This is an animatronic coffin for a client as a Halloween decoration. Here you can see the basic case and the internal pneumatic piston that opens and closes the door.

This is the brains of the unit, hidden in a recessed area in the back of the coffin. It is controlled by an Arduino R3 microcontroller and triggered by a passive infrared motion sensor. When the infrared sensor picks up motion, it sends a signal to the Arduino which trips a solenoid that allows air to flow into one end of the piston, opening the door. After a few moments the solenoid trips back to it’s original position and air is pushed into the piston from the opposing end, closing the door.

Here my daughters test it out for me. The sensor, hidden in the small black box on a post just above the pumpkin, picks up motion from around 20-25’ away. This was a fun project that allowed me to test my hand at basic programming and robotics which is something I’ve been wanting try for a while. Hopefully I’ll be able to introduce animatronic features into some of my other projects in the future.