In the future, all the chickens are dead. The Robot Masters felt bad about it, and decided to make it up to us humans by creating a robotic replacement. At least, that's what they said. When pondering the question, "What come first, the chicken or the egg?" their answer was calculated in approximately 2538 clock cycles: The Egg, of course!

This is the result of their work. Or rather, an accurate and authentic replica of the very first robotic egg created by the Robot Masters. Why not post instructions on how to build the real thing? Well, there is a very good reason. When the robotic egg hatches, a robot chicken emerges. Robot chickens are as deadly as rabies-infected grizzly bears* on speed. You see, as usual, the Robot Masters lied to us. The robot chicken was just another effort to wipe us off the planet. You's think they could put all that creative energy to work on something useful, but no. Robot freakin' chickens. *sigh*

Oh! And the worst part? If you do manage to catch and kill a robot chicken, you can't even eat the darned thing! Once you pluck the titanium alloy feathers and remove the fuel cell, the resulting carcass is completely inedible. Worst.pot pies.ever.

So here is an Instructable on how to create the relatively safe (and in a cold robotic way) attractive looking egg replica. It glows pretty colours and responds to sound, just like a real egg!

*grizzly bears are also extinct in the future.

Step 1: Parts and tools

OK, so the intro was a little over the top.

I'm not a big fan of bling, but I adore shiny lights. This instructable will tell you how to build an egg-shaped sound-reactive mood light thingy, with all the glitz and glamour of a real Faberge egg. It also has plenty of tiny fiddly painstaking work, also like a real Faberge egg.

What does it do? Quite simply, it's a 48-LED chaser circuit attached to a microphone. When it hears a loud noise (like a clap), a pulse is sent through the chaser circuit. All the while, changing colours illuminate the egg from the inside. This project requires absolutely no programming, but you will need elite ninja soldering skills. The Electric Ovaloid is made up of two basic circuits:

The LED Chaser

Take a look at the schematic for this one. It looks ridiculously easy, and it is! It's simply six inverters strung together in a chain, with an LED at each step. The trick is the resistor and capacitor at each stage. When the leading inverter changes state (high to low, low to high), it passes that along to the next inverter. However, that state is delayed by the need to charge up or discharge the capacitor. The charge time is determined by the RC time constant of the resistor (1.8 megohms) and the capacitor (0.1 uF) - about 0.18 seconds. If the initial state applied to that first inverter stays constant long enough, then the entire chain of LEDs will eventually turn all high or all low. However, by sending a pulse through the chain, we can cause a "wave" equivalent to the length of that pulse to travel through the chain of LEDs!

Note that the Electric Ovaloid uses eight groups of six inverters (each stage uses six inverters in a single 14-pin package) -- but yours can be of any length. Theoretically the chain could be hundreds of inverters long!

The Sound Pulser.

Do you remember The Clapper? That's basically what this is! When the microphone picks up a loud enough sound, it's amplified by the 741 op amp. It's then sent to the 555 timer which is configured as a "one-shot" timer. The inverter at the end formats the pulse for the chaser circuit. The sound, no matter how brief, is stretched out by the timer to a certain minimum value. In this case, it's the time needed to illuminate at least two LEDs in the chaser circuit. The number of illuminated LEDs (the period of the wave) is determined by the RC time constant of R8 and C4. The sound pulser schematic is a modified version of the one I found here.

Want to make yours faster or slower? Just remember that the "speed" the wave travels through the LED chain is determined by the RC time constant - reduce the value of the resistor or the capacitor to increase the speed. The minimum number of illuminated LEDs (the period of the wave) is determined by the RC time constant of the Pulser circuit. Easy enough? Let's get building!
are you willing to sell that??????
It is currently packed away in a box somewhere. You'd really want to buy it? I expect you would tire of it within minutes.
If I'm reading this right the speed of the chaser circuit is dictated by the resistance and capacitance in the circuit? So to change the Pace of the Chase you'd need to change ALL the resistors and ALL the capacitors?<br><br>Ok it may not be the most &quot;efficient&quot; circuit of it's type, but it's a very elegant solution and it actually looks good too. I'm not sure I wouldn't want it outside for all to see the beauty of the components... <br><br>Nice work.
Can you send me the picture of the schematics of the sound switch plz... pm me
To view the schematics, download Cadsoft Eagle from www.cadsoft.de. Let me know if you can't do that, and I can send a picture of them.
whered you get the egg
I got the egg on Freecycle. The person I got it from said it was the packaging for an Easter chocolate assortment or something.
i thought the chicken came first....
Thank you for your nice comments. Carole B.
Nice work! Congrats on being a finalist!
All those late nights are beginning to feel worthwhile. :)
Congratulations on being a Finalist. I "studied" your design the other night and read your Instructables. It is a fascinating egg; I sent the link to my niece, because I was sure she would be fascinated with it too My Best Wishes to you. Carole B.
Thanks! When you break it down the circuit is pretty basic. I only wish I'd had more time to make a longer chain!
Wow.... That is so awesome! 5 stars!
Thanks! :) It looks even better in real life (as most things do); it was difficult to capture the subtleties of the light patterns on video.
It kind of reminds me of a Cylon.
I'm sure there's a relation somewhere. Third cousin twice removed or something. ;)
That is a sweet egg.
That's really cool! Better than LSD!
Awesome, lots of pics and wonderfully documented. I wonder what Seth Green would think......
I'd like to think that he'd agree with me. ;)

About This Instructable


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Bio: By day, Jeff is the Jack of All Robots at Clearpath Robotics. By night, a mad scientist / hacker / artist / industrial designer wannabe!
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