Instructables

The first time I saw a POV (Persistence Of Vision) display was on a show called FAQ on TV. The POV display consisted of an oscillating shaft with 6 LED's mounted on the end of the shaft.

Since then I have always wanted to make one myself, I tried making one about 2 months ago with an oscillating shaft myself but I was not successful as the speed of the shaft was too low for the POV display to work. Now I decided to make the POV display with just a DC Motor instead of an oscillating shaft as they are much cheaper and easily available compared to the shafts.

In this instructable I will show you how to make the POV Display yourself!

This is a very simple project both on hardware and software (coding) areas. It costed me only about 5$ to make it from start to finish!

So lets get started!

Here is a video of it in action!

Note: The brightening and dimming of the LEDs in the video is due to my crappy camera, in reality its consistent and quite bright.

Step 1: Persistence Of Vision and how it works

POV stands for Persistence Of VIsion.

Persistence Of Vision is the phenomenon of the eye by which an image seen by our eye persists for about 0.04s during which any other images that we see are merged together with this image.

This phenomenon is used in the POV Display as we turn the LEDs on and off in such a way that the different images overlap each other forming letters.

For example:

The formation of the letter E with 5 LEDs;

1 2 3 <- Time

1 1 1 <- Bulb 1

1 0 0 <- Bulb 2

1 1 1 <- Bulb 3

1 0 0 <- Bulb 4

1 1 1 <- Bulb 5

Each column represents the 5 LEDs we used to make the display. Each element in the row represents the state of the LED at that given time.

So at t = 1 Bulb 1,2,3,4,5 are all on

at t=2,3 Bulb 1,3,5 are on

This way we can visually see the letter E formed by the LEDs but the time interval would be very small in milliseconds and not as given in the example.

Due to the short time intervals and the ability of the LEDs to turn on and off very quickly we can see the letter E as all the 3 images merge. As the motor is spinning, as time passes the LEDs move from one position to the next so all these images are merged together.

For more information on how this works have a look at these links:

Note: You can see in the above images how the 3 different pictures merge to form the letter E

Here is an animated gif that shows the formation of the letter E :http://www.instructables.com/files/orig/FIZ/ZDS5/HW4OQXU8/FIZZDS5HW4OQXU8.gif

 
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nodcah4 months ago

Awesome Instructable! Also, aren't ATtinys just awesome?!? :-)

vishalapr (author)  nodcah4 months ago

ATtinys are the best mainly because they are cheap and they use the arduino code itself!

ATMega8 are cheap too, you can get them for about 60-80c each, they accept "native" Arduino code at 16MHz and can be programmed on a simple breadboard (or taken from a 1st-generation Arduino)

kidd_king 4 months ago
wonder if you can make a clock out of it

You could, but you have to synchronise perfectly the motor with the display, so you display the bar in an "RISING" interrupt triggered by an infrared sensor pointing to a white wheel with at least 60 "stokes" drawn on it (1 per sector-pixel). ATMega8 seems a minimum, there...

vishalapr (author)  kidd_king 4 months ago

Yea you can but Im not sure about the coding for it, will spend some more time learning and then Ill try make one! :D

victordoes7 days ago

Very useful! Love that you explained some code in the end.

sunilksree made it!12 days ago

Hi vishalapr,

Thank you for this amazing instructable. Inspired from you, I made a RGB POV :)

I have also made aan instructable for it too.

http://www.instructables.com/id/RGB-POV-Display/

F3IWJ1LI11YVLQR.jpeg
colecuc1 month ago

When I click uplode,

avrdude stk500_getsync not in sync resp 0x00

this pops up, any ideas to help? its fully assembled and all the connections are correct. All of the software was also downloaded successfully.

deba1682 months ago

Congratulation :)

vishalapr (author)  deba1682 months ago

Thank you! :D

wkarraker made it!3 months ago

Had enough parts to knock one together. Need a faster motor as the digits are stretched on this one.

Unknown-2.jpegUnknown-3.jpeg
vishalapr (author)  wkarraker3 months ago

It looks great! Yea I had to adjust the speed of my motor to get them just right.

Mic1004 months ago

Thanks is very interressing instructable

vishalapr (author)  Mic1004 months ago

Welcome!

mormo made it!4 months ago

HI, thanks for idea. I made this project on arduino pro mini.

http://techfreak.pl/weekendowy-projekt-pov-arduino...

techfreakpl_simple_pov_arduino_pro_mini9.jpgtechfreakpl_simple_pov_arduino_pro_mini6.jpg
vishalapr (author)  mormo4 months ago

That looks awesome! Great job!

ahmedebeed555 made it!4 months ago
POV.jpgpov2.jpg

Thank you for sharing. Great instructable.

vishalapr (author)  ahmedebeed5554 months ago

Wow that looks very nice and compact! Glad you liked the ible!

Thanks for the pics!!

dwebb54 months ago

Looks like a great way to make my own one of these. http://www.xoxide.com/cooljag-pro-led-flash-120mmf...

Same circuitry can be put in many size fans.

vishalapr (author)  dwebb54 months ago

Thanks! Yea you can use it with fans instead of attaching a motor seperately.

bergerab4 months ago

Too cool! I love seeing what projects people can come up with using attinys. This is one of my favorites!

vishalapr (author)  bergerab4 months ago

Thanks! Glad you liked it!

andrea biffi4 months ago

I merged your three frames in an animated gif :)

animE5.gif
vishalapr (author)  andrea biffi4 months ago

Is the above image a gif? Im not sure how to open it though, I would really like to include a gif in step 2, Thanks!

yup here it's the direct link http://www.instructables.com/files/orig/FIZ/ZDS5/H...

you can reach it clicking on the image

thanks for the gif it made the whole thing simple to understand

vishalapr (author)  andrea biffi4 months ago

Thats awesome, thanks!

craftclarity4 months ago

SUPER COOL!!!! It'd be neat to put this on a pair of bicycle handlebars....so that you could see it from the front.

Adafruit has a POV kit you can put on your spokes.

5-01.jpg
vishalapr (author)  GitarGr84 months ago

Yea this looks amazing when you are riding it!

+1

I can see sending a message like "Hi, just a friendly bicyclist!"
vishalapr (author)  craftclarity4 months ago

Thanks! Yea that would look pretty awesome!