POV Globe

Inspiration

Persistence of vision has always interested me. I've made simple POV projects in the past, but never undertaken a project of this type that is so entailed

How it works

On board there sits a ATMega328p running the Arduino boot loader, along with an NRF24L01+ 2.4Ghz radio commonly found in TurningPoint 'clickers'. The communication scheme the clickers use is as follows: 3 byte address, 127 channel address space allocated with 1Mhz bandwidths, 4 byte data packets consisting of the 3 byte sending address and one ASCII character representative of the button pressed. The clicker is used as a simple way to vary timing and illumination setting of the LEDs on the globe. Each LED on the strip is an WS2812, an RGB LED with an integrated 3 channel 8 bit PWM controller with a daisy-chainable 1 wire interface. The clock speed is around 5Khz allowing for very fluid refresh rates. Patterns and modular arithmetic are used, along with timing tuning from the clicker, to generate mesmerizing patterns on the globe.

Challenges I ran into

SPI communication with the RF chip proved stubborn

Accomplishments that I'm proud of

Building the physical structure for the globe simply out of thin steel rods and an aluminum shaft. Also how it remains well balanced given the on-board breadboard and battery.

What I learned

Sleep helps everything

What's next for POV Globe

Equip the globe with either a gyroscope or magnet/hall effect sensor combination to actively measure rotational velocity so that text, image and more advanced effects can be calculated and engineered.

Built With

• adafruit-neopixel-library-for-simple-dallas-one-wire-communication-to-the-led-strip
• maniacbug's-rf24-library-adapted-for-the-protocol-that-turningpoint-clickers-use