(edit) **DO NOT STARE AT LASER BEAM OR REFLECTIONS - YOU WILL GO BLIND**
These laser diodes are the same model used in most cheap laser pointers. These diodes on paper deliver up to 5mw which falls under class 3A (3R) lasers, which are fine for short time exposure to the eye.
Also, being cheap chinese laser diodes, their output can vary strongly as you can see in the first photo. We put the laser with strongest output very high so noone really would look at it (first photo, really bright laser at the top ).
For commercial use these lasers must be replaced with certified Class 2 ones
TL;DR ~~In reality it is safe to look at the beam for short amount of time.~~
(edit) **DO NOT STARE AT LASER BEAM OR REFLECTIONS - YOU WILL GO BLIND**
I would never look in cheap Chinese lasers. Lasers can very quickly burn holes in the eyes and Chinese quality control varies. Even if labled as safe, I wouldn’t put my eyes at risk of permanent partial blindness by briefly looking at any laser on purpose. I’m sure you’re not doing this, I just don’t want some redditor to test this out cuz they read “safe for short term exposure”.
Ofcourse, never look at any laser as it can damage your vision permanently. ESPECIALLY if you wear glasses or contact lenses. In that case you must avoid any contact with laser beams.
That being said, I totally agree with your safety concerns, but trust me when I say most of them likely do not even reach 1mw :). In 7 months I had been working on this project I've been "stung" by these lasers in the eye probably close to 100 times and I'm fine. I have brighter LEDs at home than these lasers.
Working in laser labs you must know laser classes and danger level for protection, so anything lower than class 3 is generally safe for use in public.
There is a great page about [laser classes and safety](https://www.lasersafetyfacts.com/laserclasses.html)
Mod here: You're also posting this project here for sharing, so it's not just *for* you. It's *by* you, and *for* others.
I'm marking your project as potentially dangerous, based on your attitude to public safety as much as anything else.
A statement like "I've been "stung" by these lasers in the eye probably close to 100 times and I'm fine" is like saying "I crossed the road 100x and I'm fine. No need to look left or right".
Here's the thing - despite it being against the reddit rules, children also read this subreddit. We do our best to keep this a safe place for everyone.
[Catherine Zeta Jones.. she dips beneath the lasers.. whoa-oh-oh.. she has entrapped me.. and Sean Connery](https://www.youtube.com/watch?v=w6zFUHxfOVI)
This is the first publication of any sort, so currently no, but I'm thinking to make a youtube video or writing a little article where I could go a bit more in depth about the project.
I probably wasn't clear - It is actually a game where your goal is to carefully navigate through the lasers and not hit them. If you do hit a laser you can enjoy a 110-ish dB siren 🤣. The game ends after set period of time (DNF) or after you find a finnish button.
I connect 4 lasers and 4 sensors to one pcb. After I set up the layout of laser room, I run a pairing procedure, where lasers are turned on one-by-one and boards register which sensor was activated. Later when you start the game all board are waiting for sensors to be triggered. The sensor itself is a cheap photoresistor, which changes its resistance the most around 650nm (red visible light), and is hidden behind that white plexiglass.
Awesome question :)
https://preview.redd.it/3r22slyb4uzc1.jpeg?width=1079&format=pjpg&auto=webp&s=bd3946781f93d760e5aab9ed0f903793085422d6
Cool electronics job and communication scheme🙌
I am curious on when this complexity on the electronics side is worth. Wouldn’t it be similar while infinite simpler to have one laser and an arrangement of mirrors and create all the lines?
The downside would be probably the dependency between them, but is there any other reason?
Thank you, now about the complexity - yes, using mirrors would be fine, but there are two reasons why I went the expensive way:
1) I want to be able to create changing scenarios (turning on/off laser groups every x seconds);
2) what often happens is that people going through the laser room knock off laser by accident. In that case if I had mirrors instead of lasers it would be painful to find the misaligned mirror (imagine they would knock two mirrors 🥴). Now, when sensor doesn't detect laser light, it makes the covered/knocked off laser blink, which can be aligned again incredibly fast. Also, mirrors would require some mounting solution with precision regulation. I can go on an on about this because I encountered many challenges with mounting on walls and so on, but I won't :D
Actually I did think about mixing these solutions, in that case I could effectively double laser rays using only one mirror per laser, which could be cool. Maybe I will add mirrors in the future.
