Wearable glove micro laser tag tube

Thread Starter

ComputerSaysNo

Joined Jul 14, 2022
5
Hello.

I've all but finished building a glove based laser tag emitter for my youngsters, and have got stuck on one of the last hurdles.

I want to have the IR LED housed in a small box or tube that would be positioned on the back of the glove, but still be small enough so that the size doesn't make it flop about.

If I use a 3mm or 5mm IR LED, with a lens that is no wider than 10mm-15mm diameter, and the overall tube housing the parts is circa 20mm x 45mm, is that decent enough to achieve an IR beam spread of about 6-8 inches at a maximum range of 6 to 8 metres outside, in an enclosed mostly wooded garden with fairly tall overhanging branches?
 

Ya’akov

Joined Jan 27, 2019
6,278
Welcome to AAC.

Your specification for speed is unclear, is the 6-8" at 6-8m? In any case, the smaller the emitter the less output power it will have. You might be better off using an array to get sufficient luminosity down range.

You could use something like this with the 12mm PCB option. It's a 5050 SMD component and you can see there are four chips in it.

1657815340532.png
Or, if 5mm LEDs are really bright enough you might be able to get away using two or three and these things are cheap enough, maybe you could steal the parts that attach the LEDs.

1657815568812.png
 

ericgibbs

Joined Jan 29, 2010
16,021
hi,
I 'think' when he says IR he may mean Red, perhaps he would confirm.?

With the type have suggested, it is possible to unscrew the lens holder section from the main body and so modify the focus so that the horizontal beam spread can be set as a spot or a 'band' up to about 12" wide at 6-8mtrs.

In fact, just confirmed this by modifying one of that type.

E
 

Ya’akov

Joined Jan 27, 2019
6,278
hi,
I 'think' when he says IR he may mean Red, perhaps he would confirm.?

With the type have suggested, it is possible to unscrew the lens holder section from the main body and so modify the focus so that the horizontal beam spread can be set as a spot or a 'band' up to about 12" wide at 6-8mtrs.

In fact, just confirmed this by modifying one of that type.

E
You wouldn't know from the name but laser tag guns don't use lasers, they use modulated IR.
 

Thread Starter

ComputerSaysNo

Joined Jul 14, 2022
5
Sorry for the delay in replying. My turn in picking my little ones from school and getting them settled. Why are kids always more hyper after school than before?

Afraid you've got me on the tech speak, as my electronic understanding is still at the newbie stage. I have slowly been building on my knowledge but it's a slow learning curve.

It think I may have already found my answer after accidentally stumbling upon a video and blog https://sir-ivanhoe.blogspot.com/. Discounting the airsoft gun platform used, the actual LED focal tube section and materials needed appears to be a perfect solution and within my size restraints.


And as luck would have it, I've just ripped apart an old small binocular set and have a fair few lens.
 

Ya’akov

Joined Jan 27, 2019
6,278
Sorry for the delay in replying. My turn in picking my little ones from school and getting them settled. Why are kids always more hyper after school than before?

Afraid you've got me on the tech speak, as my electronic understanding is still at the newbie stage. I have slowly been building on my knowledge but it's a slow learning curve.

It think I may have already found my answer after accidentally stumbling upon a video and blog https://sir-ivanhoe.blogspot.com/. Discounting the airsoft gun platform used, the actual LED focal tube section and materials needed appears to be a perfect solution and within my size restraints.


And as luck would have it, I've just ripped apart an old small binocular set and have a fair few lens.
I hope it works out for you. If you encounter any difficulties, please don't hesitate to come back and ask.
 

Thread Starter

ComputerSaysNo

Joined Jul 14, 2022
5
Before going down the road of building a bespoke IR LED emitter, I used an old DVD remote with an 80mm x 20mm tube taped over the remote's IR LED, with a 15mm plano (I think it's a plano) convex lens on the end from that pair of binoculars. I then built a simple IR remote tester like the guides you can find aplenty on youtube. I was using a TSOP31238 as the receiving unit but with the additional bit of hardware to include a buzzer, as seeing an LED for my eyes in daylight at distance is not easy. Buzzer - I can hear that.

No point testing indoors as the IR bounce is horrendous. We've got mirrors everywhere. So went outside instead. Pretty damn good results for a quick bodge job. Placing it next to a wall gave quite a bit of IR bounce, so placed it in front of a hedge and from a distance of about 4 ish metres, was able to wave across to within 12" or so of TSOP before buzzer sounded. Not bad.

