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Laser target designator


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I'm currently thinking of putting a laser target designator together for MilSim-ish games. So far, the simplest solution seems to be using one of those commercially available laser tag guns and the receiver for the "target". The Laser X 88016 seems like the strongest contender, it has up to a 60 meter range though annoyingly it does have a load of light and sound effects that wouldn't be desirable.

 

For the unit itself my thinking is to remove the guys of the "gun" and put them in an appropriately sized project box, with controls re-wired to switch on the outside of the box. I would also mount an optical sight of some description for aiming, either a inside the case, next to the beam emitter, or on a 20mm rail on top of the case, directly above the emitter. I'm not looking to accurately replicate a real world LDS, rather to make a reasonable "looks like". I am also thinking of adding a camera tripod mount to the underside of the casing, and buying a cheap mini-tripod.

 

So, my questions are, has anyone else tried anything like this? Did they run into any particular issues I should know about? With things like unwanted light and sound effects, what is the best way of disabling them? It's a long time since I took systems and control at school and frankly I sucked at it, but basic soldering is not beyond me. I guess using resistors with a similar resistance as the removed components would work?

 

Cheers!

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It needs to set off an alarm, or similar. I am also considering building something myself using an IR laser emitter and some kind of sensor. The issue with that is that it can't just be set off by any random laser as it would severly impact the balance of the scenario. Think one team has to laze and "destroy" something the other team is defending. Make it something that can be set off by any random laser aimer and you make the job of the defending team near impossible. Laser tag stuff has the advantage that it A. already has a detector and alarm system, and B. isn't tripped by whatever laser. That said, my knowledge of electronics is limited at best so maybe building something from scratch would be cheaper and less problematic.

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Well that is more or less my question. My understanding is that with things like laser tag the sensor is tied to a specific wave length and can't be set off by just any random laser, be it IR or visible light. As I say, my understanding of electronics is pretty basic but at a guess a standard light dependent resistor has a pretty broad band of light that it will react to, so using it in the day would be pointless as it would just set off an alarm as soon as it's exposed to sunlight. For the device to work it has to react to a very specific wave length, stuff like laser tag does all that work for you. Obviously the downsides are probably cost, and range, since these things generally don't work beyond 60 meters, and probably closer than that in daylight.

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Adapting Toy technology is not the ideal situation.  Most toys are designed not to harm kids (like holding a laser on their eyeball for the life of the battery).

 

Rather find the components that you need and go from there.

 

You need a photoelectric sensor and put it into a circuit.  From there you will need to develop it for your needs.  A sample of what you might look for, I don't know what you are trying to do exactly, so you will have to figure it out from here on...

 

https://cdn.automationdirect.com/static/specs/peselection.pdf

 

I don't know what you are trying to do exactly, so you will have to figure it out from here on...

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Apologies for butting in, but guges, I think ninja wants a setup where a specific laser causes a target to react, and not just any player with a dbal/peq/Chinese eye killer to set it off?

 

Basically the scene from 'clear and present danger' where chavez (was it him?) illuminates a target and a monster truck gets nailed with a cellulose-encased laser guided bomb at a cartel members' house?

 

If you were aware of that, sorry. Not trying to offend anyone here :)

 

Speelz edit

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Watching this thread. Our local club was looking for a prop like this also for their games.

 

Initially we had thought of a souped up/styled up paintball gun that way we could “mark” the target but ideally we wanted a laser or something but was apprehensive on the toys as the old laser tag guns used to not work so well at almost any distance. Considerd buyingg the current generation equivalent to the laser tag but nver got that far.

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One option (lifted from real laser designators I think) would be to have laser signal modulated and not just a beam. So instead of just beam you send out rapid-flicker beam spellin 'Boom' in morse, so the receiving target is not set off by any and all lasers.

Could be the Laser Tag systems use such, or just different wavelenghts, to differentiate the teams, at least back when I went totag years ago you couldn't shoot teammates vests out.

Would need a bit of logic in both designator and receiver, but is easily doable with arduino or such.

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Yeah, I shall have a look at how complicated that would be to build and programme (sadly electronics are still mostly in the realms of magic for me). I might ask one of my more computery friends for some help with that. The advantage of building something myself are likely price and range, since laser tag sets cost between £40 and £70, and only the more expensive end have what I would consider usable range for it to actually be a fun feature in a game. My thinking is that it has to be useable outside of AEG range, otherwise it will be too hard for the attacking team, and frankly kind of pointless. I do also have to consider sunlight, I live in the south of Spain so very bright, sunny days are more or less the norm for most of the year. That will degrade maximum range. Another advantage of a self build is the possibility of adding things like a time to target effect. It's not terribly realistic if the attacking team only have to laze the target for a second, having to do so for say ten or twenty seconds would add some realism and tension to the process.

