Category Archives: ball

Follow the Bouncing Ball of Entropy

When [::vtol::] wants to generate random numbers he doesn’t simply type rand() into his Arduino IDE, no, he builds a piece of art. It all starts with a knob, presumably connected to a potentiometer, which sets a frequency. An Arduino UNO takes the reading and generates a tone for an upward-facing speaker. A tiny ball bounces on that speaker where it occasionally collides with a piezoelectric element. The intervals between collisions become our sufficiently random number.

The generated number travels up the Rube Goldberg-esque machine to an LCD mounted at the top where a word, corresponding to our generated number, …read more

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Posted in arduino, Arduino Hacks, Arduino Uno, art, babble, ball, digital, frequency, kinetic, piezo, poetry, poetry robot, pseudo-random, rand, random, random number generator, rube goldberg, speaker, square wave, tone, uno | Leave a comment

Ping Pong Ball-Juggling Robot

There aren’t too many sports named for the sound that is produced during the game. Even though it’s properly referred to as “table tennis” by serious practitioners, ping pong is probably the most obvious. To that end, [Nekojiru] built a ping pong ball juggling robot that used those very acoustics to pinpoint the location of the ball in relation to the robot. Not satisfied with his efforts there, he moved onto a visual solution and built a new juggling rig that uses computer vision instead of sound to keep a ping pong ball aloft.

The main controller is a Raspberry …read more

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Posted in ball, computer vision, juggling, Object, opencv, paddle, ping pong, Raspberry Pi, robots hacks, table tennis, tracking | Leave a comment