Next tried a shorter 50mm tube but with a 20mm lens from same pair of binoculars. Got a range of about 5 or so metres and within what also looked like 12" from TSOP before buzzer sounded.

All in all pretty good results from something knocked up and held together with gaffer tape. A good starting point to investigate further.

Going to go back out again later but this time correctly measure out distances and detection angles etc to see if I can get that detection beam spread a bit more dead on.
 

Ya’akov

Joined Jan 27, 2019
6,278
Before going down the road of building a bespoke IR LED emitter, I used an old DVD remote with an 80mm x 20mm tube taped over the remote's IR LED, with a 15mm plano (I think it's a plano) convex lens on the end from that pair of binoculars. I then built a simple IR remote tester like the guides you can find aplenty on youtube. I was using a TSOP31238 as the receiving unit but with the additional bit of hardware to include a buzzer, as seeing an LED for my eyes in daylight at distance is not easy. Buzzer - I can hear that.

No point testing indoors as the IR bounce is horrendous. We've got mirrors everywhere. So went outside instead. Pretty damn good results for a quick bodge job. Placing it next to a wall gave quite a bit of IR bounce, so placed it in front of a hedge and from a distance of about 4 ish metres, was able to wave across to within 12" or so of TSOP before buzzer sounded. Not bad.

Next tried a shorter 50mm tube but with a 20mm lens from same pair of binoculars. Got a range of about 5 or so metres and within what also looked like 12" from TSOP before buzzer sounded.

All in all pretty good results from something knocked up and held together with gaffer tape. A good starting point to investigate further.

Going to go back out again later but this time correctly measure out distances and detection angles etc to see if I can get that detection beam spread a bit more dead on.

Now that you know it works, consider using a flashlight to test the pattern. Visible light is a lot easier to see :).

Do try it without the lens. In photography we use something called a "snoot" with is basically a tube please in front of a light to narrow the beam to a spot, no optics involved. The length of the tube affects the size of the spot.
 

ericgibbs

Joined Jan 29, 2010
16,021
Hi CSN.
In a darkened room, your mobile phone camera should be able to see the IR signals.
Try bouncing the beam back from a mirror, in a darkened room, to your phone camera.
E
 

Ya’akov

Joined Jan 27, 2019
6,278
Hi CSN.
In a darkened room, your mobile phone camera should be able to see the IR signals.
Try bouncing the beam back from a mirror, in a darkened room, to your phone camera.
E
Unfortunately, newer phones have much better IR cut filters and basically can't see remotes any more. I was disappointed my shiny iPhone can't see IR remotes. Others with newer phones report the same.
 

Thread Starter

ComputerSaysNo

Joined Jul 14, 2022
5
Not long finished testing it outside again. Surprisingly quite good when opting for the 15mm lens version, even when I shortened the tube down to 40mm. 20mm lens was quite horrific in beam spread. Maximum range I got from a dead on aim with the remote/focal tube/15mm lens to TSOP was just over 18 metres. Pretty good and well over what I actually need for the little ones. Obviously though, the further away I was the wider the beam, and that worked out to be about 2ft either side of the TSOP. I then decided to try and cut the beam spread down by placing some tape around the edges of the lens so that only 8mm-10mm of lens was actually visible. That reduced the beam spread further so that I was able to get within what looked like 10" of the TSOP. I then decided to place tape on the TSOP itself so that only a small portion of the sticky out curved bit was exposed and reduced it's angle of transmission down, and surprisingly I had to get an almost dead nuts on hit to sound the buzzer, or at the very least it must have been about 6" away from it.

I think my best option now is to 3D print a few tubes up to specifically house the 15mm lens, along with some discs with various sized holes that I can place over the lens to see which sized hole works best. I'll also print out a flat surface with a small slit in it so only a small portion of the TSOP can receive any incoming signal, see if that does owt.

I did try a few other techniques with the TSOP, such as having it facing sideways or topside facing towards me, and in fairness the topside method required a dead nuts hit at most distance to sound the buzzer when coming from one side, but when coming in from it's sensor facing side it picked up quite far away.

@ericgibbs @Ya'akov Ref camera, afraid my camera can't see an IR beam from a 950nm LED. It can see a very faint purple haze if looking directly down at it, but sees nothing when looking for beam spread on a wall. Though my camera can see a 780nm laser module spread quite well. Very weird.

Trying it in a tube without a lens sounds interesting. Am I right in thinking that would provide a tighter beam spread due to no lens helping to push it outwards?

Or maybe a lens further down the tube to get best of both? Hmm....
 
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