Special design for remote det.

[Tuatara]

It seems there may be a need for forum members to have access to a purpose designed radio control device, to assist with their research <img border="0" title="" alt="[Wink]" src="wink.gif" /> .

Being an EE, I could design such a system, and supply plans (for free), PCBs, kits or fully built systems. This is not an attempt by me to make shit loads of money, parts will be supplied at cost, though I may need to add a little something for a fully assembled system to cover my time. I don't think this is against the Rules is it?

So what do you guys want?

Range?
Frequency?
Output type?
Safety interlocks?

Anthony has already mentioned having two outputs, one delayed, so a warning could sound say 5-10 secs before the second output 'activates'. Piezo sounder could be built in.

Interlock could be a 3.5mm phono plug on a string - system is active only when plug is removed.

LED telltales on the outputs would probably be a good idea - so you KNOW the output is off before your attach your, umm, equipment.

[Anthony]

Good idea starting a new thread. You're not breaking the rules as you're providing your skills and services to theforum, adding something to cover your time is quite acceptable.

Range: I'd say 100m minimum in a wooded/urban environment i.e. non-line-of-sight. 500m should be achievable on a few deci-watts of output power with a decent areial.

Frequency: If possible not one swamped by other devices. Maybe an unused or reserved FM band?

Output: Since people will likely mount the PCB in their own case, it might be easiest if the outputs and inputs (including interlock/master switch) are surface mounted screw terminal block type connectors. People could then use whatever switches/interlocks/IO connections they wish.

IMO the unit should operate from 6-12vdc, allowing the use of lattern batteries, 6&12v gel cells, cars, and model car nicd/nimh packs.

The output could be low current to drive a relay of the user's choice. Aux car relays are cheap and good for 40A. Integrating one into the PCB would require some hefty tracks though! If a relay is included then current handling should be at least 10A IMO with a fused input to prevent blown tracks. A standard mains fuse would make replacements easily sourced.

Output status LEDs would be useful, as would a firing circuit continuity LED.

I suppose what I should ask is whether you're looking to provide an entire blasting machine that does everything, or a RC blasting machine driver which just provides a control signal?

Maybe it would simplify mounting if the LEDs/switches were on flying leads?

The main power I/O could also be on flying leads or on terminal blocks, like I mentioned above. Either way it allows people to use their preferred terminations. Be it terminal posts or spring clips mounted on their box, or flying leads with croc clips. Ditto input, croc clips for generic input, or crimped spades/rings or nicd pack connector for a permanently installed battery.

I've probably made this over complex, so I'll clear the floor and let someone else speak :)

[Tuatara]

Thanks for the reassurance re the Rules :)

Your suggestions are not complex! You should see some of the specs I have to deal with in my line of work :rolleyes:

More! More!

Lets get a real wish list going! The more information I have the better the end result will be. The whole point is to have some very happy (and intact :D ) forum members out there.

How about a self-destruct output (triggered by the remote) that could initate a high temp incendairy to remove the evidence should things become ... awkward.

One could also add a 'disable' output that blows a fuse in line with the battery, in case the experiment fails to fire.

Would you like to operate multiple recievers from one transmitter?

Incidentally, operating out of line-of-sight might be a little risky.

As for frequency, every country has free unlicensed band for such things as garage door openers and car alarms. You can tx anything you like as long as you dont use more than 10mW. Though upsetting the FCC is probably the least of your worries <img border="0" title="" alt="[Wink]" src="wink.gif" />

Typical bands are 305, 315, 433, 460, 860, 868 MHz I can cater for all.

[xyz]

What about having a re-useable receiver that could be placed say 10m from the charge and was connected to it with wires. This would stop you from having to make a new one each time as the wires would be damaged but hopefully the receiver wouldn't.

It would save having to use large lengths of wire for electris ignition, e.g. the receiver is 10m from the charge, you are 100m from the charge and you don't need to use 100m of wire.

Because the receiver is close to the charge, there is still some chance of it being damaged but it is much better to put the receiver at risk than yourself.

<small>[ February 28, 2003, 04:38 AM: Message edited by: xyz ]</small>

[Flake2m]

Why not have a circuit that uses a DTMF sequence so you could use a phone to set the device off? All you'd have to do is ring the receiver and then key in a 4 digit number and then BOOM.

This system is a bit more desirable because you dont need to make a transmitter. The receiver would need to have a decent range though, about 100m is good.

[Anthony]

The general idea is that the reciever is reusable :)

One thing I forgot to mention in my first post was about the warning alarm - you could include a piezo buzzer on the PCB, but it'd be nice to have that and/or the facility to connect an external alarm, as I was thinking of using something like a car/shed alarm siren. I would trust being able to hear a buzzer when I could be 10 yards away, near the charge on a windy day. Plus it'd be nice to hear it from your firing position to assure you that the charge is indeed going to go off in 5 seconds.

When you say that operating out of LOS, do you mean in terms of radio reception? If you meant not being able to see if someone had wandered into your blast site, then it's not a major issue as somone shouldn't be able to do so whether you can see them or not...

I don't think I'd use a self-destruct option, but other people might find it useful.

Could the emergency battery isolater function be done with a relay/transistor rather than a fuse? I'm thinking of something with a NO and to turn the relay back on and thus power the circuit again would require power on the circuit side of the failsafe, which obviously there can't be. On second thought, a fuse would be a lot simpler and they're not exactly hard to find or expensive and would only need replacing in rare circumstances!

Multiple transmiter channels would be good - a modular system :)

Incidentally, could the firing delay be adjustable? In some circumstances it would be desirable to have no delay, where precise timing is required, say for special FX or firework pieces. This in conjuction with multiple recievers might be good for things like FAEs. Have the bursting charge set to zero delay and the cloud detonator set to 0.1sec, and pressing both buttons on the transmitter at once.

I don't really give a stuff about the FCC and I doubt anyone else here does :D Considering these things would be used for &lt;1 second every other week or longer, I doubt the FCC would care much either. IMO cram as powerful transmitter into it as you feasible or as much power as can be drawn from a few AA cells. Would a few watts enable you to fire from the comfort of your living room? :D

[Tuatara]

Flake2m : I see what your getting at, however the 'receiver' would then need to be a cellular modem ($$$$$) or part of a cordless phone.

The whole point of this thread is to spec up a purpose designed radio control system - there is already a thread about using OTC parts.
BTW transmitters are just as easy to build as receivers!

Anthony: The emergency shutdown needs to be reliable, which is why I thought a 10c fuse in line with the batt. As you say, it should only be needed occaisionally.

Delay could be programmable - thats the advantage of using a microcontroller - you can do practically anything without changing the hardware.

One could go for more tx power, though more benefit would probably be gained from a better antenna. More power = $

I was think LOS from a safety perpective, though getting UHF to go over hills can be problematic. You'll get best range LOS.

<small>[ February 28, 2003, 03:42 PM: Message edited by: Tuatara ]</small>

[Machiavelli]

In case of an emergency shutdown, I'd like a good indicator that the shutdown has really happened, like a bright LED or a loud buzzer.