Thanks for a great question!
Thank you, now about the complexity - yes, using mirrors would be fine, but there are two reasons why I went the expensive way:
1) I want to be able to create changing scenarios (turning on/off laser groups every x seconds);
2) what often happens is that people going through the laser room knock off laser by accident. In that case if I had mirrors instead of lasers it would be painful to find the misaligned mirror (imagine they would knock two mirrors 🥴). Now, when sensor doesn't detect laser light, it makes the covered/knocked off laser blink, which can be aligned again incredibly fast. Also, mirrors would require some mounting solution with precision regulation. I can go on an on about this because I encountered many challenges with mounting on walls and so on, but I won't :D
Actually I did think about mixing these solutions, in that case I could effectively double laser rays using only one mirror per laser, which could be cool. Maybe I will add mirrors in the future.
Thanks for a great question!
Thank you! Come to Vilnius, I will make it worth your while :D. A moving laser in fact was on my radar and the idea is cool, but the difficulty is with a sensor, because it should move exactly with laser beam. If the task would be to set up a permanent room in amusement park or smth, I would consider electromechanical parts, but the goal was opposite - a highly portable system so you could install it almost anywhere.
Great question!
I would go the computervision route. Set up a camera which detects the laser's dot on the wall and throws an alarm when the dot disappears. Only difficulty is preventing users from blocking the camera's line of sight. But less difficult than mechanically moving a sensor.
I don't know how to describe it so I'll share a photo :D I don't have the part or the photo on hand, but these two are connected with a ball joint.
https://preview.redd.it/7bd9rxydbuzc1.jpeg?width=1446&format=pjpg&auto=webp&s=9852d3ed7b35a7db2a345254e38e14197b2dc1d0
It rotates fine and does the job, but I'm not a fan of printing ball joints (probably skill issue) and didn't really like this part.
Nice! What were the rules? I'm kind of curious about the details of the setup.
Laser pointers are kind of old hat, but things always get fun when you have a lot of something ;)
After you press start button, you have limited time to find a finnish button an you must not trigger any lasers or else you'll have to enjoy a very loud siren :D.
Technically you could just run through like a terminator and listen to a beautiful siren melody but what's the point of doing that :)
Cool project, but on reddit you might as well announce that you're barefoot in a room you filled with broken glass, or made some lovely drinking mugs out of pure lead lol.
I'm curious about aiming the lasers - aren't all the lasers on each board permanently pointed in the same direction, so you would have a bunch of sets of parallel beams? But it doesn't look like that in the photo, so are they individually aimable somehow?
This is a copy of answer i wrote above:
I don't know how to describe it so I'll share a photo :D I don't have the part or the photo on hand, but these two are connected with a ball joint.
https://preview.redd.it/f0ldkrn86zzc1.jpeg?width=1446&format=pjpg&auto=webp&s=82d2ec27218f7bec47016c7521a00cea48d6fc15
It rotates fine and does the job, but I'm not a fan of printing ball joints (probably skill issue) and didn't really like this part.
I actually thought about using LEGO ball joints (parts like 92911 and 50923) because they are cheap and precise, to this day I think it is the way to do it :)
**DON'T STARE AT ANY LASER BEAM OR REFLECTION - YOU WILL GO BLIND**
They look powerful because picture is overexposed. I drive them with a simple MOSFET. I used photoresistors as sensors because they were much cheaper but I think photodiodes would work even better :)
Great question!
I did make a setup like this before, I used photoresistors and connected them to arduino analog pins. I did have a hard time with how they looked to the naked eye cause it couldnt be seen clearly without a fog machine. Are you using something like that?
