Laser MazeSensors and lasers can create a fun maze or an unbreakable security system!
Overview
We built a simple detection system in beginner projects, where blocking a light source would set off an alarm. This project has the same idea, but it uses lasers for added sensitivity. You can also set up multiple lasers to make a game for you and your friends. As always, the sky's the limit!
Laser System Components
- Lasers: Unlike other light sources, lasers emit light in a strongly focused beam that barely spreads. This focus, also known as collimation, allows laser pointers to show up on an opposite wall as a single dot rather than a broad bright spot. Because lasers are so strong, they can cause eye damage, so make sure you never look directly into one! When you buy laser pointers, check the strength to ensure you won't accidentally hurt yourself while building.
- Light sensor: You can use a simple photoresistor for your sensor. Mount the laser so it points directly at the photoresistor. If the path of the laser is broken, the resistance will increase, and your Arduino will pick up the difference. Photoresistors are also called LDRs (light-dependent resistor) or CdS cells (cadmium sulfide, the photoresistant material).
- Alarm: You'll need some way to check whether the path of your laser has been broken. You can use a speaker for a harsh buzz, a flashing light, or both. If you're going for a stealth system, you can also simply log the information and confront the perpetrator later.
Project Ideas
Image by Jonathan Robson
Single Laser Box:
This instructable sets up a single laser and sensor to demonstrate the basic principles of a laser tripwire system. Here, a buzzer goes off to alert the user that the laser line is interrupted, but you can add a flashing light for a greater shock.
Image by Adum24
Hidden Laser Tripwire:
Like the last project, this one contains only a single laser, but it's housed inside an Altoids tin for added invisibility. The tutorial is a little vague on the specific circuitry, but it's about the same as the previous one.
Timed Laser Maze:
The maze here, originally created for a Halloween haunted house, is built for one player at a time. It will keep track of time and number of lasers broken. This works well when you're trying to compete with friends.
Image by bkhurt
Continuous Laser Maze:
This maze was also built for Halloween, but unlike the last one, it doesn't time the individual user, allowing multiple people to go in at once. This is great for larger settings (like Halloween!).
Image by bkhurt
Tips and Tricks
- Safety: Do NOT look directly into a laser pointer! If you're building a laser maze, make sure the beams are low to the ground so kids can't accidentally blind themselves.
- Viewing the laser beam: Lasers are perfect for security systems because you can't see the beam, only the point on the other end. However, if you're making a laser maze, you want to be able to see where you should step. Using a fog machine can eliminate this issue and add extra ambiance.
- Mirrors: If you want to make your maze even more complicated, you can add mirrors to reflect the beams back and forth. This will allow you a harder maze with fewer lasers. Consider having different levels of difficulty and changing the number of mirrors for each.
- Cables: To place the lasers and sensors all over the room, you'll need extension cables. Consider buying a cheap phone cord and cutting off the ends so you can just use the power lines.
- Photoresistor sensitivity: Since photoresistors are so small, it can be difficult to aim at them from across the room with a tiny laser pointer and still expect to hit them. To solve this problem, you can put the photoresistor inside a cardboard tube and cover the opening with tissue paper or tracing paper. This will amplify the light source and give you more room to aim.
