Radio Controlled LEDS?

[crazylegsmurphy]

Let me tell you about a dream.

When I was 6 years old I saw a few movies that I loved so much it made me want to get into the world of make-up FX. As the years went on, I took on projects that cost me thousands of dollars of my hard earned money. While all of my friends were out getting drunk and cruising, I was at home messing with plaster and fiberglass.

The funny thing was that back then, no one wanted to share secrets. There were only one or two really good books printed that explained things, and even then it didn't quite tell you everything. I eventually turned to the Internet (back then it wasn't anything like it is now however).

When I posted projects that I wanted to do on the forums I got people saying stuff like,

"You are dreaming.
The system is much too complicated for your first project. It is many different circuits put together and you don't seem to know about the problems any of them."

So what did I do? Did I give up, did I say, "Awww shucks, that person is right, I don't know what I'm doing, I should just work at McDonalds my whole life and accept I'm stupid!"

No, what I did was dive head first into the projects. I busted my balls, I learned what I could, I ignored the naysayers, focused on and appreciated the ones that were willing to help me, and guess what....that's right, I eventually made it as a Make-up FX artist and had a pretty fun career as one for a long time.

I'm new to this, but I refuse to be pushed off this project because "I'm dreaming." I'm on this forum because my hopes are that there are a few here that are willing to say, "You know what, lets find out what happens!"

If this totally fails, then so be it. I want to learn, have fun, and solve this problem. With that said, audioguru, I was told by many people that you were the "man to see". It appears that you're more interested in reminding me that I don't know what I am doing and less in trying to help me solve my problem.

So no offense, but if you're not willing to help, you're not adding to this conversation, and you're frustrating me. To all the rest of you who have put in your time and energy to help, I really appreciate all the effort you've put in truly.

If this project works then awesome, if it fails...then awesome....but I don't see the harm in trying.

 

[blueroomelectronics]

Audioguru knows his way around RF, I'd not brush off his comments lightly.
It's not a trivial project, you also don't seem to even have the basics of the design worked out such as your power source, what size does the device have (those photos show no scale but we assume they're about the size of a can of soda)

It's for a stage production, keep it simple. The stuff on Star Trek doesn't work either, it's a prop.

 

[crazylegsmurphy]

Audioguru knows his way around RF, I'd not brush off his comments lightly.

Brushing off his comments? Since when has "you're dreaming" been a productive way of dealing with anything?

If audioguru knows his stuff, then that's great, perhaps he could take the time to sit down with me on this forum and point me in the right direction. His comments don't add anything, and they don't explain anything. His comments do nothing but add negativity into the thread.

If he doesn't think it'll work, then that is fine, but perhaps taking the time to actually come up with a reason other than calling my intelligence and ability into question, might actually help the situation.

It's not a trivial project,

Never said it was. What I have been asking for is the simplest, most effective way to do this project. Did I ever say, "I have a Popsicle stick, a gum wrapper, and a budget of $8, help me McGyver something together!"

No, I said I'll do my homework, I'll learn what I can, I'll do what I need to do...but I need the help of you guys because without it, I'll end up going insane. I know some of you are probably specialists in this and when someone comes along that doesn't know anything, but has grand ideas it probably feels pretty insulting..."Who does this guy think he is...I spend years in school...yadda yadda!"

I get it, I work in a field where I get the same think. People want to make full size costumes, but haven't even touched clay before....but so what? It's not my job to make people feel stupid for wanting to try.

you also don't seem to even have the basics of the design worked out such as your power source, what size does the device have (those photos show no scale but we assume they're about the size of a can of soda)

If you read back, I have been trying to determine those basics based on everyones advice. I have done my best to explain what I want it to do, and am now exploring ways to do it.

I am sure I have said somewhere in this thread that they are roughly

diameter - 8-9 cm
height -15-16 cm

It's for a stage production, keep it simple. The stuff on Star Trek doesn't work either, it's a prop.

I'm going to say this one more time Blue, and I am truly sorry if it comes off a tad snippy. You have made it clear your thoughts on this being a prop. Trust me when I say I have the experience to do this in many other ways as you have suggested, but what you need to get past is that I am not interested in using those techniques on this project. My goal is to find a way to do what I am wanting to do using electronics so I don't have to use cords, actors, etc.

