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I basically need a person detector. Sort of... Answered

Some friends and I have been playing laser tag a lot recently, We try to team up in Free For All but always end up shooting each other due to darkness. I was wondering, is there any way (Cheap) To build something that each person can have, one person has a device that sends a signal to the other person when about 20 feet away, and on the other persons device, it would vibrate or buzz or something to indicate that the other person is coming. So basically when one person is 20 feet away, all other devices vibrate. One sender, and the rest receivers. And they would have to be pocket sized. Is there any way of doing this?

My original plan was to use ElectroMagnetic Fields, one person has the detector, and the other, an EM Pump, But I could not find a pump design powerful enough for 20 foot range.

Please Help!



5 years ago

Wouldn't it be easier to have a distinguishing hit detection?

I don't know much about laser tag as I've never played it nor have I ever looked into the technology, but your gear needs to detect your hit somehow, doesn't it?

So instead of trying to build a radar that can find your friends I'd rather say you try to tweak the detection sensor and your lasers. Basically, have one team use lasers with frequency A and the other with frequency B with their detection sensors primed for the opposite laser type.

So what you could look into:
- Materials which change a laser's frequency (maybe per polarization)

- Materials which filter light of a certain frequency (again, possibly per polarization)

If you want to go with the localization route, maybe you can use your smartphones and their GPS to pinpoint the positions of your teammates and have them displayed on a map. Just google "friend locator map app" or something of the sort. Mind that phone GPS is not very accurate depending on the location where you're at. The good thing is, this system is basically for free, provided you have a smartphone.

If you want/can dish out a bit of money, there are locator tags for usage with cell phones as well, which usually can tell you the distance your tagged item/person is away, such as this one.


5 years ago

A device like that would not give direction, so you might not shoot an opponent you can see because a team-mate is close but out of sight, say, behind a barrier.

I would simply get your friends an LED armband, so can distinguish them visually.


5 years ago

This will be pretty hard to do - An LED behind a polarised screen will only be visible when you wear glasses with a similar polarised screen.

A simple slow flashing LED on the shoulder?

To do this with RF is a difficult thing - In general a short antenna gives short range, a simple low powered on off beacon - even a 555 timer running at a suitable frequency - may work for you but you won't get much in the way of directionality without carrying a fair lot of gear.