Many halloween decorations don't move, and what's scary about that? Yeah, nothing so I will be showing you how to build your own skull and make the jaw move when a person walks by. I started this project because I was staring at my nonmoving skeleton and got a thought, "Maybe I can replicate this skull and make the jaw move". That's when this whole project began.
*Note* If you liked this idea or instructable, please consider voting for it in the halloween decoration contest!
Thanks for Reading this Instructable!
Step 1: Materials
You will only need a few materials to build the skull.
You will need:
leds (Red works the best)
colored paper (optional)
Step 2: Make the Skull
Download this document and print it, I enlarged mine by 1.5x.
Once printed, cut out the paper according to the key. Make sure all cuts are accurate or the skull won't fit together. Use hot glue to assemble the skull, In the places that are weak add more glue.
Step 3: Assembling the Electronics
Glue a piece of cardboard to the jaw to make it firm. Attach a long piece of cardboard inside the skull. Glue your servo horn to the jaw hinge and glue the servo to the piece of cardboard sticking out. Later, connect jumper wires to the LED terminals and glue it inside the skull eyes. Make a hole in the back of the skull so the wires can go through the hole.
Step 4: Adding Sensors
Make a hole in a cardboard box. Glue the skull to the box and stick the wires through the hole. Finally, add a little glue to the bottom of the ultrasonic sensor and fit it under the skull. Connect wires to the sensor and make a hole right where the jaw is so the sensor wires can go through there.
Step 5: Programing the Arduino
Make two holes in the inside of your box. find two screws and two nuts so you can screw the arduino into place. Then, connect all the components together according to this schematic. Ultrasonic TRIG goes to pin 13 and ECHO goes to pin 12 for any clarrification about sensor wiring. Next, download the code and upload it to your arduino.
*Note* When servo is moving you might need to adjust the servo horn
*Note* You will need to adjust the distance to your specification
Step 6: Decoration
Lastly, glue a bunch of colored paper (I used orange on the front and black on the sides) so that it covers any cardboard. I used orange and black because it's halloween colors. Now all you have to do is give it power and watch as the skull moves it's jaw as someone walks by.
congratulations you are done!