If you look back, I have used the term "devices" since the first post. The reason is that I want you guys to think in terms of them as electrical devices, not movie props for the exact reason you stated above. Once the term "movie prop" is used, then people stop thinking about them electronically, and start finding ways to to it like in the movies. Does it help to spell it out that I'm trying to make the Sankara Stones from Indiana Jones and the Temple of Doom, does that make this project any different? No, all it does is open the flood gates for people to suggest sticking a lightbulb in there, and having someone turn up the light off stage like they did in the movie....if I wanted to do that, I wouldn't be here as I could do that quite easily.

 

[Hero999]

Audioguru does have a point, this isn't easy, you need to learn to run before you can walk. Attempting a complex project for your first will only make you frustrated and disheartened as you spend ever increasing sums of money on buying components, connecting them together only to find it doesn't work.

Another way of doing this would be to rip apart a wireless door bell or remote controlled car and use the transmitting and receiving circuits. Someone back stage could be controlling the LEDs and all the batteries and receivers could be concealed in the costumes.

I still think ultrasound is the best way, accurately detecting short distances with RF isn't easy because the speed of light is so quick. Sound travels more slowly, so it's much easier to time the delays. I'd send a pulse to one LED which would immediately echo it and use the propagation delay to figure out the distance. The only downside is the resin but there must be a way to drill holes in it and mount the transducers after its cured.

 

[crazylegsmurphy]

[Attempting a complex project for your first will only make you frustrated and disheartened as you spend ever increasing sums of money on buying components, connecting them together only to find it doesn't work.

Actually, not really. I don't get frustrated when things don't work and I'm pretty alright with the budget IF I'm able to actually use the parts for something eventually. What frustrates me is when people feel the need to shove it down my throat that I don't know what I'm doing.

If this is a really complex project, then lets break it down. Tell me what I need to know part by part and I'll do my homework. The problem is that we're all still in the "theory" part of it, and everyone has different opinions as to what would work and what wouldn't.

Another way of doing this would be to rip apart a wireless door bell or remote controlled car and use the transmitting and receiving circuits.

Good idea, but why? Why would I go buy a bunch of doorbells and rip them apart hoping for the best? I'll understand even less then. Doorbells and such aren't exactly rocket science, so they have to be within reason to build I would guess. Again though, this is why I avoided calling it a "prop" because now people are thinking "stages" and "sets" and "actors" and that's not going to help things...THAT is more complicated in my opinion.

I still think ultrasound is the best way,

You're actually probably right...but as it's been said the resin is the problem it seems. Drilling holes in the resin simply won't work as it will ruin the entire effect.

So it seems it's coming down to RF, or IR....there is still some debate as to whether IR will have issue with the resin (one test said no, but that was just one test), nor has anyone been able to figure out how to make the distance thing work...so that is why I went the RF direction.

I have some people saying, "Yes, it'll work...it's pretty easy!" and I have some saying, "dude, this is impossible"....so I guess I just have to choose to believe it's possible until proven otherwise.

And I know I sound snappy today. I don't want to get all pissy about things, it's just that I would rather be spending this nice rainy day having some good, fun conversation about how to get this going and testing out some ideas instead of sitting here writing rants to people who just want to stomp on the project.

 

[nigelmercier]

Although I'm starting to think this is a troll, my suggestion would be to use induction coils, at 3 different frequencies. An oscillator could easily detect when it was being loaded at this range.

A bit like the devices you get in high-risk items in a shop.

 

[audioguru]

Easy??
1) Make a simple FM transmitter and see if it can transmit to an FM radio.
2) Make a simple FM radio and see if it is not overloaded by the many FM statios around and to see if it can pickup your simple FM transmitter.
3) See what happens to the frequency when the capacitance to the antenna of objects change the frequency.
4) Figure out how to detect the signal strength.
5) Figure out how to modulate and demodulate the different transmitters.

It might take you a few years.

 

[crazylegsmurphy]

Although I'm starting to think this is a troll, my suggestion would be to use induction coils, at 3 different frequencies. .

