Sometimes you have an idea, and despite it not being the “right” time of year you put a creepy skull whose eyes tell the time and whose jaw clacks on the hour into a nice wooden box for your wife as a Christmas present. At least, if you’re reddit user [flyingalbatross1], you do!

The eyes are rotated using 360 degree servos, which makes rotating the eyes based on the time pretty easy. The servos are connected to rods that are epoxied to the spheres used as eyes. Some water slide iris decals are put on the eyes offset from center in order to point in the direction of the minutes/hours. An arduino with a real time clock module keeps track of the time and powers the servos.

Check out the video after the break:

The jaw opens and closes on the hours – springs are screwed to the inside of the jaw to the outside of the skull behind the bones that surround the eyes; they’re hidden when the skull is in its box. A third servo is used as a winch to pull the jaw open from the inside of the bottom of the chin. When it releases, the springs close the mouth and the clack of the teeth replaces an hourly chime.

A bit late (or early) for Halloween, but it’s a really fun project. [Flyingalbatross1] has made the arduino code available, as well as showing plenty of images of how the parts are put together. Take a look at this this atomic clock-in-a-skull, or you make your own talking skull for Halloween!

via Reddit

Maybe it’s too late to present an Halloween project with a lot of function, so we decide to develope a simple application to show how controll a mandible of a skull.

In this project the skull speaks and moves the mandible according to the sound level.
An Arduino analyzes the level sound of a audio source and drives a servo motor connected to the mandible.
All very simple.

The video show how it works.

The sketch:

/* Skull
 created 2011
 by Boris Landoni

 This example code is in the public domain.

http://www.open-electronics.org

http://www.futurashop.it

*/

#include <Servo.h> 

Servo myservo;  // create servo object to control a servo 

int potpin = 0;  // analog pin used to connect the potentiometer
int val;    // variable to read the value from the analog pin 

void setup()
{
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
} 

void loop()
{
  val = (analogRead(potpin)*3);            // reads the value of the potentiometer
  val = map(val, 0, 1023, 50, 0);     // scale it to use it with the servo
  myservo.write(val);                  // sets the servo position according to the scaled value
  delay(15);                           // waits for the servo to get there
}

The schemtaics shows how we connect the servo to Arduino.

     Download the Fritzing file

Inside the skull we use an old PCB to fix the servo (you can use what you want).

This project wants to be a start point for yours ideas….
Have a good work