Picture of LASER Maze 2012 - Halloween Haunted House
A new version of the LASER Maze for 2012!
(find the old version here: LASER Maze 2011)

See the PHOTOs on step 7!
See the VIDEOs on step 8!

What is it?
The LASER Maze 2012 is a movie-style laser "security system" that is set up in the front half of my garage haunted house. Trick-or-treaters must dodge a web of green laser beams to avoid setting off the lights and sirens that are protecting the candy in the back of the garage.

How does it work?
The LASER Maze uses an Arduino microcontroller and a PC running Processing. The Arduino is wired to 4 light sensors. Green handheld laser pointers are fixed to the garage wall and pointed at the light sensors on the opposite wall. When the laser beam is broken, the Arduino activates a flashing red light and sends a signal to the PC to play an alarm sound. The Arduino is also constantly sending light level readings to the PC, which are displayed on screen as bar graphs. This helps the LASER Maze operator monitor and calibrate the sensors. 

How is the LASER Maze 2012 different from last years version?
The old 2011 version of the LASER Maze was designed as a game where players watch an intro video clip, hit a start button, navigate the maze, then hit the stop button to see their total time and score. The game aspect didn't work very well for a Halloween setting, because there was a constant flow of trick-or-treaters running through the maze. Also, the old 2011 version did not include any way to monitor your light sensors, which made troubleshooting difficult if things weren't working as expected.

The LASER Maze 2012 fixes some of the problems I experienced with the old version. It is now a continuously running system with no start or stop button. Time and number of lasers broken are no longer tracked, and there is no video clip (which makes setting it up easier!). Since there is no intro video, the PC monitor is now used to display data from the light sensors, which is extremely helpful for calibrating and troubleshooting the system.

One last note on safety before we get started. Please BE SMART if you build your own LASER Maze. Use low power lasers and keep them low to the ground to avoid eye injuries. Check out the Wikipedia entry on laser safety
brandon832 years ago
well done! great improvements.
bkhurt (author)  brandon832 years ago

hi- -any chance you'd like a job being flown to Florida a few months from now to set up a permanent laser maze in one bedroom of a project we're doing? Serious offer-- My email address is andrew@theeverafterestate.com

skakad17 months ago

i got this error...

how to clear this error?

my ardiuno port is com 4.still not run

skakad17 months ago


  • myPort = new Serial(this, Serial.list()[1], 9600);
mhoudek1 year ago
Can I run this on a mac?
Jeff Haas1 year ago
Here's a few ways to make this easier and save a few bucks...

You don't need to do something as elaborate as having a servo turn on a powerstrip. There are plenty of relay boards available now that will easily work with an Arduino. Google "Arduino relay", there's a picture of an 8-relay model in ihart's post. These connect to the Arduino's 5V, GND and a data pin; drive the pin high to turn on the relay. The relay then controls the power for the flashing light. A single relay board is only a few dollars.

You can find inexpensive police lights at party stores that run on AA batteries. Drill a hole in the side and solder a couple of wires to the contacts of the on/off switch, then connect those wires to the relay.

If you want to use a rotating light that runs on line voltage, cut one of the wires in an old extension cord and run that into the relay - again, see the picture in ihart's post. Then plug the light into the cord and plug the cord into the wall. And cover up the connections (that's the black electrical tape in ihart's picture).
ihart2 years ago
This is a small Instructable to show how I built the laser mount and CDS photo resistor mount for our laser maze.

ihart2 years ago
Here are two pics of our Laser Maze setup for Halloween 2012. It was awesome with about 40 kids coming through our maze! I also added a pic of our Process display and the boards I used. One of them is a relay board ($16) for switching the AC on/off to the flashing red light. Thanks again for this great Instructable!
DeusRex2 years ago
I set this up for last night, and it was an absolute hit. The kids and parents loved it. Here are some changes I made:

My lasers didn't arrive from China in time, so I had one green laser to work with and ended up bouncing it around on 6 plate glass mirrors. The beam got a little fuzzy at the end, but it was still visible. (I wish I had noticed your suggestion to use hard disk platters beforehand)

Instead of TP tubes and vellum, I used a standard Red Solo cup for my CDS sensor. I put the sensor in facing the back of the cup, and when the laser hit the cup, the whole thing lit up bright green. I had zero sensitivity issues no matter the fog or lighting, and I had a very large target to hit.

My favorite change is how I activated the Red Beacon light. I tried your servo-glued-to-power-strip technique and couldn't get it to work. I ended up purchasing a $8 "Dusk/Dawn" light bulb socket and stuffed an LED in front of the sensor, and screwed in an outlet adapter into the the sensor. The arduino only had to switch an LED to activate the beacon and worked flawlessly.

Additionally, I built a "Laser-protected Candy Safe". I lined the first 3 inches of a medium box with mirrors, and zig-zagged a laser, creating a laser barrier. When the kids reached for the candy and broke the beam, a servo closed a lid on the candy. The kids loved it, but it did make the candy a little too difficult to get.

Thanks for the Instructable!
bkhurt (author)  DeusRex2 years ago
Sounds great - did you get any pics or video?

I bet the solo cups work even better than the tubes I made. I like your
AC power hack too. Next time, I might try wiring the Arduino to the remote of a remote controlled power outlet like these.

Thanks for posting - I'm glad to see other people building their own laser mazes!
hi bkhurt
can i be able to use arduino uno for this project, do need to do any sort of change in the programming or any where else, please let me know
bkhurt (author)  sujayjoardar2 years ago
I have never used an Uno, but I would guess that it will work fine. The Arduino code is pretty straight forward, and I don't believe there is anything specific to the Duemilanove.
ihart2 years ago
This is just awesome! I implemented this Instructable to use tomorrow night which is Halloween. I will follow up with some pics later.

I have one small issue that I'm not sure I understand. When I get the first alarm, I get a constant tick noise sound pulse coming from the Processing SW exactly every 2 seconds. Everything still works including the rotating alarm sounds but the tick noise audio stays there. I don't see anything obvious in the code. Any ideas?
bkhurt (author)  ihart2 years ago
Nice job getting it set up in time for Halloween. I haven't noticed the ticking noise on mine, and I can't figure out what it might be. I will listen to mine closer when I get the stereo hooked up.

One change I plan on making before tomorrow night is to increase the "sensitivity" value on the Arduino program. The default value is too low once I got to testing with the fog machines running.
ihart bkhurt2 years ago
Re: the tick noise, I did not hear it on my windows 7 desktop. When I ported it to an older HP winxp laptop, it started. It's actually not that bad a sound. It kind of adds some creepiness.

I also had to modify the sensitivity when I ported it to the laptop. I used 150.