A troll? For coming on a forum with a project I want to do? That seems odd.

Originally I wanted to build a Min Mass Wireless Coupler. But after e-mailing the person who made it, they informed me that I would be hard pressed to get the range I needed, plus it was pretty directional.

I e-mailed him back and forth for a while, but it seemed that the idea wasn't going to fly, so I went on to where I'm at now.

Easy??
1) Make a simple FM transmitter and see if it can transmit to an FM radio.
2) Make a simple FM radio and see if it is not overloaded by the many FM statios around and to see if it can pickup your simple FM transmitter.
3) See what happens to the frequency when the capacitance to the antenna of objects change the frequency.
4) Figure out how to detect the signal strength.
5) Figure out how to modulate and demodulate the different transmitters.

It might take you a few years.

Good thing I'm only 30 then.

So aside from the unnecessary sarcasm in the post, there are seems to be a few issues to work out. It would be cool if the post was a little more positive, but I'll take what I can get at this point.

So it seems there are some things to overcome. This is the kind of thing I need to know so I can pick the best way of doing this. Maybe RF isn't the best solution, maybe IR is the way to go....

All I can do is ask questions to better understand.

1) Make a simple FM transmitter and see if it can transmit to an FM radio.

Ok, does anyone have a link to a known working FM radio schematic that I could work from? I have the one from you audioguru, does it work?

2) Make a simple FM radio and see if it is not overloaded by the many FM

It proably would be, that is why I'm asking if it might be worthwhile to send ID's from an MCU instead. I'm not sure how it works, but even if the FM signal was coming from a radio station, if the MCU can't "see" the ID, then it wouldn't light the LED's.

So it may get "bombed" with a strong signal, but only when the other devices come close would it get the ID, and then work. I'm not sure however how this would work in the real world...would the FM station simply overpower the ID, or confuse the receiver?

3) See what happens to the frequency when the capacitance to the antenna of objects change the frequency.

Ok, so how does one solve that problem? I have a little MP3 player (and I once got a radio in a box of cereal) that worked pretty good, they're pretty small too. What is different with those devices than the ones offered by the people on the net (like yours audioguru?)

4) Figure out how to detect the signal strength.

Someone please correct me if I'm wrong...but I have used the RC car analogy a few times. If I have an RC car, and I drive it out of range, the car isn't detecting the signal strength, it's just "looking" for the correct frequency. If I walk towards it holding the trigger, the car will eventually have enough signal to move again.

This was kinda what I was thinking with this. (with or without ID's) It seems that if the signal is a very short distance, then as the props are brought together they'll simply get a stronger strength due to the fact they're coming within the range of the transmitter. At that point the MCU, or the (AND switch, as I was told) would allow both receivers to say, "Oh..I see the two signals I'm looking for, tell the MCU to light the LED's.

5) Figure out how to modulate and demodulate the different transmitters.

Good idea. Any links, thoughts, ideas, knowledge you have for doing that on this project?

 

[blueroomelectronics]

I can think of no product on the market that does something similar to analyze or reverse engineer. Of the many hurdles you're going to face the 3 objects that sync up when 12" from each other is no cakewalk for someone that knows what they're doing. The only reason I can possibly see for you wanting to pursue it is it's part of a magic trick. But you'd still be better off with someone off stage pressing an ON button to fire up three RF receivers.
Kudos for the persistence though.

 

[crazylegsmurphy]

But you'd still be better off with someone off stage pressing an ON button to fire up three RF receivers.

Please go back and read my post above. The simplest way is doing it like they did in the movies, but as I have stated, my goal is not to recreate what they did, it's to learn, and to create what they were supposed to do.

Simply, the reason doesn't matter. I could be wanting to do it for my kids, so I can impress the neighbor, so I can feel good about myself, and so on. What matters is that I would like to do it, that it's important to me that I do it.

So, lets say that I wasn't new to this, what would the suggestion be? What if I was a military contractor asking this question because I needed it to keep my troops safe, what would the answers be?

My point is, lets explore how it could be done, and then worry about how to do it. If it's not even possible to do in our world, then it's pretty easy let the project go, you guys worry about that, let me worry about if I have the brain capacity to actually learn how to do it.