[green beret]

Yes! Definately, I would be very interested in purchasing this. I would be happy with a 100m non line of sight range and a reusable reciever. Apart from that I wouldnt really want anything fancy, just a good reliable system. Good work Tuatara. But whatever you come up with, put me down for one! Anthonys post would be an ideal system, yes, wouldnt it be fun to fire charges from your living room! :D It would give you an aliby too. Umm I was at home.....

<small>[ February 28, 2003, 11:15 PM: Message edited by: green beret ]</small>

[Energy84]

Anthony has pretty much covered everything I'd ever want in a system. Good work Tuatara. Put me on the list for beta testing <img border="0" title="" alt="[Wink]" src="wink.gif" /> :D

[NightStalker]

I would make the detonator controller independant of any receiver. This means that the controller should be designed to be connected to any device capable of receiving a signal, regardless of type, as long as it is a unique signal. It's purpose would be to process the incoming signal, determine if it was a valid control command, and if so carry out the command.

For instance, the controller would have screwdown terminal posts, to which can be connected any number of adapters, such as alligator clips/banana jacks/phono plugs/etc. This would allow it to be connected to pagers, cellphones, FRS radios, CB's, phonelines, etc.

Adding the ability to secure the controller against premature initiation would be desirable too. For audio inputs (like walkie-talkies) it would be DTMF (programmable via dip switch or PIC). For non-audio like pager, it could be receiving two seperate pages within a fixed time interval. Maybe even a pulse coded flash from a modulated laser pointer could be arranged.

A timer, both to arm the controller (safety), and to disarm (self-destruct?) if left behind, would be required. Optional anti-handling circuitry would be nice to to render it useless if one was forced to flee and leave it behind because of impending contact with police.

LOS is highly limiting. I'd rather be behind something substantial, like a hill or building, if I was setting off a large charge. And what about indoors? Lots of abandoned buildings provide useful target practice if you have a controller that'll operate in such an enviroment.

You'd want (ideally) highly directional to prevent signal intercept by scanners with nothing better to do. You'd want something readily available to anyone, regardless of location in the world (Forumites being global), and that can be made from readily obtainable parts purchasable in person from major chain suppliers like Rat-Shack (to avoid mail-order papertrails).

2.4GHz cordless phones and FRS radios are available anywhere, for cheap (or stealable), they offer DTMF possibility, decent range (my FRS goes at least 1/2 mile through two concrete block buildings), and are readily modifiable.

Status indicators would be good too. Be nice to know if the device was "ticking" when approaching a dud charge. Be very nice if the indicator panel was removable so you could leave the controller behind with no visible indicator of status to help people who might have contrary interests in not letting your device complete its function.

Multiple charge control would be very nice. :) Push 1 on your DTMF controller to set off charge #1, push 2 for....etc.

A PCB pattern would be great, but so would a wire wrap or perf board diagram for those who'd rather not etch a board (or solder). If you're offering to sell these, I'd be wary of buying it. Not only are you new here, but it could be considered arms trafficing, since it's intended and stated purpose is to control destructive devices and would be sent internationally.

Better for everyone involved if you post a "dream" of what you built for your own personal use, and just happened to share with everyone else here. <img border="0" title="" alt="[Wink]" src="wink.gif" />

In other words, teach us how to catch our own fish, rather than selling us the fish. :)

[Terry Collins]

Building remote detonation devices is easy. Making it SAFE is HARD.
You need a device which shows what's happening: power on? receiving signal? relay closed etc.

Go to the topic 'remote detonations' and you'll find such a device.
Also cheap and easy.

[Dunkelmann]

another idea for remote ignitions would be to use a relay that has an ethernet port. such relays are used in home or industrial automation and are readily available at moderate prices. you could use it to ignite stuff via the Internet from every point of the world.
or use it with a Wireless LAN accesspoint and a PDA or a Laptop.
this should give you a few hundred meters in the open, plus you can always make sure that the receiver is still reachable as the receiver can transmit information back to you.
the software would be something like Blaster Professional 2003 (yet to be written:))

if the receiver and transmitter are both microprocessor controlled, then the use of a module this one like
<a href="http://wireless.troygroup.com/wireless/documents/datasheets/TROYEtherWindPlus.pdf" target="_blank">http://wireless.troygroup.com/wireless/documents/datasheets/TROYEtherWindPlus.pdf</a>
is possible.

dkm

<small>[ March 01, 2003, 09:21 AM: Message edited by: Dunkelmann ]</small>

[zaibatsu]

Just wanted to say that this is a very interesting new topic.

I wouldn't be prepared to buy a PCB etc from you, but would be prepared to make an anon donation for the plans.

[Tuatara]

Nightstalker I appreciate your comment on shipping a remote detonator controller internationally, but thats not what it will be <img border="0" title="" alt="[Wink]" src="wink.gif" />

It will be a 'radio controlled switch' transmitting in the unlicensed control band, for use in gate openers, garage door controllers, lighting control, or whatever else the end user decides to connect to the terminals :D .
Radio will not be limited to LOS, but one must be aware that mountains will reduce your range.

zaibatsu - sentiment appreciated. I was planning on making the design available gratis to the forum. Just cos' I'm a nice guy!

Mr Collins (i hope thats not your real name!) I know making these things safe is hard. Thats why I thought of doing a special design, as opposed to cobbling something together out of dismantled doorbells. Rest assured I will do a LOT of testing before anyone here gets hold of my design. FYI Ive been a professional engineer for 15 years - doing hardware and software. I'll keep you safe!

[Tuatara]

Of course! I can even do a 48 bit encrypted, rolling code system!

[Tuatara]

Ah! Nightstalker I just figured out wht you meant about me being new here - I could be a spook infiltrating the forum, trying to locate its members and advance the war against terrorism. Fair comment. I'm not, but such an assertion counts for zip. There is no way for me to prove who I am without putting myself at risk.
So I'll do this as a 'Shareware' project, and provide assistance to builders via the forum

[angelo]

Multiple channels would be good.

But for those of us that might not want to use it for testing would most probably be looking at a cheaper yet easily manufactured product.
I don't mean cheap as in unreliable, but if you could cut out some components that aren't required e.g instant detonation (no need for a timer), no alarms, etc, etc. It would lower the cost of the end product.
Maybe a very easily customizable option would be the way to go. Were we could choose the components we want. If we want timers, or alarms, or multiple channels we can connect them.

Don't get me wrong. I like the idea. Just that some of us don't have a lot of money to spend, so if this costs say $40 a receiver, then we can't exactly make a shit load of them.

[Titanium]

I would be interrested too.
But there would be nice with some sort of warning when the charge is "armed"...

[Anthony]

I don't mind some extra features that I'd likely never or hard ever use as long as they didn't bump up the price too much. The extra flexibility might come in handy.

If the device runs around a programable micro, extra features might only cost a few extra pennies as most of the changes would be done in code using previously redundant capabilities of the micro.

For the dud emergency power down, the firing siren could sound for say 5 sec before blowing the fuse. Obviously when you hear the siren stop you know all is well.

