would those get off the scale readings from line trackers? what we’re trying to make is laser tag. dragonflyer221 just wants to use a red laser pointer and light sensor,whereas i think although we still have the red laser pointer for aiming we use the above infra red laser pointer for actual tracking.
if we do use the above sensors, do you think we could
A. integrate them into vex, and
B. detect them?
for part b, what should I use? will line trackers work? how would I read an infra red receiving ED? should I get an infra red specific sensor?
edit: also, will the infra red laser pointers appear on video? we’re planning on having us watch 2 separate tvs with the robots having vexplorer cams mounted on them.
I looked at the price for infra red laser pointers on that site---- $200 minimum!
anyone know somewhere for really cheap focused infra red lights? not necessarily laser pointers, but focused straight
Radioshack sells infrared LEDs for a low price. They’re not lasers, but could probably be modified to a narrow enough beam. Also, I was under the impression that the Vex light sensor could pick up infrared, although I can’t say for sure because I don’t have one.
As for seeing them on camera, Best Buy as well as many camera stores sell fairly affordable infrared lenses. (Although I’m not really sure why I know that:confused: )
Most video and digital cameras don’t regularly pick up infared or UV. some have integrated lenses and infrared lights that can be switched on and off and allow night filming, which is pretty darn cool. But it does always appear to be in black and white when you use an infrared filter if that’s what you mean.
Back on topic:
Inside a laser, pulses of light bounce around inside a ruby rod with one end completely silvered and the other only half silvered until they align parallel to the sides of the rod and escape through the partially silvered end. http://science.howstuffworks.com/laser5.htm
you could do almost the same thing with an LED by placing it inside a mirrored container (such as an Altoids tin) and using a piece of reflected tubing to ensure that all of the light leaving the tin travels in (almost) the same direction.
The biggest difference between this and a laser would be that all of the particles in a laser beam are “in phase” meaning that all of the light particles are vibrating together.
The link I gave probably explains lasers better than me.
I have never actually done any of this by the way, so I’m only about 60% sure that it will work. (Although light does reflect very well inside an Altoids tin:D )
I just dissected one of the guns for a broken laser tag and found a bunch of nifty stuff; 4 limit switches, and led relay board with 5 red leds, and the ‘laser’- I can’t get it out, so I’m hoping its IR and guessing because of the price of this thing, its not a laser but a diode that is amplified. I also found out the probable reason for it breaking: there was no soldering, everything was glued 0.0
Also, the laser tags chest-piece has five receivers of whatever the gun emits, so even if its not IR I can receive the signal using those (hoping they’re vex compatible)
Since the game comes with 2 guns and armor sets, thats 2 emitters and 10 receivers
All of my video cameras (computers built in, sisters, parents) and TMSC’s (not my school but the school that has an FLL team I previously went to and a bunch of other competitions involving RCX NXT and vEx, tmsc.org) display UV as white, I thought it was something universal.
Ruby and silver? That sounds expensive! Of course the sodler I use has some silver in it…
I think all cameras that are based on CCD-imagers (pretty much all cameras these days) are sensitive to “near IR” unless they specifically filter it in their lenses. Near IR is what IR LEDs emit, and is what IR remote controls use. Pretty much every video camera I’ve every used sees the IR from remote controls just fine. Modern security cameras often include IR LED floodlights for night vision.
I have no idea about UV, though you don’t want to use this for your laser tag game because it can damage your eyes if you are not careful with it. If you do want to (carefully) experiment with it, Sparkfun sells some UV LEDs.
Oh, I was just mentioning UV because of some UV experiments I did at TMSC, and they appeared as whiteish-blue on video. Im most likely going with IR for laser tag, I believe thats what most professionals use.
Something VERY off-topic that I don’t want to start a thread about, does anyone know if the old game boy game Kirby Tilt ‘n’ Tumble uses in accelerometer?
I think they also use rapid pulses of light in their guns so that other devices like laser pointers don’t work. Otherwise it would be very hard to set the “no friendly fire” options that some team laser tag games have.
And yes, it would probably be VERY expensive, not to mention hard, to build your own laser.
I know that I am doing this project with you, but I thought that I might let everyonr know that when I went to Radioshack yesterday I talked to a guy about the IR LED’s and he said that they have a pretty narrow beam, so they should work.