 

[crazylegsmurphy]

With all that said.

To all the people reading this that have ideas, please look past all this negativity and sarcasm.

I think I've made it clear my intentions, why I'm wanting to do this, and that I'm looking for any advice as to the best solution. I don't want this thread shut down because a few people are more interested in finding reasons why this project is not worth doing.

I am now going to move forward and no longer respond to posts that aren't helping to forward the project, are simply here to talk down to me, or make me feel stupid for trying. It's that whole if you can't say something nice thing your mom said. I welcome constructive, well thought out criticism, and concerns, but sarcastic nay saying isn't helping.

So, lets move on.

It seems there are some potential issues with RF. Does anyone have any thoughts on this, or solutions.

If we take a step back to IR, what could we do to get it to work? As I said, there may not actually be an issue with the IR going through the resin as some of the tests seem to indicate. If this is truly the case, is it possible to use IR to send signals (ID's), at these distances?

My main question is, how does one limit the IR range, or have the receiver detect the distance? I know with sound/RF it seems you can limit the distance via power, but light is not really the same is it?

 

[blueroomelectronics]

If you were a military engineer you'd have the resources and budget to build anything you set your mind to. Plus you would have the experience and credentials to understand the problem and hire the team you needed to get it done.
We're working for free here.

 

[crazylegsmurphy]

We're working for free here.

Correct, so my team is that of volunteers, and a good team is one that see the vision and work towards it. So if anyone is volunteering then I appreciate the help from those that are trying their best. The ones that are determined to make it known that I'm not experienced enough to even attempt it, perhaps they might like to take their posting elsewhere is all I'm saying.

One thing I was just thinking about is. I would be willing to compromise and have a 4th device that would be a receiver. It's not idea, but if all the devices were just sending out signals (or were receivers I suppose), then one "main" unit could control them all.

This wouldn't be ideal if the props were taken somewhere else (away from the main device), but if it helps to make it a bit more simple, that would be ok. The only thing I can see it helping is:

A. Cutting down on internal components. (needing only one transmitter/receiver per prop instead of 3).

B. Potentially eliminating the multiple signals. If one receiver just had to check for three props it might be easer than each prop having to detect two others.

I really would like to find a way to do it like I originally hoped, but if it can't be done, I'd be willing to accept this.

 

[Ubergeek63]

If you were a military engineer you'd have the resources and budget to build anything you set your mind to. Plus you would have the experience and credentials to understand the problem and hire the team you needed to get it done.
We're working for free here.

Well almost anything...I worked with an engineer who used to do missile design... some ignoramus PHD would not listen when he said it was not possible... so they delivered the prototype missile to him with the 4" diameter inductor next to the 3" diameter missile!

 

[audioguru]

Make a simple FM transmitter and come back here and ask why it doesn't work. Then you might learn something.
Then make a simple FM radio and come back here to ask why it is overloaded by all the FM radio stations all the time.
Then make some kind of signal strength circuit and come baxk here and ask why it doesn't work.
Then make a modulator and demodulator and come back here and ask why ....

 

[crazylegsmurphy]

Ok will do, but first I have two other questions.

-Who are the owners/mods/admin of this site?
-Does it give you pleasure to talk down to people who are trying to learn?
-Are you posting in this forum because you want to help, or because you want to drive me off so you can go back to doing whatever you do?

Actually all but the first question are rhetorical. Audioguru, thanks, but I would like to respectfully ask you to refrain from posting in this topic anymore if you're not going to contribute something of value. What you're doing is dragging this topic through the mud because of your own personal thoughts on this.

You're making my thread nothing more than a potential flame war which will probably get it locked because you're simply posting smug comments knowing that I'll defend them. If you are so great at what you do, then put your money where your mouth is and help, but if you don't have an intention of doing so, then I would like to ask you to please go find something else to do so I can get back to the task at hand.

Thanks.

Ubergeek, that sounds like fun. I have a total sidetrack question. When you design missiles, does an artist ever help with the process? Does the end result come from the way it needs to function, or does an artist actually work to make it look a certain way?