Dunkelmann, I think an ethernet - dynamite adapter would be an entirely different device, but Tuatara can confirm/deny that.

NightStalker, How could a highly directional device operate effectively in non-LOS? Who would be scanning an unrestricted frequency and what would they do with your unrecognisable signal that only existed for &lt;1 sec?

Since a few people have raised issues concerning price, could you guesstimate a likely ballpark figure for this device, Tuatara?

BTW, I would be happy to purchase a complete 'radio controlled switch' from you <img border="0" title="" alt="[Wink]" src="wink.gif" />

[Tuatara]

Anthony is right about extra features - mostly they come free if they merely involve changes in timings, id codes etc.

Ethernet and wireless LAN is another beast altogether, worth consideration though, esp for a big PC controlled pyro display!

Off the top of my head, based on the parts I have ready access to, cost would be about NZ$10 for a transmitter with 4 buttons, and about NZ$15 for the reciever, with flying leads and no relays. Screw terminals are nice, but a bit pricey when a bit of PVC covered wire will do the same job. I've left the relays off, as the consensus seems to be 'let the user choose'. NZ$1 ~ US$0.55 at the moment.

This guesstimate is based on parts I can procure by skimming off bulk purchases. Individuals wlaking into their local electronics store could expect to double or triple the price. Yes, thats right, retail is a total rip-off.

Scanners are not a problem - the transmission only lasts for 1 second or less. For the same reason radio direction finding equip could not be used to find the transmitter location

[NightStalker]

"NightStalker, How could a highly directional device operate effectively in non-LOS? Who would be scanning an unrestricted frequency and what would they do with your unrecognisable signal that only existed for under 1 sec?"

Directional antennas can focus a signal, which is of a frequency capable of penetrating obstacles or bouncing off the atmosphere, for non-LOS control. 2.4GHz systems are rather directional, but are capable of going through walls, hence not LOS in the sense of needing a clear path with NO intervening obstacles like walls.

Scanner freaks listen in on all sorts of freqs for whatever purpose. Assume someone is listening in, and recording, anything you broadcast. While they may not know what it is at the time, if they hear that a bomb was set off at the same time as they heard some unrecognisable signal on an unrestricted frequency, than might they not put one and one together?

And who knows what the cops/feds might be able to do with that info. Transmitter "fingerprinting" has been done since WW2, so they might be able to use any such recorded signals to match a controller they find in your possession, connecting you to the explosion.

I'd want any dud warning to be silent lest it reveal its presence and be discovered and recovered.

A rolling code system to prevent accidential functioning by nearby transmitters, or pre-mature functioning by ECM (like the brits did to the IRA bombers), would be desirable, if cost isn't too prohibitive. I'd assume some sort of modifying of a car-alarm or garage door opener system?

I'd like my R/C system to be capable of being useable as a weapon controller, in "interesting times", as well as a general purpose blasting box the rest of the time. Hence the rather militaristic features desired. 'Course, a person would be prepared to pay more for these extra features. <img border="0" title="" alt="[Wink]" src="wink.gif" />

"Screw terminals are nice, but a bit pricey when a bit of PVC covered wire will do the same job."

True, but the screw terminals will never wear out, whereas the wire will eventually fray and have to be trimmed down, eventually being used up, especially since it's likely someone would be keeping this device for years and not as a one-time use item.

Ever done any telco work? I've got some ideas for some circuits if you'd like to try something different.

[angelo]

Ok so we have the estimated price. Now if its not to much to ask what is the estimated size?

Is it possible to make it using multiple circular PCB boards so that it could fit into the end of say... a pipe?

<small>[ March 05, 2003, 01:12 AM: Message edited by: angelo ]</small>

[Tuatara]

I was thinking rolling code already - I've got a license for the Microchip system. This uses a 32 bit rolling code, with a 28 bit fixed serial number, encrypted with a 64 bit key. Rather hard to spoof I'd say. It has four button inputs so you can tx up to 15 codes.

I only suggest flying leads off the pcb as most people will want to put the thing in a nice box with big, juicy binding posts on the out side. PCB mount screw terminals cost about a buck a terminal.

Angelo, your size spec is a little ... vague. Is this a 6 foot culvert pipe, or 15mm conduit? I can go very small, but construction becomes harder. 0402 size components are about as big as a grain of sand, they can be hand assembled (I've done it) but if you sneeze its all over! I think I could get this thing into a matchbox fairly readily, on a single board.

What sort of telco work, Nightstalker? (sorry thats probably way off topic)

[zeocrash]

Sound's cool. i was wondering about the anti tamper devices though. I used to be a cadet, and during my career as a cadet we had a lecture from major somebody of the RAF bomb disposal unit. Apparently small bombs are no longer difused by "cutting the green wire" rather a device similar to a shotgun is placed next to it and fires water through it at hich speed, ripping the bomb apart. this would negate the effectiveness of anti tamper devices. I think anti tamper devices would just make the bomb more dangerous to the user. If you want to be sure that the bomb does not get taken complete, you could put the anti tamper devices in (tilt switches etc). but not connect them to the circuit, this would make the bomb apper like it requires the water blast treatment when the bomb disposal team do an x ray of it. meaning that they destroy most of the bomb, should all other self distruct devices fail to work.
by the way put my name down for one of these

[NightStalker]

I'd be assuming that you're biggest threat of discovery would be from a dog-walker. The anti-handling would take care of that problem. Not blowing 'em up, but burning up the control box so they can't take it to the cops.

Telco work being work for a telecommunications company (a Bell) or work with phone equipment like the wiring boxes that service a neighborhood, phones and NIDs, and all that.

[Tuatara]

No, I've not worked with that sort of co. I've done the odd modem though. Whats your idea?

Additional security against casual removal could be as simple as big steel spike to hold the receiver, at least the thing wouldn't convert to molten slag in someones hand.

[Anthony]

This isn't a dig, but if the equipment did come with antihandling boobytraps, I would probably disable them. IMO the risk of personal injury or accidental equipment loss outweighs the advantages.

If a dog walker can stumble across your reciever when you've retreated to fire it, then you've failed to secure the perimeter of your blasting area. Or at least failed to make sufficient checks before starting the firing procedure.

[NightStalker]

Something that could be hooked up to a phone line to either re-route calls (either all calls, or only those being made to certain numbers) to another number, without the person calling knowing that their call was being re-routed. Or, play a pre-recorded message of your choosing.

For instance, someone calls 999 and gets re-routed to a number with a recording telling them "all lines are busy, try again later." :p

I've seen something like this in a catalog for about $50, but it won't block 999, nor do anything more than play the one message it's programmed with.

Ideally, the device could be attached to a switch box that controls the phones for a small area, allowing you to lock out any calls for police help in that area, without stopping calls to any other number. Just the thing to have while blasting, so you've got time to get your stuff packed up and gone, before anyone figures out the reason why they can't call 999 is because the phones have been buggered. :)

As for the dog walkers...yes, I'd do a check first, but you have to plan for failure, eh? <img border="0" title="" alt="[Wink]" src="wink.gif" /> At least if the AH is built-in, you have the option to disable them...better to have it and not need it, than to need it and not have it.

