A Giant Scrolling Text Display Made of Black and White Marbles
A giant rotating ring displays scrolling text using black and white marbles as pixels. Radial channels around the ring each hold seven marbles to form a vertical column of the display. Once a column has passed, its marbles roll back down to be reused for the next characters.
Creator Ivan Miranda built the mechanism with just three motors to rotate the ring, select the marble colors and feed the marbles into the channels.
Details: Hackster.io ↗ · Open video or post ↗

To make text scroll, the pixels themselves have to roll around a giant wheel. The display is doing almost as much moving as the message.