DIY Laser Tag System (Revamped)

   Here's one of those classic games you probably played with your friends as a kid at birthday parties, mock-up military training, or just hanging out with your buds. You probably play this with your friends still, but it's a pain to keeping paying to get only a few minutes of shoot-em-up fun. Why not build your own system and play whenever you feel like it? Well, this instructable will show you how to create your very own system, from simple to arcade-style complexity. I do not recommend this project to those without some of the supplies listed in the next step, because it tends to get very expensive fast if you don't have the stuff (don't worry if you have some of these, most are pretty cheap to buy at Radioshack). To those who don't the money or supplies, I suggest buying the kids laser tag systems you can find in Toys R Us for about $20-$30. However if you have the hankering for learning circuitry, have spare time and friends you don't know what to do with, or if you just wanna build something, this is for you!

Step 1: Price and Supplies

I'm a big fan of cheap stuff so I liked what I saw when I tried designing my own laser tag system and found I had most of the parts I needed to mimic an arcade-style system, though the more complex I got with the designs (for example designing a Who-Hit-Me display) the more expensive they became, but my simple design is sufficient and is fairly cheap to replicate (for multiple players). Below is a list of prices and supplies you're need (unless it says 'opt.' which shows which parts are optional) to complete your own laser tag suit. Parts listed as being optional are things you don't absolutely need to make the system shown in my photos (though you can get even simpler without the buzzer). The following prices (and supplies) are based off local Radioshack prices:
(opt.) x2 $.48 8 pin IC socket
(opt.) $.99 14 pin IC socket
(opt.) $1.99 perf board (these 1.99-cheapies should have enough holes)
$1.99 piezo speaker (some higher dB speakers are more costly)
$1.49 .01 microfarad cap
$.99 10k ohm resistors (5-pack)
$.99 65k ohm resistors (5-pack)
$.99 100 ohm resistors (5-pack)
$2.99 CdS photoresistors (5-pack)
$3.99 5mm tactile switch
(opt.) $3.99 SPDT toggle switch
(opt.) $1.49 trimmer resistor
(opt.) $3.99 pager motor ("rumble" motor)
(opt.) $2.99 breadboard
$2.99 assorted LEDs (20 pack - cost effective if you want to make more suits)
$1.69 LM555 timer chip (8-pin)
$3.69 (@ Walmart) Laser pointer or bright flashlight (sensitivity will be explained in the build and explanation sections)
Wires and/or alligator clips, 9v battery clip
9v battery

If you have ABSOLUTELY NONE of these parts these are the costs (not including batteries and wire).
(simple: $19.80+tax)

If you have recovered from that price induced heart attack, remember it's only if you're missing everything, it goes down significantly if you have most of everything.

Comments

[TheGreatO]

Hi, really great instructable, I've been looking for something like this for ages! One question, do you know what the power or class of the laser you used is? I live in the UK and so sadly can't get one of the Walmart lasers you used :P
Many Thanks
The O

[liamandkobe]

Hi, fantastic instructable. How would you make it recieve ir light. Would you just change the LsR to a phototransistor?

[danny9893]

Finished the circuit but the photoresistors don't seem to do anything. Both the led and the speaker automatically turn on without a laser and the switch won't shut if off. help?

[GameNox]

Try putting it in a dark area. Many things can put of photoresitors like TV remotes.

[carmaster]

Any chance you can add a schematic for the whole system?

[jensenr30]

WOW! dude! this is super-in-depth! 5 star instructable! amazing job!!

[Revolt Lab]

Could you please post a fully labeled schematic? I've set up this circuit as best i can 10 or 12 times but cannot get it to work!

[Lance Mt.]

Thinking about doing something very similar using the COM-ports on our PCs during lans. Tossing up between simple radio or other means. I means a simple set-up can be carried around and all code can essentially be done at the pc and the network around.

What do you think?

[MadBricoleur]

I've been looking around a long time for instructions like this :) that make a simple laser tag system without milestag/fragtag cores (simply because that's out of my budget)! problem is, without using ultrabright IR leds and IR (only IR) receivers, are these as effective? I mean, can this hit 100 feet or so away, accurately enough for say, a sniper game? If they aren't, could you give me some sort of modified circuit for that? Sorry, I'm not that experienced with electronics myself, but I do know how to solder, and I do really want to make something like this...

[MacDynamo]

Well, a high output IR LED could probably work (haven't tried it myself yet) but keep in mind, when you set up the arena you're going to want to avoid infrared light sources such as fluorescent lights and TV (or Wii) remotes. Trust me, you don't want to be shot in the head when your dad changes the channel. I'm not saying you should stick completely with laser pointers but it allows you to do "stealth-hunting" in complete darkness with IR goggles as well as guerrilla warfare in normal light, where IR would have trouble.

[MadBricoleur]

oh, and would you happen to know what the guy means when he says "ac coupling of the trigger signal" http://www.electro-tech-online.com/general-electronics-chat/41201-40khz-ir-emitter-tagger-2.html here? I don't understand the instructions he's giving. I'm following the schematic for the monostable 555 at http://freespace.virgin.net/matt.waite/resource/handy/pinouts/555/ this site, but I don't see how that would work out.

