Persistence of vision display tutorial - Persistence of vision: how does animation work? - Explore.



Persistence of Vision (POV) effects let you display arbitrary images with just a few controllable pixels on a fast moving object by changing the pixels' colours fast enough. There's plenty of existing POV projects using a LED strip on a spinning object, like a bike wheel or a spinning CD.

This is yet another implementation of POV on a bike wheel. Adafruit has a similar project , they sell the kits and have it well documented, there's probably a few more implementations. All the ones I've seen used custom LED controller circuits though. This instructable uses just the most obvious, off-the-shelf elements and requires some basic soldering and a lot of zip-ties.

It also allows you to switch the LED effect programmes without getting off your bike, by using short sequences of braking ("gestures") which are detected by the same sensors we use for keeping track of the wheel position. Wifi, bluetooth, etc. control would also be easy but I've not done that.

Here are the materials I used, but you may have similar components at home that are likely compatible and will work just as well.

This should come out at about $100 in total or less than $50 per wheel. You also need a LiPo charger if you don't have one. You'll also need a bike (or at least the wheel).

If you're new to Arduino, you should know that you'll probably need a USB-to-Serial adapter to program the board, unless the Arduino has a USB port already or unless you have a real serial port & cable in your computer. If you don't code, you probably want to reproduce my setup exactly.

Maybe you’ve seen a persistence-of-vision (POV) illusion before: an array of bright LEDs on the spokes of a spinning bicycle wheel that magically paints colorful animations, light effects, and messages in the night. These visual effects are always good for a “Wow!” — but we’ll go them one better and build a 3-dimensional illusion: the POV Globe.

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! Of course, our globe can make other images — like the Death Star from Star Wars, a skull, or the Make: logo — appear magically in the room. It all depends on the perfect timing of the LEDs.

This project has 4 main parts: the electronics, which control at least 24–40 LEDs using an Arduino Nano microcontroller and 74HC595 shift registers; the POV Calculator software that breaks down an image into a bit-pattern that your globe can display; the Arduino sketch that breaks this pattern into segments and sends it to the shift registers; and, finally, the mechanics that rotate the LEDs. It’s a moderately difficult project, but with a little experience on the soldering iron and some woodworking and metalworking skills, it can be accomplished in a weekend.

The microcontroller’s job is to issue a predetermined pattern of binary pixels to the large number of LEDs. This data must be sent synchronously with the ring’s rotation, triggered by a magnetic field sensor (a Hall effect probe). But the Arduino has relatively few output pins, so we resort to a trick: We use simple shift register chips, which collect the serially transmitted data (8 bits per chip) and on command make the data parallel (available all at once) at their output pins. This strategy takes advantage of the Arduino’s high-speed serial (SPI) pins, requires much less programming effort, and greatly simplifies the wiring.

Persistence of Vision (POV) effects let you display arbitrary images with just a few controllable pixels on a fast moving object by changing the pixels' colours fast enough. There's plenty of existing POV projects using a LED strip on a spinning object, like a bike wheel or a spinning CD.

This is yet another implementation of POV on a bike wheel. Adafruit has a similar project , they sell the kits and have it well documented, there's probably a few more implementations. All the ones I've seen used custom LED controller circuits though. This instructable uses just the most obvious, off-the-shelf elements and requires some basic soldering and a lot of zip-ties.

It also allows you to switch the LED effect programmes without getting off your bike, by using short sequences of braking ("gestures") which are detected by the same sensors we use for keeping track of the wheel position. Wifi, bluetooth, etc. control would also be easy but I've not done that.

Here are the materials I used, but you may have similar components at home that are likely compatible and will work just as well.

This should come out at about $100 in total or less than $50 per wheel. You also need a LiPo charger if you don't have one. You'll also need a bike (or at least the wheel).

If you're new to Arduino, you should know that you'll probably need a USB-to-Serial adapter to program the board, unless the Arduino has a USB port already or unless you have a real serial port & cable in your computer. If you don't code, you probably want to reproduce my setup exactly.

Maybe you’ve seen a persistence-of-vision (POV) illusion before: an array of bright LEDs on the spokes of a spinning bicycle wheel that magically paints colorful animations, light effects, and messages in the night. These visual effects are always good for a “Wow!” — but we’ll go them one better and build a 3-dimensional illusion: the POV Globe.

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! Of course, our globe can make other images — like the Death Star from Star Wars, a skull, or the Make: logo — appear magically in the room. It all depends on the perfect timing of the LEDs.

This project has 4 main parts: the electronics, which control at least 24–40 LEDs using an Arduino Nano microcontroller and 74HC595 shift registers; the POV Calculator software that breaks down an image into a bit-pattern that your globe can display; the Arduino sketch that breaks this pattern into segments and sends it to the shift registers; and, finally, the mechanics that rotate the LEDs. It’s a moderately difficult project, but with a little experience on the soldering iron and some woodworking and metalworking skills, it can be accomplished in a weekend.

The microcontroller’s job is to issue a predetermined pattern of binary pixels to the large number of LEDs. This data must be sent synchronously with the ring’s rotation, triggered by a magnetic field sensor (a Hall effect probe). But the Arduino has relatively few output pins, so we resort to a trick: We use simple shift register chips, which collect the serially transmitted data (8 bits per chip) and on command make the data parallel (available all at once) at their output pins. This strategy takes advantage of the Arduino’s high-speed serial (SPI) pins, requires much less programming effort, and greatly simplifies the wiring.

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The Destination Imagination program is a fun, hands-on system of learning that fosters students’ creativity, courage and curiosity through open-ended academic Challenges in the fields of STEM (science, technology, engineering and mathematics), fine arts and service learning. Our participants learn patience, flexibility, persistence, ethics, respect for others and their ideas, and the collaborative problem solving process. Teams may showcase their solutions at a tournament.

-Melissa Dick, Parent & Team Manager THE CREATIVE PROCESS Destination Imagination participants experience these components of the creative process while solving our Challenges.

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Persistence of Vision (POV) effects let you display arbitrary images with just a few controllable pixels on a fast moving object by changing the pixels' colours fast enough. There's plenty of existing POV projects using a LED strip on a spinning object, like a bike wheel or a spinning CD.

This is yet another implementation of POV on a bike wheel. Adafruit has a similar project , they sell the kits and have it well documented, there's probably a few more implementations. All the ones I've seen used custom LED controller circuits though. This instructable uses just the most obvious, off-the-shelf elements and requires some basic soldering and a lot of zip-ties.

It also allows you to switch the LED effect programmes without getting off your bike, by using short sequences of braking ("gestures") which are detected by the same sensors we use for keeping track of the wheel position. Wifi, bluetooth, etc. control would also be easy but I've not done that.

Here are the materials I used, but you may have similar components at home that are likely compatible and will work just as well.

This should come out at about $100 in total or less than $50 per wheel. You also need a LiPo charger if you don't have one. You'll also need a bike (or at least the wheel).

If you're new to Arduino, you should know that you'll probably need a USB-to-Serial adapter to program the board, unless the Arduino has a USB port already or unless you have a real serial port & cable in your computer. If you don't code, you probably want to reproduce my setup exactly.




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