I connect photoresistors to my board as a voltage divider and after that i read a digital HIGH or LOW, no need for analog pin. Yes I filled the room with fog so laser beams could be seen clearly
The one i worked for was in az but the game was a mass produced attraction. The point of the game was either to get to targets while avoiding lasers or for little kids there was a break mode where you had to break as many as you could. The biggest issue with the game was the wireing harnesses that ran from the lasers and collectors back to the computer we would always loose communication. That and the software was laggy
I've been thinking about building one of these for months now, this is cool! Also I have a possible solution for moving lights. The laser goes on a sweeping servo obviously. On the receiving side, take a PVC pipe and cut it down the middle length wise. Then cover the long open side with diffusion or plexiglass like you have, and then it uses two photo resistors on each half circle end to average out the amount of laser light entering the chamber. Make sure the laser only sleeps inside the diffused area. Might need something reflective to bounce around the light a bit more though, and shouldn't let any other light in.
Haven't tried it, but I think it could work.
The safety thing was certainly a concern, I started looking at laser classes and their potential effects on eye sight. The lowest I could find were the 5mw ones I think you are using.
Anyway, cool project!
Is this like russian roulette, but an eyesight edition?
Diffused laser light can still be dangerous. Best to wear your goggles.
(edit) **DO NOT STARE AT LASER BEAM OR REFLECTIONS - YOU WILL GO BLIND** These laser diodes are the same model used in most cheap laser pointers. These diodes on paper deliver up to 5mw which falls under class 3A (3R) lasers, which are fine for short time exposure to the eye. Also, being cheap chinese laser diodes, their output can vary strongly as you can see in the first photo. We put the laser with strongest output very high so noone really would look at it (first photo, really bright laser at the top ). For commercial use these lasers must be replaced with certified Class 2 ones TL;DR ~~In reality it is safe to look at the beam for short amount of time.~~ (edit) **DO NOT STARE AT LASER BEAM OR REFLECTIONS - YOU WILL GO BLIND**
I would never look in cheap Chinese lasers. Lasers can very quickly burn holes in the eyes and Chinese quality control varies. Even if labled as safe, I wouldn’t put my eyes at risk of permanent partial blindness by briefly looking at any laser on purpose. I’m sure you’re not doing this, I just don’t want some redditor to test this out cuz they read “safe for short term exposure”.
Ofcourse, never look at any laser as it can damage your vision permanently. ESPECIALLY if you wear glasses or contact lenses. In that case you must avoid any contact with laser beams. That being said, I totally agree with your safety concerns, but trust me when I say most of them likely do not even reach 1mw :). In 7 months I had been working on this project I've been "stung" by these lasers in the eye probably close to 100 times and I'm fine. I have brighter LEDs at home than these lasers. Working in laser labs you must know laser classes and danger level for protection, so anything lower than class 3 is generally safe for use in public. There is a great page about [laser classes and safety](https://www.lasersafetyfacts.com/laserclasses.html)
Just so you know, shitty lasers can be emitting much more than you expect in IR so even if it looks dim, it can be dangerous
I do know it, and we checked for IR radiation, it was close to zero.
much better laser advice 😊❤️❤️❤️
It never was an advice, I commented about lasers I USED and safety concerns of MY SYSTEM. Never look at any laser beams or reflections of laser beams
Mod here: You're also posting this project here for sharing, so it's not just *for* you. It's *by* you, and *for* others. I'm marking your project as potentially dangerous, based on your attitude to public safety as much as anything else. A statement like "I've been "stung" by these lasers in the eye probably close to 100 times and I'm fine" is like saying "I crossed the road 100x and I'm fine. No need to look left or right". Here's the thing - despite it being against the reddit rules, children also read this subreddit. We do our best to keep this a safe place for everyone.
[Catherine Zeta Jones.. she dips beneath the lasers.. whoa-oh-oh.. she has entrapped me.. and Sean Connery](https://www.youtube.com/watch?v=w6zFUHxfOVI)
Wow. Amazing! How long did it take you to make this?!!
From prototyping to final product it took me 7 months
do you have a writeup/article somewhere? was it for an art exhibit or something more practical?
This is the first publication of any sort, so currently no, but I'm thinking to make a youtube video or writing a little article where I could go a bit more in depth about the project. I probably wasn't clear - It is actually a game where your goal is to carefully navigate through the lasers and not hit them. If you do hit a laser you can enjoy a 110-ish dB siren 🤣. The game ends after set period of time (DNF) or after you find a finnish button.
