This Remote Control Easter Egg has 16,581,375 colors.

This Easter egg has 16,581,375 colors.  The color can be changed using any button on any TV, DVD, or VCR remote.  It fills me with delight.

This project uses an RGB LED to produce colors inside a white egg.  The brain of the random selection is an ATMEL Attiny85 microcontroller programmed with an Arduino board.  The part that communicates with the remote controls is a phototransistor sensitive to the wavelength of light and modulation (carrier frequency) of the remote.  

Step 1: Getting what you will need:

1 Attiny85 (or 45) microcontroller (digikey #ATTINY85V-20PU-ND )
1 common anode RGB LED (I got mine from adafruit.com (#159))
3  220 ohm 1/4 watt resistors
1  Infrared (IR) phototransistor (you can order one from adafruit.com (#157) or salvage one.)
3 or 4 1.4 volt batteries  (I got these at the drugstore (for hearing aids))

The IR phototransisitor that I used in this project came from the front panel of a lifeless VCR.  If you are ordering other parts, it is cheap to buy a new one ($2?), but I actually do get a kick out of digging as many parts as I can out of old machines.

The resistors only serve to limit current to the LED, so anything from 180 to 560 would really be OK, just use 3 of the same value.

If the RGB LEDs you find are common cathode, connect the common pin to ground, obviously, but I think the code will still work, just producing the chromatic compliment of whatever you would get from a common anode part.  I think.  

For this circuit, I stacked up 4 little batteries and got about 5.4 volts.  In the past, I have run projects using the Attiny85 and RGB LEDs with a 3 volt coin cell (CR2032 type), but the IR transistor in this project seems to really want 5 volts to run properly.

Comments

[waterlubber]

very nice, wish i had a blue led (i have red & green)

[Snipe8200]

How did you get 16 and a half million colours!?? :P

[SpagoPizza]

This seems odd to me as well . And also , how did you count it all ?

[kendrickgoss]

Each of the LED colors can be powered by the microcontroller from "0" no power, up to 255 "full power." Mixing the 3 colors at different values results in all the colors of the spectrum. SO: 255 x 255 x 255 = 16,581,375 color combinations. Practically speaking, we can not possibly tell a difference between combination 255-116-83 and 255-116-82, for instance, so in a sense this is an exaggeration. When writing this code, I actually wondered if the apparent variety would actually be increased if I had the colors changed by 10s, that is 25 x 25 x 25 = 15,625 colors. In this case the differences between the similar colors with be greater. But I have not tried this.

[bgepp1]

so how does the TV controller control? It would be great to see a video of this egg in action

[kendrickgoss]

The TV controller sends out infrared light in little pulses at a rate of 38,000 times a second, hence, 38kHz. To control a TV (or DVD player, or other) to do a specific thing, it sends these little pulses out in timed packets - it's not Morse code, but similar idea. This circuit (specifically the IR sensor part) watches for 38kHz, but there is no decoding of the information going on. Think of a circuit that is noise activated, rather than voice recognition. A video is a great idea! I will try figure out how to do that. Thanks for the comment!
P.S. Your cell phone camera can see parts of the light spectrum that you can not. One cool thing to do: turn on your cell phone camera and point the remote at the lens and press any button. You can see the flashing packets! (This is also a good way to judge the battery strength of your remote!)

[bgepp1]

whoa that's cool, I just tried the cell phone trick and it worked! Very cool stuff. thanx

[Awesome-aniac]

I have just started using Attinys and this would be a great project to make. Once I learn C (I only know a different language) I could build off of the code that you have posted. Good job.

[kendrickgoss]

Thanks! I really learned most of what I know by buying a book and just plowing into a project I had in mind. I am sure that someone which greater expertise in Arduino or Processing (or electrical engineers looking at the schematic!) could find many ways to improve it. I look forward to any riffs you have on this one!

[Krayzi99]

I'm sure this would work in a plastic easter egg, too. Only problem is mine are already covered

[kendrickgoss]

I have seen LEDs in plastic and real eggs and they seem to work. The advantage with the white egg is that it is white. I tried this in a brown egg, but it simply blocked out rather than diffused the light. Pick a neutral color I guess?

[Krayzi99]

Also, just noticed i said "covered" instead of "colored". sry for doubly post

[Krayzi99]

Yeah, maybe. I only have bright red and dark green eggs, so it will be hard...