transparent UV color sensing and sorting job Project

Hello everyone,

I am planning to do a color sorting task using an arduino. so I have balls with 3 different colors (Red, Green, Blue) in a
pile and I want to use arduino to sort them into 3 different pile (one pile for each specific color).
It is very similar to this project: Sorting Machine - Skittles and M&M's - YouTube
But a one big thing that is different in my project is that I will be painting each ball with “Transparent Blacklight UV Paint”.
http://www.ebay.com/itm/Transparent-UV-Paint-Blacklight-UV-Reactive-Intense-Glow-/280903848172?ssPageName=ADME:X:AAQ:US:1123
These paints are transparent in normal lighting conditions but when you expose them into purple UV light they glow in a specefic color.
I will be painting white ping pong balls using these paints and put them in a pile. I know that I have to somehow direct these balls
into a dark container and shine UV light on them and observe the color change by using a camera or some sort of color detection sensor that is
connected to an arduino. I was just wondering if the typical color detection sensors will do the job in this circumstances?
since they are exposed to purple uv light? is the dark environment and the uv light going to interfere with the sensor reading?

Also I am a newbie with arduino, how can I get started with this project? which sensor should I go with? is there any sample
arudino programs available? I have seen people doing stuff like this on youtube but I couldnt find a good tutorial explaining the process.
Any help, and guidance would be hugely appreciated.

thanks

The paint turns UV into visible coloured light. Use different (visible light) coloured filters to measure the coloured light emitted from the balls.

Also, if you are worried about the UV light affecting your color sensors, you could include a UV filter to prevent it from reaching the visible light sensors.

jrdoner: Also, if you are worried about the UV light affecting your color sensors, you could include a UV filter to prevent it from reaching the visible light sensors.

I was thinking the same, but good quality (photographic) filters probably won't need that.

jrdoner: Also, if you are worried about the UV light affecting your color sensors, you could include a UV filter to prevent it from reaching the visible light sensors.

Thanks for suggestion, however I do have one question. If I use IR filter, would it black the purple light that comes out of uv leds? because I dont want the purple light interfere with color detection. And what do you think of adafruits color sensor? it comes with the IR filter embeded. https://www.adafruit.com/products/1334

JJoll: Thanks for suggestion, however I do have one question. If I use IR filter, would it black the purple light that comes out of uv leds? because I dont want the purple light interfere with color detection. And what do you think of adafruits color sensor? it comes with the IR filter embeded. https://www.adafruit.com/products/1334

The IR filter shouldn't block the UV or violet light. IR is on the other side of the spectrum.

I think you'll want a way of substituting your UV LED for the white LED on the color sensor board.

If you're using a UV light source, you shouldn't need a IR filter at all. I doubt the paints fluoresce in IR.

I agree with others suggesting you may need a UV filter.

DuaneDegn: The IR filter shouldn't block the UV or violet light. IR is on the other side of the spectrum.

I think you'll want a way of substituting your UV LED for the white LED on the color sensor board.

If you're using a UV light source, you shouldn't need a IR filter at all. I doubt the paints fluoresce in IR.

I agree with others suggesting you may need a UV filter.

Sorry I got confused IR with UV. You are right, I would need a UV filter, since I need a UV LED to light up the paints. So if I use RGB sensor and put a UV filter in front of it, i will be able to filter out the UV light being detected by my sensor. But what about the purple light that coming out of a UV LED? All the UV light sources (black lights) are around 400nm and have some sort of purple colored light coming out of them, and my dilemma is that I dont think uv filter will block the visible purple light and those purple lights will interfere with the color sensing. Am I right? and what can I do about it?

JJoll:
those purple lights will interfere with the color sensing. Am I right? and what can I do about it?

Hopefully, the paint won’t reflect the violet light. If the violet light is reflected, then you’ll need to compensate with software. The violet light will likely affect the reading from the blue sensitive element of the sensor. If this extra blue component is consistent, you should be able to subtract its effect.

One of the things I hope to understand someday is how the brain sees violet (the single color) as opposed to purple (red and blue mixed).