Oct 072009

If you want a slightly different look for your Halloween pumpkin or skull, you can pretty quickly whip something up with a few servos and an Arduino. Here’s a set of Scary Shifty Servo Eyeballs, for instance:

It looks around randomly…what’s over there!… wait, what’s that!

As you can probably tell it’s a pretty simple arrangement (click for bigger):
Scary Shifty Eyeballs

Scary Shifty EyeballsScary Shifty Eyeballs

Building It

It consists of the following components:
- 2 toy eyeballs or ping pong balls painted like eyeballs
- 2 small servos (HXT500 from HobbyKing.com or similar)
- 1 standard servo
- 1 Arduino with tiny breadboard rubber-banded on top
- 2 BlinkMs, one for each eyeball, running a custom light script
- hot glue, popsicle sticks, and bits of wire
- Arduino sketch (ScaryShiftyServoEyeballs.pde)

Hot glue is the best thing ever (and reversible in case of mistakes), so invest the $7.99 in a hot glue gun, get some structural hardware like popsicle sticks, and go nuts. Glue down the smaller servos for the eyes to a base, glue a servo horn underneath the base, then plug that into the larger servo. Get two servo horns for the smaller servos (the servos come with several), glue each eyeball to a servo horn and then you can snap the eyeball+horn onto the smaller servo. If you want the eyeballs to light up, drill or poke a hole in the back for the LED and hot glue the LED into the eyeball.

Once all the construction is done, wire up the servos to Arduino. The control pin of the servo goes to an Arduino digital pin (I used pins 5, 6, & 7). The power and ground pins of the servos go to +5V and Gnd on the Arduino. Then load up the Arduino sketch!

Some neat changes to the sketch would be adding some sensors to make the eyes look you when the sensors are triggered. One easy sensor to add would be a piezo knock sensor. Run the piezo under a rug and someone steps on the rug, the piezo is triggered and you can make the eyes look in that direction.

Servo Primer

If you’re unfamiliar with servos, check out the current issue of MAKE. In MAKE volume 19, I have an article that’s a servo primer with two little fun projects you can build in an afternoon. Go now! Get it! You can get a taste of the servo primer if you like. I think the article came out pretty good.



If you’re unfamiliar with BlinkMs, you might want to check out my BlinkM Hello post. BlinkMs are smart LEDs that can become any color and can play back custom “light scripts”.

 Posted by at 8:18 pm

  9 Responses to “Scary Shifty Servo Eyeballs”

  1. [...] you have 3 servo motors, some scary eyes, a few Popsicle sticks and an Arduino you can also make a some crazy eyes! Just add a white sheet and stick these Servo controlled Eyes under it and you will have the [...]

  2. [...] to the todbot blog for more info, and to download the Arduino [...]

  3. [...] to the todbot blog for more info, and to download the Arduino [...]

  4. [...] to the todbot blog for more info, and to download the Arduino [...]

  5. This reminds me of stories of an old mainframe (or DEC 10?) system console hack. The system had two monitors at the sysadmin table. Someone set it up so in the middle of the nightshift, two eyes would appear on the monitors, look around and then disappear. Way to freak out the (already freaky) sysadmin!!

  6. [...] it would appear to be following someone moving nearby. (I later found that Tod Kruft has a recent project doing something very similar, though it wasn’t linked to [...]

  7. I have been looking for code like this to do this exact same thing. Thanks so much for the information and sketch.
    All the little kiddies will get a kick out of it this Halloween. I will give you full credit also.
    Thanks DUDE!!!

  8. [...] is a recreation of a project that I saw on todbots website. It was called “scary shifty servo eyeballs“. Mine just has a face over it made out of cardboard paper. Its a great way to reuse those [...]

  9. […] love to see someone hack it with a servo to really up the creep factor! Using something like this Arduino controlled rig created by Tod […]

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