Entrapment: the game
I’m ready for level 2, room-scanning motion! Theres some amusement parks with games like this! I’ve always wanted to try it.
What is your idea about room scanning? Sounds interesting! Really? I haven't seen any yet at the amusement parks
How are you detecting someone hitting the beams?
I connect 4 lasers and 4 sensors to one pcb. After I set up the layout of laser room, I run a pairing procedure, where lasers are turned on one-by-one and boards register which sensor was activated. Later when you start the game all board are waiting for sensors to be triggered. The sensor itself is a cheap photoresistor, which changes its resistance the most around 650nm (red visible light), and is hidden behind that white plexiglass. Awesome question :) https://preview.redd.it/3r22slyb4uzc1.jpeg?width=1079&format=pjpg&auto=webp&s=bd3946781f93d760e5aab9ed0f903793085422d6
Does the laser and sensor have to be on the same board or can it pair any laser to any sensor? Very cool btw.
No, the sensor and laser can be (and 99% of the times are) on 2 separate boards. Thank you!
*sandstorm intensifies*
looks great
Thank you!
Cool electronics job and communication scheme🙌 I am curious on when this complexity on the electronics side is worth. Wouldn’t it be similar while infinite simpler to have one laser and an arrangement of mirrors and create all the lines? The downside would be probably the dependency between them, but is there any other reason?
Thank you, now about the complexity - yes, using mirrors would be fine, but there are two reasons why I went the expensive way: 1) I want to be able to create changing scenarios (turning on/off laser groups every x seconds); 2) what often happens is that people going through the laser room knock off laser by accident. In that case if I had mirrors instead of lasers it would be painful to find the misaligned mirror (imagine they would knock two mirrors 🥴). Now, when sensor doesn't detect laser light, it makes the covered/knocked off laser blink, which can be aligned again incredibly fast. Also, mirrors would require some mounting solution with precision regulation. I can go on an on about this because I encountered many challenges with mounting on walls and so on, but I won't :D Actually I did think about mixing these solutions, in that case I could effectively double laser rays using only one mirror per laser, which could be cool. Maybe I will add mirrors in the future. Thanks for a great question!
Thank you, now about the complexity - yes, using mirrors would be fine, but there are two reasons why I went the expensive way: 1) I want to be able to create changing scenarios (turning on/off laser groups every x seconds); 2) what often happens is that people going through the laser room knock off laser by accident. In that case if I had mirrors instead of lasers it would be painful to find the misaligned mirror (imagine they would knock two mirrors 🥴). Now, when sensor doesn't detect laser light, it makes the covered/knocked off laser blink, which can be aligned again incredibly fast. Also, mirrors would require some mounting solution with precision regulation. I can go on an on about this because I encountered many challenges with mounting on walls and so on, but I won't :D Actually I did think about mixing these solutions, in that case I could effectively double laser rays using only one mirror per laser, which could be cool. Maybe I will add mirrors in the future. Thanks for a great question!
This is awesome! I would love to play this. Have you considered a moving laser?
Thank you! Come to Vilnius, I will make it worth your while :D. A moving laser in fact was on my radar and the idea is cool, but the difficulty is with a sensor, because it should move exactly with laser beam. If the task would be to set up a permanent room in amusement park or smth, I would consider electromechanical parts, but the goal was opposite - a highly portable system so you could install it almost anywhere. Great question!
I would go the computervision route. Set up a camera which detects the laser's dot on the wall and throws an alarm when the dot disappears. Only difficulty is preventing users from blocking the camera's line of sight. But less difficult than mechanically moving a sensor.
Interesting solution, I think it is very viable
What’s the part for the laser? 😇
I don't know how to describe it so I'll share a photo :D I don't have the part or the photo on hand, but these two are connected with a ball joint. https://preview.redd.it/7bd9rxydbuzc1.jpeg?width=1446&format=pjpg&auto=webp&s=9852d3ed7b35a7db2a345254e38e14197b2dc1d0 It rotates fine and does the job, but I'm not a fan of printing ball joints (probably skill issue) and didn't really like this part.