[Skean Dhu]

few suggestions

personally i'd rather spend the extra $2 on the screw terminals on the reciever just for reliability's sake
also, I propose few frilly options, firing circut continuity check (ie an LED or 2), signal confirmation for when your non-LOS or going through a hill, a 'saftey' switch on the transmitter to lower risk of premature signal transmission, and finally on the reciever have it close a circut to a provided powersource so the user can decide how many volts they want/need to use based on the device they are using.that way we don't have to always use 6v or 9v

i would be happy to make a donation to the development of the gate opener.

<small>[ March 07, 2003, 04:47 PM: Message edited by: Skean Dhu ]</small>

[Jhonbus]

All this talk of safety override options gets me thinking about perhaps having the simpler (and safer) solution of having to hold the transmit button down for a time (perhaps 5 seconds) to detonate the charge. This would avoid inadvertent detonation, and allow the detonation to be aborted simply by releasing the button. This idea has fail-safe written all over it.
Also I think the utility to have multiple charges set off from one signal, with a programmable delay in between would be useful.

[Tuatara]

Jhonbus, having just a simple '5 second press' requirement on the trigger button is not safe at all, what happens if something presses on the button while you are returning to your safe zone? This can, and will, happen!! It is far better to have a separate key that can lock off the transmitter, and be removed while the transmitter is not actually in use. The '5-second' delay approach is still very useful from the 'instant abort' perspective - I'd thought of adding something like that myself, but I still think you need a physical lock on the transmitter.

Nightstalker, I suspect you would have great trouble diverting 999 calls, as I believe the phone exchange handles these differently, making interception impossible without actually putting something into the exchange itself - mission impossible I'd say. I think most of the call diverters are meant to sit on the end of a subscribers line, and send divert messages back to the exchange - don't ask me how, I don't know. You may be able to mount something equivalent to a DNS attack by flooding the exchange with calls, but I don't like your chances.

[gecko]

hello all,
I was just thinking that the safety switches that some people want fitted into the transmitter would be more expensive. As the transmitter should be reusable.

Now screw on terminals would mean guaranteed connection but the option should be there to not have them installed.

Now if the plan for the receiver was really easy to customise, then that would mean that the person making the receiver could choose whether or not to have screw on terminals, or extra safety devices.

But like they say, you've got to spend money to make money.

So it really depends on what your using this for. For those of us that are testing our newest concoction out in the field, it would be alright for the receiver to be a little bit more expensive, as we can install longer wires so we can bury the receiver a couple of meters away so the receiver would live through the test.

Yet those of us that will connect the receiver to a charge that is to allow us entry into a building then we would want the receiver to go bye-byes with the charge. So would it be possible to have the design to be easily changed to accomodate our different requirements.

So in other words, I am interested.

[Tuatara]

I've just found that Maxim do a couple of ISM band chips (868MHz Europe, 900MHz US) witha transmit power of 200mW. Thats enough for a range of 1 mile. Ideal for the larger experiments ...

[Anthony]

Excellent!

Personally, I don't like the idea of a fire button that you must hold for ~ 5 seconds. The suspense would kill me, and it makes timing a detonation (for entertainment, or with a thunder clap etc) difficult.

[Tuatara]

So, lets add 'programmable firing delay' to the wish list :) . Should be easy enough to do.

[Energy84]

So what's the estimated cost of this thing so far? Seems like it ain't gonna be cheap by a long shot! <img border="0" title="" alt="[Frown]" src="frown.gif" />

[spydamonkee]

Energy try actually reading that thread and you will come across the estimated costs in nz dollars :D

As a fellow Kiwi I Would be very interested in purchasing one of your setups as the next dream looks like a very large CANFO charge 100kg's or so :D
could have used this thing when i detonated my 10kg CANFO that way i wouldnt have got covered in sand :(..

i would mainly want the device to be Safe, Simple & Reliable with the option of charge delays as mentioned.

[0EZ0]

Well I have to say this all sounds pretty damn interesting!
Remote ignition would be somewhat more professional than the old 'light and run' method.

I've had no personal experience with any remote type electrical firing sytem. But it seems that it would be alot more convenient than any mechanical firing system for experimental use.
Hell, I could see use for this in a new years pyro display. Such a unit would be quite versatile.

I've had some recent experience using electrical firing for pyro pieces, and instantaneous ignition is quite a plus. You can almost throw away that old feeling of imminent disaster if a problem arises. Although you would certainly have to have a arming key on the transmitter to avoid new issues that come along with an electrical firing approach.

All this looks very promising. I'll keep an eye open for any progress :) .

<small>[ March 17, 2003, 06:08 AM: Message edited by: 0EZ0 ]</small>

[jarrod]

Energy84 “cost would be about NZ$10 for a transmitter with 4 buttons, and about NZ$15 for the receiver”

Yes this is interesting and I am most likely to purchase one (for my garage of corse <img border="0" title="" alt="[Wink]" src="wink.gif" /> ) Earlier you referred to size, “I think I could get this thing into a matchbox fairly readily, on a single board” with 0402 sized parts. Were you referring to the transmitter or the receiver? If the transmitter could be made to fit into a matchbox using a ballpoint pen or small rod of some description to operate the buttons, this would make concealment easy. If you were referring to the receiver is it possible to get the transmitter this size, if not what would be the smallest size?
And yes I understand the annoyance in working with very small objects, so a larger fee for assembling shall not be a problem :p

[BoB-]

Okay, first off, the self destruct mechanism is no good, what if a dog walker or even a ranger is walking by, you manage to hide the transmitter, and tell him your just off for a walk. Seconds later a massive cloud of smoke erupts beside you and some brush ignites. Even if they dont find the main charge you'd still be charged with arson.

And what if you just plain screw up? Sure you built it but we're all only human, and the more complex the task, the more we're prone to fail. Simple as that.

If you eliminate the James Bond bullshit, you could cut the price in half, enabling you ditch it if you make a mistake and draw heat. You can also eliminate many electrical safetys by improving procedure. The area should be scouted to ensure its not patroled, and the charge should be buried to help eliminate shrapnel.

All the safetys could be replaced by a toggle and 2 9v battery connections;

<img src="http://www.networkcable.com/images/batthldrs_snaps/sbatsnap_hard.jpg" alt=" - " />

The power to the toggle is routed through the battery connections, when connecting the charge to the receiver, these battery connections are seperated, then when ready to fire, the connections are snapped together, and the toggle flipped, then the firing switch pressed. Safe, reliable, and costs about $2 American dollars.

Damnt, I gotta go work. So just remember this; Is it flashy and professional? Or reliable and cheap? No more James Bond stuff.

[Ezekiel Kane]

Very true, BoB-, cut down on as many expenses as possible without compromising safety - why not? We're not 00 agents, and are secure enough that we don't need the flashy setup just to blow something up.

