEASE COMMENT WITH TIPS OR IDEAS - I WOULD LOVE TO HAVE THE FINAL VERSION WORTHY OF SCARING MY LOCAL NEIGHBORHOOD KIDS (Maybe Adults too?)
Build and Prototyping:
So first I went through the SonicSurface build instructions. Their Instructables.com write up is an excellent read and has many useful details.
Here is one of the completed arrays. I had a couple issues with the driver ICs on the reflow front, but managed to fix them with a hot air gun.