 

Thanks for all the help and input so far! Hopefully this will actually come to something unlike most of my project ideas.

 

Edit: Annoyingly I have a raspberry Pi unused in the UK that would probably be pretty useful for this. However, I only really thought of this after flying back to Spain... oh well.

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Yeah, I've been reading up on it and people have made pulsed lasers using Arduino for things like small concert laser displays. In fairness it doesn't sound massively complicated, but it would require two Arduino boards. One thing I have figured out is that I can use photodiodes for the receiver sensor. Usefully these usually only pick up a specific part of the spectrum, so, theoretically I could have a sensor linked to an Arduino board that is programmed to trigger an alarm when the diode picks up a particular pulse. The photodiodes can directly convert light of a given wavelength to electric signals so transmitting the specific pulsed signal to the receiver Arduino would be fairly simple. Any information on Arduino clones? Source, price, etc?

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The boards are not very costly. Got one clone board and additional bits kit on my desk right now, with no idea what to do with it, but I might actually look at building a designator myself, and I could at least help you with the coding of one... :D

 

I think Arduino compatible boards (like SparkFun RedBoard that I have is around20 USD a board, which is not dirt-cheap, but nowhere near the price of LaserTag set to butcher.

 

One thing that occurred to me about the receiver, is that one could probably do some sort of 'hood to protect it from excessive sunlight and to make it more directional target, so not just 'hjsing that way' triggers it off.

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Good idea on the hood, though I'd want the receiver to be fairly omnidirectional to allow the attacking team to approach from any angle. But a kind of sunshade to stop it from being dazzled by bright sunlight is a good call. I will surely need help with any coding I have to do as I have literally no experience of that.

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If encoding a signal into the laser stream is too diificult, another solution would be to have it 'paintable' by any laser (so just a bunch of LDRs or whatever looking for a high value that any laser can supply), but in addition to that you could send an RF signal from the 'real' (i.e. the one they have to use) laser designator when the lasers trigger is down, which is really easy to do (lots of libraries available).

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So effectively have two switches? Yeah, that's not a bad thought. I will have to actually give some of this stuff a go, and before that get hold of an Arduino board or similar. I guess the game play issue with that is that you could have multiple players painting the target and the actual spotter team would only have to get within radio range, which could unbalance things. Conversely you might have a situation where the spotter team successfully laze the target but for whatever reason can't get the radio aspect to trigger the target, which would be frustrating.

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Some of those sensors on that sight has a specific "trip" range.  If the laser you use is NOT in the right wave length it doesn't set it off.

 

250khz, 25khz, 3000khz

 

Find a laser pointer (Red, Green, Blue/Violet...) that meets this range and you have a foundation for your project.  Receiver, transmitter.

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So, first off, thanks to everyone is contributing to this, it's really helpful.

 

Second, working ideas for the designator itself, including stuff I have gleaned from here and other places on the internet. I think having a pair of lasers, one visible to allow the operator to actually see where the thing is pointing. This would not be what sets off the receiver and would be operated by seperate switch, I'd probably have to make sure there isn't a cross over in wave length between this and the laser for painting the target. It would sit along side the IR laser so they hit more or less exactly the same spot at any range. An IR laser to actually "paint" the target. This would controlled via an arduino or similar. The arduino would be programmed to send a pulsed ON/OFF signal to the IR laser, my understanding is that you can do this with the same signals used to control motors, though the specifics of this are things I need to actually read up on. I would also need a MOSFET to actually switch the IR laser on and off, as arduino pins work on a lower voltage than pretty much any laser.

 

Third. The receiver. Have a bank of IR sensitive photodiodes to pick up the IR beam. These are more or less LEDs that work in reverse, so light produces and electrical signal rather than electricity producing light. Like LEDs they also work with a specific wave length of light, though from what I understand is that they're also sensitive to wavelengths bellow what their LED output would be, so a red LED being used as a photodiode is also sensitive to IR but not green or blue, green is sensitive to red but not blue, etc. The photodiodes should automatically convert the pulsed beam to an electrical signal, a second arduino board can hopefully be programmed to respond to that signal and set off an alarm, or even an MP3 player. I don't want to run before I can walk but it did occur to me that having something like a recording of an A-10 strike or similar would be entertaining.

 

P.S. Guges, just read your reply while typing. Thanks!

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Cool, I shall start researching options. I suspect the light wavelength thing needs more research. IR has the advantage that it's not visible to the human eye, blue, is as you say very uncommon in games, as well as being quite hard to see. I probably won't start proper work on this for another month at least due to lack of funds at the moment.

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