[zeocrash]

i think one problem here is that the recievers cost more than the transmitters, this may not seem like a problem, but consider that the reciever is the part of the system that is most likely to get destroyed. i would suggest that most features be part of the transmitters, and the recievers only have what they really need in them, ignitor circuit, and the special code deely chip. all other features go in the handset.

[Tuatara]

Let me address the issue of 'James Bond' type features. This will all be up to the user!! What I'm intending to design will be a couple of PCBs, one a transmitter with a bunch of connections for buttons, one a reciever with a bunch of connections to drive relays, or whatever your please. If you want to forgo all the fancy shit, like keyswitches, delays, self-destruct etc etc, then thats up to you :D . If you like that sort of stuff, then the facility will be there to add those things <img border="0" title="" alt="[Wink]" src="wink.gif" /> .

I will try to make the design as generic and low cost as possible, without compromising the reliablitiy of the radio link - which to my mind is the most essential element.

With programability in mind, I'm thinking a simple RS232 interface to your PC, with some Visual Basic code to program all the options. The interface on the radio gear will simply be a couple of pins connected to the mircocontroller - very cheap and simple. This is real easy to do, in fact it is exactly what I'm doing with the vehicle alarm I'm working on.

Jarrod, I think maybe a couple of different board designs might be in order so folks can pick the cost / size / difficulty ratio they prefer. If you want to conceal your transmitter I'd suggest gutting a cheap/old cellphone and using that as the case - heck, it even comes with a keypad , 900MHz antenna, and battery!

[Ezekiel Kane]

I like the idea of using a phone as the transmitter case. Very inconspicuous - if you use a DTMF chip to decode the detonation signal on the receiver, there's a bonus there as well. Simply set the receiver to accept a multiple digit detonation signal, and dial it into your transmitter. It looks just like you're making a call. I'm quite interested in what you turn up with on these PCBs.

[chemwarrior]

Tuatara, it looks like your really on to something! Features galore, put me down for the best you can make. I may never use a particular feature, but if I need it, I want to have it ready! What do you think the price range for an 'ultimate' would be? Do know that things like screw plugs are a must- I dont want to have to tear it apart to add more wire. Also, the reciever and transmitter must be easily transportable, concealable, etc.

So, can you make an 'Ultimate', and what would the cost range be? There is no limit to how much Im willing to spend (well, yeah their is, but...) but I want the best that you can design. Includin' any 007 type things you can come up with. :D (Once again, I want EVERYTHING :D )

<small>[ March 21, 2003, 07:32 PM: Message edited by: chemwarrior ]</small>

[Tuatara]

Oi! I might just give up my day job :D So we've got the likes of Bob and Ezekiel who would like a bare bones, dirt cheap version; Jarrod who would like everything really tiny; And Chemwarrior who'd like the Rolls Royce/ MI6 version !

Lets see if it really is possible to please all the people all the time!

Chemwarrior whats your idea of 'ultimate'? I think a lot of the fancy stuff like delays, sequencing, multiple receivers etc is easily handled in software, so there shouldn't be any additional cost (apart from my hair). I'm still cruising about (when I have time) looking at parts which should be cheap / available (nothing made from unobtainium!) I'm thinking of using the PIC16F84 processor - its very popular, theres lots of cheap programming gear, the MPLAB development software is free from Microchip, so those who are so inclined can easily modify my code or write their own. If this chip is too expensive in your neck of the woods let me know - I might be able to swing a quantity discount or something.

Price for the 'ultimate'? I can't see it going over US$30 each end - that would buy a LOT of hardware.

[Mr Cool]

I think I'd like a fairly simple push button --&gt; "BANG" design, but with as much protection from interference and other safety features as possible. I'll have to read this thread more thoroughly some time and make a list of features that would interest me...

Any possibility of having an EBW circuit integrated into the reciever? 2kV with 5J or so of stored energy, with the lowest inductance, lowest resistance, fastest switching mechanism possible.
In fact I'd be interested in one of those without the radio stuff, with just a lead going to a button to fire it, and some coax out the other side to the det. I'm not an expert at electronics and everything I put together seems to break itself sooner or later :(.

[chemwarrior]

Christmas is commin' early this year :D

Tuatara, I dont have time right this second to write down features of what I would like, but I'll try and e-mail you tonight with some of the specs.

Also, what do you have in mind for safety features? I heard you meantion a 'key-ignition' sercurity feature of some form?

Edit- Its not that Im trying to be vain or anything , I would just much prefer to have everything I could possibly want all together, instead of having to have adaptors or other devices. :D

<small>[ March 22, 2003, 02:13 PM: Message edited by: chemwarrior ]</small>

[Tuatara]

Mr Cool, can you point me in the direction of some info on EBW dets? I can understand the energy requirement ( 5J is fairly modest), but not the voltage requirement. Things get a lot harder / pricier once you go over 1kV. I used to desgin electric fence energisers - the biggest could pump 36J into a 30 Ohm load, peak output V was 10kV. And it did this every 1.5 seconds!

This sounds like a separate project to me.

[Anthony]

An EBW module would be good. Personally I'd prefer it as a seperate unit, it could simply sit between the main reciever output and the blasting cap. Taking the high current output from the reciever as a trigger.

[Terry Collins]

There seems to be a lot of electronic know-how around here and I don't want to start a new topic so I'll just ask: I use this garagedoor opener to safely and remotely open my garage doors :) but the transmitter has a limited range: only up to a 100 meters.
The frequency it operated on is 433,19 MHz and it's probably digitally coded (but maybe DTMF).
Now, is there a simple way to increase the range of the transmitter?
For example by using a different atenna? Longer, shorter, 1/4 wavelength ?
Or can I direct all the EM waves by using special antenna so instead of transmittig the signal in all directions, it's directed in the way you point the transmitter so this would not waste any power and would increase the range significantly.

Also maybe there is a way to copy the signal and sent it out with a stronger transmitter?

[Tuatara]

That question is not strictly on-topic for this thread, but its real easy to answer so I don't mind <img border="0" title="" alt="[Wink]" src="wink.gif" />

First off - it wont be DTMF! More likely to be On/Off keyed Manchester code.

I would stake large amounts of cash that the antenna in your remote is a 'loop' antenna, printed on the circuit board. These are notoriously poor antennas, but they have two saving virtues - they're small, and they are not much affected by hand proximity.

A better antenna will certainly increase your range, try a 1/2 wave folded dipole, as it should have an impedance of about 300 ohm. Simply sticking on a long bit of wire won't necessarily make things better. The key is impedance match - make impedance of your antenna match your transmitter, otherwise all that yummy RF gets bounced straight back into your transmitter, and ends up as heat. You can get directionality using a Yagi antenna - more elements = more forward gain, more directivity.

You can add an RF amplifier to the output of your transmitter, but I'd build a better antenna first - you will get more bang for your buck.

Now go surf the web for antenna design tutorials! :D

[Haggis]

If any of you have an established blasting zone, wouldn't it be simple to rig the area with a proximity sensor? I have a relative that designed an electric gate to open whenever somebody or something tripped what he called a 'loop detector'. This way, when something trips the loop, a relay in the reciever is flipped over so the final detonation cannot be preformed. When this happens, a signal could be transmitted back to the transmitter signaling that, yes, something is in the area. If this is not line of site, I can see where this can be helpful. I was thinking a 50'x50' area with the wire buried 3-4" underground. 50 feet should be enough for all but the largest blasts to protect both the clueless people who wander close, and the wire from being broken or uprooted.

[kryfo]

I'm of a mind with Chemwarrior, I'm definitely interested, and would want the most possible features. Heck, I'd rather spend more money once, and have any feature I could possibly ever use, rather than spend a bit now, then find out I need another feature, and spend some more, and so on and so forth... So definitely count me in on the super duper 007 model!

[jarrod]

Tuatara - just enquiring to what stage of development/testing you are at. By no means Im I asking you speed up you design, just trying to foresee an approximate production month/year.

Slow and Steady wins the race <img border="0" title="" alt="[Wink]" src="wink.gif" />

[Tuatara]

Sadly (or not depending on your point of view)I'm a very busy boy just now. Got a big deadline to meet or my current project gets the plug pulled - urgh! hate working nights and weekends :mad: .

On the bright side it looks as though the next project will be using the ISM band (868MHz) so I think I may adapt that to our purposes.
I know its been a while since I (foolishly?) volunteered to do this, hopefully I'll get into it in the next few months.

Please be patient, I promise I'll get there in plenty of time for Christmas <img border="0" title="" alt="[Wink]" src="wink.gif" />

[chemwarrior]

Tuatara, I e-maild you recently with some of the specs? Did you not get my e-mail or something? If so, Ill re-write everything and re-mail it to you.

[Tuatara]

No, nothing turned up in my mail. How long ago? Could have been anti-spammed?

[nbk2000]

MwuahahaHAHAHAA!

Fear my elite skillz! I have made an R/C circuit that uses <$10 of parts (per unit) from radio-shack, and will work with any walkie-talkie you can plug it into!

No vaporware from me!

:D

I'll post pictures in the next day or so. I'll even attempt to draw a schematic, but I don't promise anything, since I can't even solder. :p

In the meantime, you'll need to buy a 741 op-amp IC, a 2N2222 diode, a 10K variable resistor, 470 resistor (yellow, violet, brown), 4.7K resistor (yellow, violet, red), plus a relay, 9v battery snap, and a mono phono plug to fit whatever you're going to be plugging it into.

I've been testing it using an FRS radio. Range is limited to however far you can get your radio to receive your transmission. My line of sight is limited to two blocks (hills), so I couldn't test further than that with my current setup since my "detonator" is a bright LED, but it works at least that far.

No DTMF tone coding, or other fancy shit, but it's easy to throw together in a pinch and you can add a time delay to prevent "scoring an own goal". ;)

Next objective is to add a sensor that'll plug into the VOX mic jack to either let you know when the target is within range, let you listen in, or even just for remote counting.

Not counting the battery, or relay, the circuit itelf would fit on a thumbnail. :)

Oh, and once I tell you how I figured out this circuit, you'll REALLY hate me, because it's been sitting right under our noses for the last couple of years! :eek:

[pyr0man1c]

if you could make a radio-controlled blasting machine that looked and worked like a wrist watch and had these features:

*programmable key cryptographic identification
* the possibility to attach a larger & better antenna and an amplifier

i would certainly be willing to pay at least a thousand dollars for it. the worst problem then would be the payment, i won't send a thousand dollars to the other side of the world without knowing i'm getting what i'm paying for. i guess you'd have to trust me.

i was examining the possibilities to use a laptop computer to control the initiation of different pyrotechnic charges about 8 months ago, but i've been doing military service since then so maybe i'd better dig up those old C programs i wrote... i remember i had a hard time, i'm really not much of a programmer. heh ;)

[Tuatara]

Fabulous! Now that NBK has that end of the market sewn up I can focus on the 007 version:D

Oh, and don't be too hard on vapourware... I worked for a company that scored multimillion dollar military contracts with vapourware (and the odd bit of painted wood). It was bloody hard on us engineers though ("you have 3 months to design, program, test and manufacture this piece of MIL-SPEC equipment")

Yeah, that payment thingy is a tough one. I'd thought the Pay-Pal service might be handy. Oh, and I doubt anyone need spend $1000 (donations gratefully accepted of course!)

[nbk2000]

In the "Sensors_for_Bombs" PDF, upped by me, on page 22 (page 25 of the book) is the circuit I used. It was handily provided by Radio-Shack, but it took me a while to figure out an more practical purpose for it. :)

I still have to tweak it to get it to work with a relay, but it's going...unless you'd like to help out Tuatara. ;)

[Tuatara]

Gladly will I help out. I'm but a short email away ...
(no FTP you see :( )

[Tuatara]

Thanks for the mail NBK. Sorry you've so many problems with hate mail:rolleyes:

Heres how you drive a relay with your circuit -

Replace R3 with the relay
Connect a diode (1n4001 type) across the relay coil, with cathode to +9V - this just protects the transistor when the relay turns off
Replace the LED with a 1n4001 diode - needed because the 741 output only goes down to 1V

I'd not recommend an SCR - too prone to false triggering e.g. dV/dT triggering when the circuit powers up, and the tiniest spike from your radio will also be able to turn it on.
Relays are actually very reliable and have some nice features for this application.
- they are (comparatively) slow, so will tend to filter out any noise spikes from your radio
- no false triggering
- you can biff a lot of excess current through relay contacts without the thing turning into a fragmentaion grenade.

Your 9V batt should be capable of delivering the 100mA or so to drive the relay. The 741 output cannot deliver this kind of current which may be why your earlier attempt failed.

Be very, very careful using the squelch on your radio, as a trigger! All kinds of RF crap can unsquelch a radio receiver - car ignitions, other radios, lightening, electric fences, bad luck ...

I would have added a pretty pic of the relay circuit but I couldn't figure out how (and me with a degree in electronics
:o )

[nbk2000]

Here's the schematic for the radio controlled light circuit. ;)

http://nbk2000.freeyellow.com/RC_schematic.gif

You adjust the variable resistor till the light goes out. Then press the button on the other radio to transmit. Adjust till the light just barely lights up, then up it just a tad. This prevents it from flickering from static since you have to be transmitting for it to activate. If you turn it down from when it's lit when NOT receiving, it'll drift and activate itself after a while. That'd be a bad thing.

There IS current flowing through the LED at all times, so you'll need to adjust the resistors so that it's below the threshold needed to "light up" your "subject" matter. :D

Or you could use an opto-isolator relay IC to replace the LED to act as a relay for an external circuit.

I don't use only the squealch, but also the CTCSS side-band channels to decrease the likelyhood of false triggering. I've had the circuit running for the last couple of hours and haven't seen it blink once, except when I transmit using the CTCSS band on my transmitter.

Also, the circuit has a quasi-boobytrap feature of activating if the phono-plug is removed from the receiver, or the radio turned off. :) If the power supply was sealed into the circuit, and the receiver left in plain sight, it'd be highly tempting for a non-pro to attempt disarming by simply unplugging the circuit from the radio. ;)

I assume this diode is something I could find at a Rat-Shack?

And, since I'm on a roll, I also thought about the utility of using another circuit I found on the net called "cellular helper" as a very specific means of targeting a person. See, what this circuit does is detect the ring signal from a cellphone, and triggers a vibrator to let a person know that their phone is ringing when the ringer is turned off or it's too noisy to hear it.

Well...if you know the targets cellphone #, you could plant a weapon somewhere the victim would be in the future, and simply give their phone a call when they're there. Though ANY cellphone receiving a call within a few yards would trigger the circuit, so discrimination may be a problem, unless the idea IS to target any cellular use, which could be useful in itself. Maybe to trigger a jammer that is otherwise in "stealth" mode, to prevent detection, and to conserve power.

You can up your pictures to the Forum now, using the attachment option at the bottom of your reply. Try using it, since that's what we've got it for.

[Tuatara]

Well according to the little 'Forum Rules' box on my screen
You may not post attachments so I don't know whats going on. Perhaps its a priviledge allowed to long time members?

Just because you didn't see the flash on your LED doesn't mean it didn't happen (Urgh! what a mess of negatives), which is why I think a relay is better than an SCR. The best test would be to hook the thing up to burn out a fuse wire when triggered, then leave it running for a few days.

1N4001 diodes are common as dirt - you can get them anywhere. Exact type is not that important, but these are really cheap (a few cents).
BTW on that drawing the LED has one long leg which is the anode, the short leg is the cathode and is connected to the negative battery terminal (just a clarification)

[Lurking_Shadows]

(off topic)
Tuatara for the plans of the remotes/receivers will they be accessible on the net via a web site?

(on topic)
Would it be possible to have a timer on the detonator with the possibilities of sending a signal to it and it going off at the set time so you don't have to be in the vicinity when the explosive devise goes off?

Also for buying the finished item would it be posible to get it POD?

[Tuatara]

I wouldn't call your first question 'off topic' :D : Yes, if you read the first post in this thread I plan on making the whole design available on the FTP, for free. I've no website of my own, and no plans at this stage to create one, so the FTP is where it will be.

Second question: yes , absolutely.

Third Q : POD:confused: is that the same as COD (cash on delivery) ? I don't see why not - though I believe COD does cost more.

[Lurking_Shadows]

(Off topic)
It's just pay on delivery I'd most likely get the product sent to scatterbrains (a mail place) near my place and pay for the package there. :)

(On topic)
How much extra would it cost for a timer?
Could the timer be addapted to other remote designes?

[nbk2000]

An ETA on when we might start seeing any progress on this project would be nice.

Also, COD costs the sender money, whether or not the receipient decides to actually pay for it. If they don't, you're SOL out of the money you spent to send it in the first place.

Also, I sent you my new e-mail addy, check for it.

Also, the green lines in my schematic represent connections, not length of leads, so the LED connections are correct, with no polarity value being placed on the length of the connection.

[nbk2000]

I tried the 1n4001 diodes, which Rat-Shack does carry (even if the stupid nigger there couldn't find it :mad: )...no luck.

Now what?

[Tuatara]

Oh, yes I know the schematic doesn't represent length. It was just meant to be a helpful hint to others on how to find the correct leg on the LED.

So you built what I sent you and its a DOA? Just how big is this relay you are trying to drive? > specs: coil voltage / current.

May need more drive if its a big one.

Tell me, did the guy at Rat-shack give you that slightly vacant look that salesmen have when the answer to your question is not in the glossy brochure?

I should also ask what level your electronics knowledge is - not being rude, just want to pitch my answers correctly.

[MnkyBoy]

Tell me, did the guy at Rat-shack give you that slightly vacant look that salesmen have when the answer to your question is not in the glossy brochure?

Is that the same look you get when you tell them you would like to know if they can charge your caps for you?

True aboout the LED flashing and it not being seen. At work, we are driving LED's w/ a PW of 20 uSec. Some physical mechanical motion would aleaveate fast pulses, if one is concerned about this. But coming from smaller, faster and further, the SCR works here.

BTW. where is the FTP, or does it not exist yet?

[nbk2000]

http://www.radioshack.com/images/ProductCatalog/ProductImage/275/275-005.jpg

#275-005
SPDT Relay, Mini 2A
Nominal coil voltage 7-9v
Coil resistance 500 ohm +/-10%
Nominal coil current 18ma

A 9v battery will throw it but I don't know about anything less. I know they have 5v relays. If I have too, I could use a photo-relay IC, but that's one more chip to fuck with.

My skill level, as previously stated, is rank beginner.

I e-mailed you the new schematic for review.

I doubt a nichrome wire igniter is going to "blow" in 20 microseconds at the feeble amperage a 9v batery is going to supply.

[Tuatara]

I think I see what went wrong. Response in your Inbox, NBK!

Hey, if you really could blow that nichrome in 20us you wouldn't need a primary:D
Z-pinch fusion, anyone?

[Jumala]

To NBK:
You don´t need exactly a 1N4001 Diode. Every diode between 4001 and 4007 or 1N4148 works.
If you like I can post you the plan for LM567. It is a PLL tone decoder. It reacts only to a single frequency for example 680 Hz. If you have a whistle for this frequency you can send this tone to the receiver (via walkie talkie) and the LM567 turns on.

A few posts before I told that I want to test simple audion or superregenerative receiver for use in remote control. This is done. The superregen works but it is tricky and weak. I dont know how to get better results with this peace of technik.

I found a much better chip as receiver. It is TDA 1072 or TDA 1572(with IF output)
These chips are old and cheap. TDA 1072 cost 90 cents and needs only a few external parts.
It works up to 60 MHz, single conversion, AM.

The 868 MHz ISM band chips from Micrel are ways better but also more expensive and more complicated. Even educated people will have big problems to solder a SMD chip to the board only with standart equipment.

To make the story short, I will build a TDA 1072 receiver with tone decoder and if it works I´ll post here again.

[Tuatara]

Can you still get those ?! Your 60MHz antenna will be interesting (read 'BIG').

Actually the Micrel quik-radio stuff is very simple - just a crystal to set the frequency.

Soldering SOIC is a doddle. I've done 0402 parts, by hand, with nothing more than a loupe on my glasses.

I'd have thought your superegen would work well - mine do. I get 60m with scrap of wire for the recieve antenna and a crappy little loop antenna on the transmitter. Thats at 305MHz. I'm sure I could 200m witha 1/2 wave dipole each end - but it wont fit into a car alarm remote:D

[Jumala]

Yes, the antenna is a monster compared to the loops but also simple. A 1m copper wire works as antenna. It isn´t matched but o.k. for remote control. With a walkie talkie as transmitter it should work over a few 100m or more.

To solder SMD is no problem. I use a small solder tip but SOIC is out of area for me. I´ve seen a nice hot air solder station, good for this job, for somewhat about 1000 bucks. In the moment I like the bucks more than the solder station.

