Definition –

“Persistence of vision refers to the optical illusion that occurs when visual perception of an object does not cease for some time after the rays of light proceeding from it have ceased to enter the eye. The illusion has also been described as “retinal persistence”, “persistence of impressions”, simply “persistence” and other variations.Wikipedia

So I wanted to make something for my sister on her birthday so I thought it might be cool to make a 5 LEDs POV display printing “HAPPY BIRTHDAY”

It is one of the most well-documented builds on the internet so I am not going to do it again instead I will just share you some details, few cool photos and the code for the project.

I decided to use red LEDs with the current limiting resistors, to control the LEDs I used a small PIC12F683 8-bit microcontroller and used two coin cell batteries to power the whole thing. As this was fairly simple built I didn’t bother to draw a schematic for it but if you refer other builds on the internet it is basically the same.

It’s awesome that PIC12F83 has such a wide voltage range, the only limitation in terms of voltage was the (Forward Voltage of LED + 0.3V). I used microcontroller’s internal RC clock for the build.

Datasheet Snip

Here are few pictures of the final result, later on, I poured in a lot of hot glue to cover the back.

Here I used Long Exposure Camera App to take this shot, I don’t think this camera app really takes long exposure shots but instead uses image processing to give the same effect. Anyway, they turned out very well.

As usual, find the code on my GitHub page and happy building.

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