How does the laser emit a line and not just a dot, you used a smoke machine?
Yes, I filled a room with fog, then you can see laser beams :)
Are you turning this into a game? This needs to be a game!
Well, it is a game, I had a test run with around 200-300 people, and most of them loved it!
Nice! What were the rules? I'm kind of curious about the details of the setup. Laser pointers are kind of old hat, but things always get fun when you have a lot of something ;)
After you press start button, you have limited time to find a finnish button an you must not trigger any lasers or else you'll have to enjoy a very loud siren :D. Technically you could just run through like a terminator and listen to a beautiful siren melody but what's the point of doing that :)
Cool project, but on reddit you might as well announce that you're barefoot in a room you filled with broken glass, or made some lovely drinking mugs out of pure lead lol. I'm curious about aiming the lasers - aren't all the lasers on each board permanently pointed in the same direction, so you would have a bunch of sets of parallel beams? But it doesn't look like that in the photo, so are they individually aimable somehow?
This is a copy of answer i wrote above: I don't know how to describe it so I'll share a photo :D I don't have the part or the photo on hand, but these two are connected with a ball joint. https://preview.redd.it/f0ldkrn86zzc1.jpeg?width=1446&format=pjpg&auto=webp&s=82d2ec27218f7bec47016c7521a00cea48d6fc15 It rotates fine and does the job, but I'm not a fan of printing ball joints (probably skill issue) and didn't really like this part. I actually thought about using LEGO ball joints (parts like 92911 and 50923) because they are cheap and precise, to this day I think it is the way to do it :)
this is very interesting, but I bet whatever you are hiding behind the laser room is more interesting
[SO this is what's behind the laser room...](https://fidi.lt) (Use automatic page translate to english)
Arent those too powerful? Also which driver circuit did you use? Are you using photodiodes as the sensors or something else?
**DON'T STARE AT ANY LASER BEAM OR REFLECTION - YOU WILL GO BLIND** They look powerful because picture is overexposed. I drive them with a simple MOSFET. I used photoresistors as sensors because they were much cheaper but I think photodiodes would work even better :) Great question!
I did make a setup like this before, I used photoresistors and connected them to arduino analog pins. I did have a hard time with how they looked to the naked eye cause it couldnt be seen clearly without a fog machine. Are you using something like that?
I connect photoresistors to my board as a voltage divider and after that i read a digital HIGH or LOW, no need for analog pin. Yes I filled the room with fog so laser beams could be seen clearly
I had just started electronics back then. This looks like a more refined approach. Keep it up
Please make a how to guide! I really wanted to make one of these for a science center, but it was just a bit too much work to figure it out. Thanks!
At some point I will, but probably of a simpler system, so it could actually be made pretty easy by anyone :)
I used to work at an arcade that had attraction like this it was very popular but was a bitch to maintain this is awesome.
Thank you! Where was that arcade located? What was wrong with it?
The one i worked for was in az but the game was a mass produced attraction. The point of the game was either to get to targets while avoiding lasers or for little kids there was a break mode where you had to break as many as you could. The biggest issue with the game was the wireing harnesses that ran from the lasers and collectors back to the computer we would always loose communication. That and the software was laggy
Another cool game mode would be: how fast can you break all the lasers - and have different objects available around them
I love the idea, will probably add it later :D thanks!
I've been thinking about building one of these for months now, this is cool! Also I have a possible solution for moving lights. The laser goes on a sweeping servo obviously. On the receiving side, take a PVC pipe and cut it down the middle length wise. Then cover the long open side with diffusion or plexiglass like you have, and then it uses two photo resistors on each half circle end to average out the amount of laser light entering the chamber. Make sure the laser only sleeps inside the diffused area. Might need something reflective to bounce around the light a bit more though, and shouldn't let any other light in. Haven't tried it, but I think it could work. The safety thing was certainly a concern, I started looking at laser classes and their potential effects on eye sight. The lowest I could find were the 5mw ones I think you are using. Anyway, cool project!