The Monster Shooting Range was an interactive Halloween exhibit that I built for one night a year... with multiple monsters that came to life and could only be killed with laser tag guns.

I had been building Halloween installations full of robotic monsters for over a decade, but I had the idea to make the experience more interactive and visceral by hacking a kids laser tag game to make the monsters killable.

I reverse engineered the Wow Wee Light Strike infrared "laser tag" target sensor signal and hooked the sensors up to a BeagleBone microcontroller. This allowed me to detect when the kids shot the monsters so I can deactivate them when shot.
 

I also discovered that Halloween props for sale in retail all had "Try-Me" buttons that acted as toggles; they both turned the monster on and also off. This meant that I could control them with a single line connected to a relay. I also run A/C for lighting, D/C for motors and the whole thing is wired with stranded CAT6 cable which fits perfectly into breadboard or header sockets when tinned.

The system runs in Python on a BeagleBone Black which is an awesome little board that provides a full Linux environment with dozens of available GPIO and is reconfigurable to run in many different modes. For my purposes I need as many GPIO as possible and currently have it configured to provide 64 usable I/O lines.
 

The monsters were set up in my garage in a labyrinth of black plastic sheeting so only one monster was visible at a time. The kids run through with guns in the dark, and each monster comes to life with lights, sounds and movement. The kids have to 'kill' the monster with their IR guns whereupon it stops moving and the next monster comes to life...

I built a very simple mechanism using a single motor, mending brackets and string to animate the inanimate props so that all the monsters move when activated. The whole mechanism including the motor only cost $15 so I was able to animate a lot of monsters...

The first year I had 7 monsters operating, including my giant Halloween Spider and The Mummy, but this expanded to a total of 13 monsters including my gianty robot Marauder!
 

  Click on the thumbnails below for video: