POV Globe

POV Globe is basically a circular array of light emitting diodes, rotating at a very high angular speed to produce a spherical screen. By synchronizing the blinking speed of led’s with angular speed of motor we can generate a very fine 3-D display on spherical screen.

The term persistence of vision refers to a phenomenon of human vision: a light stimulus lingers as an aftereffect on the retina for about 1/10 of a second. When light stimuli are sequenced in rapid succession, they merge into one continuous image. Scientists still argue how much of this phenomenon is shared between the eye and the brain, but the effect is real — in fact it’s the basis for film and television.

In most POV displays, a linear (1-dimensional) array of LED lights rotates around a single point, like a bike wheel. By measuring their rotation rate and controlling their flashes with millisecond precision, we can create the illusion of a 2-dimensional image lingering in thin air.

In our POV Globe, we’re adding a new dimension. We rotate a curved array of LEDs around a rotational axis, like a planet. When the flashing LEDs draw images in the air — say, the continents of the Earth — the result is a 3-dimensional, spherical illusion: a globe! 

This was made by us to present in the exhibition organized by  wayamba university last year….

Here are some photos...

 

Globe was perfectly visible to the naked eye.. these images were blured because of the unmatchingshutter speeds of the camera..  

Me and one of my team mate

Parts used

The main processor was a at mega 328 chip. 40 leds were used as individual pixels. 74hc595 shift registers were used to drive the leds.. high power motor used to rotate the led bar. hall sensor was used to detect the position.

Pcb and the chasis were built by us ..