 

[audioguru]

I have helped thousands of NOOBs on these forums that do not have "a chip on their shoulder". They genuinely wanted to learn about electronics. They thanked me.

Does your simple FM transmitter work? Why not?

 

[crazylegsmurphy]

I have helped thousands of NOOBs on these forums that do not have "a chip on their shoulder". They genuinely wanted to learn about electronics. They thanked me.

Does your simple FM transmitter work? Why not?

And I would too if you were actually helping instead of "helping" by the use of vague, sarcastic filled, information with a bit of, "Good luck dreamer!" thrown in to make me feel like a complete tool.

Why does it not work. Well, it seems that the breadboard I was working on doesn't exactly make for a good platform to make an FM radio on because the metal in the board creates inconstancies in the signal. As well, it seems the way I laid it out means that I have messed with the way the "physics" of it work.

Something I didn't know yesterday, and now I'm learning. Someone suggested your schematic as it seemed a little better, so I'm looking at it trying to figure out why.

Either way....my point is...when you say, "Does it work, why not?" is like what my elementary teacher used to say to me. Why not, I dunno why not....but let me put it to you this way.

"Hey Crazylegs, I'm trying to make a cake, any ideas how?"
"Pffft, you've never made cake before ever in your life, good luck dreamer!"
"Well, I really would like too, any way you can help me?"
"Ya, go make a cake then tell me why it failed!"
"Well, ok I could do that, but if you have anything to add it would be great!"
"No, your dream to make a cake is funny to me, I want you to go mess up like 50 cakes, then maybe you'll see why!"
"uhh, ok, you really think that's the best way to go about this?"

In walks a friend,

"Hey, I hear you want to make a cake?"
"Ya, I really would!"
"Cool, few things, here is a good recipe, make sure your oven is set to 180 degrees, be sure to grease your pan or you're going to have trouble getting it out, and it's very important that you let it cool before you cut it!"
"Oh, cool thanks!"
"No problem, here are some cookbooks I can recommend to get you started. If you have any problems, come see me and I'll do my best to help!"
"Awesome, thanks, this is gonna be radtastic!

See the difference?

 

[Torben]

ARRL Handbook, dude! Get it. You won't be sorry. RF is a crazy field and at RF frequencies, just about everything in the signal path becomes an active part of the circuit--traces, bends in wires, the wires themselves--it's a lot to keep track of.

I don't think anybody is trying to impugn your intelligence or determination, but I'd have to agree that as far as jumping in heads-first goes, RF work is right near the top of the scale (if not right off the scale completely). I'm just a hobbyist who's been at this for a few years now; I'm fairly comfortable with digital circuits and some aspects of analog (mostly audio and control stuff), and I have the distinct impression that a project like this would take me quite a long time to get working.

And we do get a lot of people asking for the impossible here. While your project may not be impossible, I've never heard of anyone doing it, and I think it would be a challenge even for an experienced RF designer.

But you sound like you have the time, energy, and dough to throw at the problem. Just be prepared for a serious learning curve, and yeah, it's going to take a while.

I'd say, start really simple. Build audioguru's circuit (yes, he really does know his stuff, more than most) and pay close attention to the photo of the one he built--it's important. See if you can get that working. You'll also need to locate and build a suitable receiver circuit (er, duh). You'll also need to know about filters, signal sources, some about antenna theory, and so on.

Anyway, I'm rambling. As you get closer to realizing this dream I bet you'll find more and more help coming out of the woodwork, simply because a lot of people would be interested in seeing this sort of thing actually work.

Best of luck, and if at any point there's an aspect of it that I can help with I will certainly try.


Torben

 

[audioguru]

The difference is that you know nothing about cooking but want somebody to show you how to make a cake, a gourmet dinner, a delicious drink and some special desert. We don't think you can find all the ingredients.

On these forums we talk about how circuits work and why, not just design or find circuits for NOOBs who have a chip on their shoulder.

Are you the NOOB who tried Arron Cake's very simple FM tramsmitter? It is a child's toy with extremely poor performance when it is made on the recommended pcb. You didn't use the pcb and couldn't find parts for it.