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Topic: IR frequency (Read 3007 times) previous topic - next topic

Grumpy_Mike

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I will need the range of the IR to be somewhere in the neighborhood of 30-50+ feet.

Too far for an IR LED, you might have to go for lasers.

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I will only be using 1 gun so I won't need to worry about detecting different frequencies.

I don't think you understand about detecting different frequencies, one sensor detects one frequency, that's it.

floresta

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Too far for an IR LED, you might have to go for lasers.

If it's not too far then it certainly is borderline.  How far does your TV remote reliably work?

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Adafruit sells a device that transmits only the "OFF" code for every tv code known. You could use that and a photo... what a waste... 

Actually you might use this as a starting point since the TV-B-Gone (http://www.adafruit.com/products/73) is fairly high powered in order to get enough range so that the user does not get assassinated by his victims.  I would salvage the receiver out of an old TV, DVD player, etc.

Don

Grumpy_Mike

If it is a shooting game you need a colomated IR beam otherwise there is no game, just point in the general direction.

Docedison

the TV B gone is good for several hundred feet... according to Adafruit...

Doc
--> WA7EMS <--
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Docedison

so put a lense on it.

Doc
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

Grumpy_Mike

Not sure if you know too much about optics but that is not going to fix the problem.

DuaneB

How about 10 or more IR leds driven hard and installed at the far end of a long non reflective tube - I assume the non reflective tube will only emit a narrow beam ?

Duane.
Read this
http://rcarduino.blogspot.com/2012/04/servo-problems-with-arduino-part-1.html
then watch this
http://rcarduino.blogspot.com/2012/04/servo-problems-part-2-demonstration.html

Rcarduino.blogspot.com

TweakGeek

I am in the process of working on focusing the IR beam using a double convex lens.  I'm not looking for perfection here at this point.  This is for an art research class in which we have to use Arduino to create an "interactive" project.  This is definitely something I will modify in the future and get it to work better, however, at this point I'm just looking for a working product.  I'm against a deadline (not your problem, it's mine!) so I just need to get something working first and then I can work closer to perfecting it.

I will be working with an 'almost perfect' setting in which there should be no other IR interference (remotes, etc.) that can mess with the project.

I do have a TV-B-Gone that I built a couple of years ago.  I just bought the kit and assembled it so it's not like I have intricate knowledge of its workings.  It is definitely something I will need to look at as far as amplifying the IR signal.

I really do appreciate everyone's input because it is helping me think things through and see possible problems I'm not educated enough to notice.

Thanks!

Docedison

I don't think that the gun is the issue... a shooting gallery implies targets... AND Each one is going to NEED a photodetector. Radio Shack sells a device from TI that will take care of the targets nicely BUT the issue that I think every one has missed in a misguided attempt to display their electronics knowledge is that the OP has virtually no electronics knowledge and limited resources and is virtually incapable of following any direction provided here, as he has stated twice... Period. One Uno and a gun and targets??? The simplest thing I can think of is still involved... First can this device use a red laser diode??? those are cheap and rather easily modulated. The same for the receivers but anything I can come up with is hard to fit into the time and resource/technical restrictions... Old school parts that are simple to use and reasonable readily available/inexpensive. Software is going to make this thing Un Do-Able as he will need to build it all before he can begin to write anything. A 2 - 5 Mw IR laser diode makes the gun. Modulating the gun is easy too. The targets are no issue either but it is a hardware issue where the Uno is used only to collect and display the "hit" information form the targets. A NE556 will make the gun and the targets can be almost any IR sensitive detector... It would be easier if A red laser diode could be used as there is a Laser in every pointer and they are cheap. The Challenge is either collimating a wide angle beam to hit a small target... or a narrow beam to hit a large target. The other issue is the shooting gallery has yet to be defined and I have seen 'advice' from several people who seem to think that the missing information is unimportant... lets have the OP restate the conditions more formally and see if WE can arrive at a consensus for a solution to a restated set of conditions the range has been set... but I don't remember anything about target size and any movement (which would place conditions on response time and data collection.

Doc
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

AWOL

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. A 2 - 5 Mw IR laser diode makes the gun.

Great gun, shame about the nuclear power plant.
]:D

Sp. "mW"
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

TweakGeek

Doc, you are correct that I have virtually no electronic knowledge and limited resources, but I have no idea where you get the "virtually incapable of following any direction provided here" statement.

As I've stated before, all I need is a basic system that functions on a basic level.  I'm not looking for perfection right out the door.  Hopefully once I have a base system then I can upgrade and make changes and learn as I go.  I've gotten so much "expert knowledge" from this forum that I'm spinning around in circles.  EVERYONE is an expert and their advice is always better than the previous guy.  I'm trying to take all of the information and look it up to decide what will work best for me.