[MadBricoleur]

I read about vishay tsop 4840 IR demodulators/sensors, which supposedly would help with filtering out sunlight and interference from other IR sources (since it only receives 48 kHz signals). There is a vishay tsal-6100 IR LED to go with that, with a 555 timer circuit outputting a 48 kHz signal to the LED to blast at that frequency. Plus, this isn't exactly milestag. Milestag firing (LED) and receiving (Sensor) parts, sure, but you don't need the whole microprocessor deal, because you can go old school, like this guy http://www.laserforums.com/forum/showthread.php/3548-DIY-Infrared-sensor-circuit (scroll down) did. Of course, add a focal lens assembly deal too, and you got yourself a 80m+ shooting gun and sensor. This all makes it a little more complicated (even I don't understand everything 100% as of yet) and you'll have to buy the vishay parts on mouser or something, but I guess you have less risk of hitting someone in the eye with a laser pointer, and you minus the cost of a laser pointer (the cheap ones don't even shoot that far), all the while getting pretty impressive range... what do you think?

[Madrias357]

Um, I would have to say that a cheap, effective Laser Tag system to be accurate like that would have to use cheap laser pointers, but it could be done. Yep, Photoresistors and laser pointers should get you accurate weapons. Just remember, then you have to kinda hit the PR dead-on.

[gungeek]

um just wondering cause this might be obviouse but im just getting started :P but if i wanted to have multiple PRs would i just have to connect them to the same circuit or build multiple ones? and if i can have just one circuit do i have to hook them up in series or paralel?

[MacDynamo]

I'm assuming you're looking into a cluster of PR's to make a larger target area. The good news is you can keep the same circuit when you add the other PR's. You'll want to add the extras in parallel (tip: you'll probably want to cover the bare leads in electrical tape and then bundle them all together with more electrical tape, think of it as a bouquet of PR's) You may want to use a potentiometer to adjust the total resistance so that day light doesn't activate the switch. Hope that helps you and good luck learning electronics.

[gungeek]

thanks so much :) that actually helps alot

[Madrias357]

Just out of curiousity, what's the resistance of your Photoresistor? I need one to pull (in the dark) 5v to 0v read by the chip, yet jump to near 5v to trip the pin high (I'm doing mine differently with hit-lockout and buzzers tripped by a 74LS74 clocked 'D' flipflop) I've looked and can't find the specifications, and as I'm building a few dozen, I need to order a small amount of the same ones.

[MacDynamo]

Good question! I'm using the 3/16" photoresistor with 4 "ribs", with the variable resistances of 1.4M ohm in complete darkness, 2k ohm in ambient light, and 400 ohms in bright light. If you're looking for roughly 4 microvolts then this is a perfectly fine photoresistor to use, but you really want 0 volts you may want to use the 3/32" photoresistor with 3 ribs which in total darkness which (according to my multimeter) creates infinite resistance (or basically >= 10M ohms), 4.2k ohm in ambient light, and a tiny 300 ohms in bright light. Depending on whether you mean less than a volt or "true" 0 volts you have two options. I don't know much about the flip-flop circuit you're working on so good luck with that! Hope this helped clear things up!

[Madrias357]

Needed to be below 2v, but I'll use the 3/32, I think. I like the sounds better as 4.2k shouldn't set off the alarm, though can you measure the voltage across it for me, from 5v if possible? (a hint: 4 rechargeable batteries is about 4.8, or 6 from standard ones)

[MacDynamo]

While I didn't actually use a multimeter to measure the voltage (mainly because my multimeter broke, rather unfortunate) mathematically it should be fairly easy to figure. For your 5 volt circuit (which is luckily the maximum voltage your 555 timer can take) and a 3/32" photoresistor with 3 "ribs" then your voltages at the three stages are: -infinity (somewhere close to or less than picovolts), 1.2 milivolts in ambient light, and 1.7 centivolts (if that's actually a term) in bright light. In case you're wondering how I got those calculations you take your voltage and divide it by the resistance (5/(infinity); 5/4,200; 5/300).

[Madrias357]

Oh, it's not a 555 timer I'm working with. I'm not really following your design, but a minimalistic design with a few added features. That, and a chip I've grown kinda fond of: a Clocked D-type FlipFlop. Though I'm using the 74LS74 as a Set-Reset-Latch, which merely remembers whether it was last set (light trips PhotoResistor) or reset (pushbutton depressed) and acts accordingly (light sets off buzzer, locks out trigger; button shuts off buzzer and feeds 5v to trigger switch) I call it "Hit lockout" so that someone that just got shot can't shoot back until the button's pressed.

[cdousley]

This would be fun with about 300mw lasers
lol

[Madrias357]

Yep, then you don't even need target boxes.  Just shoot your friends on the arms and leave burn marks.

[cdousley]

XD

[sxdemon]

Fairly simple and cheap.

Great work!

[MacDynamo]

I was actually thinking about adding a circuit for a laser gun using ultra bright LEDs or maybe a laser diode but haven't gotten it figured out quite yet, when I do I'll put it up. As for the extra sensors all you need is 3  (or more if you want a bigger area coverage) photoresistors wired in parallel with the one on the main circuit board and another resistor to replace the 10k resistor to balance the sensistivity (the resistances in parallel would be smaller according to Ohms Law). Hope this helps you!

[Madrias357]

You know, now I gotta build one!  I've just got to decide how to power the gun to fire a beam of light at friends.  I want the guns removable from the suit, so someone could build their own design, and have it be compatible with anything I'd build.  That and 3 sensors so you can still get shot in the back.

And the more I think about it, the pile of Cat-5E cable I have here from our upgrade is screaming to me to use it.