Persistence of vision is a really cool visual phenomena where a pulsing light source moved over a distance can be used to give the illusion of a persistent image hovering in space. As a kid, I had a toy frisbee with a string of LEDs on it that let you spell out messages that you could read while the disc was spinning. Brilliant application.
Fast forward about 15 years and I needed a clever way to show short text status messages in an embedded system for a project I was working on in ECE 4534. What could be a better solution than Krazy gluing a MiniPOV3 kit to a box fan and sending data to the unit over infrared? In retrospect maybe an LCD screen would have been easier.
The tool I wrote lets you draw the desired image and generates C code that can be used with the MiniPOV3 kit to flash the LEDs with appropriate timing to draw out the image when the unit is in motion. You can use the tool here: POV