At this point, I don't have set specifications that I have to go by.  My plans were to have a gun that emits a pulse that is then detected at the target.  When the target detects the pulse, it will turn on an LED for a couple of seconds.  Right now, the "target" is just the IR detector mounted on a board and the LED is just over from it.  The target is stationary and will not be moving. 

If needed, it wouldn't be a big deal to swap out the IR receiver with a photoresistor and then place a laser in the gun.  The "blinding" issue of using a laser has been brought up, however, this "exhibit" won't be open to the public so controlling the safety of the laser isn't a big issue.

Grumpy_Mike

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I assume the non reflective tube will only emit a narrow beam

No sorry that will not happen. That is not how optics works.

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BUT the issue that I think every one has missed in a misguided attempt to display their electronics knowledge is that the OP has virtually no electronics knowledge and limited resources and is virtually incapable of following any direction provided here, as he has stated twice..

That never stopped us before in this forum, at least it gives the OP an idea of the magnitude of the problem. A lot of beginners can't distinguish between an easy project and a near impossible one. That is what we are here for.
To the OP you have probbly gathered by now you have your work cut out. You have two problems, the width of your beam and the sensitivity of your receiver. At these distances neither is a trivial problem.

Docedison

#27
Jun 22, 2012, 01:34 am Last Edit: Jun 22, 2012, 02:16 am by Docedison Reason: 1
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"virtually incapable of following any direction provided here" statement.

I apologize for that statement it WAS very much out of place. I did mean mW not Mw although it should have been MW had I intended Megawatts of energy..
and I apologize for my tone in general. I was in a great deal of pain and acted like an old bear. I would recommend a simple solar cell or LDR (Light Dependent Resistor) as a detector shaded from incident light and just a low power red or IR Laser as you can simply set the sensitivity easily. Pulsing or otherwise modulating the beam is for the scope of this exercise more trouble that it might return. I can provide a schematic of a "simulated" detector, that is I am not going to build it for you but provide a drawing that will work. It will use one cheap IC a 4000 series buffer and I know a trick or two about turning it into an amplifier and the 2 or 3 second led operation, net cost will be about $5.00 per detector the Gun you can do that is reasonably low tech. It will need a small solar cell or LDR for the detector and a 6 gate unbuffered package a CD4069UB, sorry but I just woke up and my mind isn't at full speed yet. There is a way to take an inverter package and make an amplifier out of it very simply with three gates the remaining gates will be a half monostable and two gates in parallel for the LED driver. the whole thing will fit on one of the Radio Shack Project boards and is simple to build inexpensively. You can use your Uno for data collection on the number of hits... a scoreboard totalizer might be a better description. Does this sound like it might fit your project goals better and in a better attitude as well?

Doc
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

floresta

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I did mean mW not Mw although it should have been MW had I intended Megawatts of energy..

Nit pickers of the world unite!!!  The capitalization or lack of capitalization of the 'W' is more of a grammatical error that will probably be overlooked or go unnoticed by everyone under 14 years of age and many who are older.  The capitalization or lack of capitalization of the 'M' is a technical error that makes a big difference to anyone who cares - especially if it pertains to the quantity that is commonly called 'Voltage' - and you stick your fingers across it.

Don

Docedison

Absolutely... these kids have never likely used their own digital voltmeters either... I do think the 4069UB thing will work, I made a sound detector with one and an electret microphone about 20 years ago, worked well. Of course one might make a similar device with a 4 section OP-Amp but that is a lot of work and parts... A "lineraized" set of 3 gates works well and the quiescent current was in the order of 25 - 50 uA, I used that to drive a 40106 or a CD74C14 which makes a much better half mono... but simplicity is the key here and I don't have a 4069 to test with unless I can get one from Newark... somehow I really don't care for either Mouser or Digikey. Few bargains and Retail prices on NOS really gripe me... I bought some gates from Digikey last year with 2003 date codes. China of better DipMicro from Ebay would be better at least they aren't representing the stuff as New. Dipmicro is Canadian and only takes 4 or 5 days to get here from New York. I just would like to make the guy happy as easily as I possibly can cuz thats my real reward. Being able to pass on what I learned is all I can do now and being "in the Hole" or "Under the Gun" was all I did for 45 years. Damn shame not to pass it on if I can. I did take that "Nit" as a joke as it was intended... Good to see that the "Nitpickers" are awake and trying hard to keep me on my toes. Good to remind me that I can make a mistake... once... or twice an hour <BG>

Doc
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

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