The superregen I build works too. I can receive my dip meter (It has a variable oscillator) and sometimes a CB station. I have build it for 27 MHz.

I´ll mail you two plans. The kitchin receiver is what I tryed. The other PDF is in german language but you can see the plan.

[FrankRizzo]

*BUMP*

any new developments??

[Tuatara]

I haven't forgotten this little project, I've simply had to stick it on the back burner for awhile. I've some time coming up soon so I'll try to scratch something together, just as a starter.

[jeffchem2000]

A friend of mine has a remote controlled door bell for some reason! we tested how far away the door bell would still work and depending on the atmosheric conditions we go between 75 and 100 pases. I don't know where he got this door bell but keep your eyes peeled because I think it was quite cheap. It runs off a few AA batteries at each and it would be really easy to convert for "experiments":)

[Chemical_burn]

jeffchem2000

if you have not noticed doorbells have already been discussed in other threads.

besides this thread is about constructing a reliable remote detinator not modifying(sp?) another to work if you want that it has been discussed before.

[parmin]

For those that have urgent needs:p
here in the Land of OZ, you could buy the LONG RANGE (1.8km) 433 Mhz remote control "garage opener" from Oatley electreonics for about AUD$22 TX and $32 RX kits (K190). Bout matchbox size. Assembly of the kit is required tho, not hard coz the TX and RX board is pre-assembled, only the coding section need to be soldered together. :(

For those who dream about 007 devices,:D the TX assembly from them is about 20mm x 8mm, err bout half the size of your mobile phone GSM chip. You should add some coding device, example PIC12c508 microprocessor for safety. The whole assembly including battery could be fitted inside a container the size of N size battery (say, a biro pen tip?)

The RX section, 44mm x 15mm could fit in an AA size container,:rolleyes: duh... including say, 50 grams of nitrated goody, decoder, battery & caps, err in a common texta ...

Hmm, if someone could provide diagrams, pictures and a step by step report of these things, in PDF, where whould she deliver this document to?:confused:

[Tuatara]

Oatley will mail order world wide too, I've bought stuff from them before.

FYI the radios I'm using in the car alarm I'm designing: transmitter is 10mm x 8mm, reciever is 10mm x 20mm. The tricky bit with your biro pen transmitter is that the antenna needs to be quite a bit bigger than a pen, at 433MHz, if you want the range. Thats why I'm thinking ISM band, around 868MHz, built into something that looks like a car alarm remote, using Microchip Keeloq encryption devices (64bit non-linear, rolling code encryption, all in an 8 pin SOIC).

"she" Parmin? Could we really have another female member?:cool:

[nbk2000]

She could e-mail it to forumscan@yahoo.com, I'll review it, and if it's good upload it somewhere for the rest of the Forum to download. :)

Couldn't the antenna for the pen tx be a length of wire on a spring-loaded retracting spool? Pull of the pen cap to extend the antenna.

[Bert]

I know this wouldn't be as much fun as making your own-

Miniature 2 channel firing system with 300 ft. range for about $150.00 (http://www.radio-match.com/)

But you could be using it next week...

[parmin]

On the subject of antenna..

The idea is DIPOLE system.. :o see, the body of the pen is made of Aluminum and is to be the ground plane part of the dipole, and a telescopic style antenna is fitted (with insulation of course) inside with the tip poking out one end of the pen. :rolleyes:

Now by calculation, 434 Mhz system will need about 6.5 inches antenna for quarter wave. A standard biro pen is about 6 inches. By right we are missing .5 inches on the ground plane side, however, when we grab the pen (to push the button) the hand/body/sexy legs;) would be part of the grounding circuit. Not as good ground as aluminum bar of course, but should be more than ample to made up the missing half inch :p .

So what do we get? a dipole system when we extend the antenna to 6.5 inches length. A mark or simple modification can be done on the antenna to make sure we get the right length.


To Tuatara, the someone may be a she... (o)(o) who knows? I said if... :D ***This line is added 5 minutes after the original post - How would one purchase keeloq devices in small quantity? So far I have used standard PIC12C508/9 for my toys, of course the 16F628 too :) ***

Sometime next week, NBK may find between emails of penis elongation and breast enlargement :D, an instalment of enlightening article from somegirl ;)

[Tuatara]

There's no need to be 1/2 " short on the antenna. I remember seeing somewhere a pen/ lecture pointer combo, where the pointer end telescoped out to about 2' . The thickness of the pointer section should help increase the bandwidth of the antenna, and mitigate the sensitivity of dipoles to 'hand-effect' de-tuning. I wouldn't count on max range, but a good idea, now that I see what you're describing.

Just seen your edit : Keeloq can be bought through Farnell (http://international2.farnell.com/) , I think Digikey (http://www.digikey.com) have them. You can also buy direct from Microchip (http://www.microchip.com)

If you've got one of Microchips PIC programming tools, then you can probably program Keeloq too, otherwise you'll have to do what I did and build your own. Check Microchips App notes for a standalone programmer (AN217)

[parmin]

Correct me if I am wrong,

a keeloq would automatically output a 64 bits code when activated right? ( i never use one before ) :confused:

if so, a keelog output coupled with the TX unit would work stright away without any complex asm work.. true?

true the body would de tune the active part of the dipole, however wouldn't the ground part of the dipole be enhanced?:rolleyes:


The advertised range of the tx is about 1.8km with 12 volt , we only aim for say 500 m or umm about a quarter of the max.. should be good enuf hey? :p

[nbk2000]

I have no need for either penis elongation ;) nor breast enlargement :eek:, though I'd be happy to see anything interesting that you may have to show me. :D

I meant the circuits, of course. :p

Though I've always been spam-free with my e-mails. I have a hard time sympathizing with all the people I hear complaining about spam. Don't publicly post your e-mail on the internet, don't give it to dodgy sites (read porn) or enter on-line contests, and certainly don't put it on any kind of "warranty" card you may get with a purchased item.

Don't do any of these things and you too will be spam free. :)

If you can get these circuits very tiny, and have at least a hundred foot range through walls, than that'd have all sorts of applications besides just blowing things up.

And, of course, it has to be reasonably cheap (under $50), use available parts, and not require an engineer to assemble.

[Tuatara]

Parmin, you may find this document (http://www.rfm.com/corp/appdata/antenna.pdf) useful. Its a basic description of a wide variety of antennas that can be used for this sort of application -whips, chips, loops, helixs, slots, stubs, patches etc

A 1/4 wave whip only works because the 'ground' plane creates an image of the whip so the whole thing looks electrically like a 1/2 wave dipole. Change the tuning on the whip and the antenna performance changes, no matter how good the ground plane is. (if you're ugly, the best mirror in the world wont change your face). The sensitivity of the whip is due to the fact that the end of the whip is a very high impedance point, so the antenna is easily detuned by the small amount of capacitive loading to the surrounding environment. This in itself is not the problem, it is changes in that environment (how far your arm is from your body) that cause trouble.

To answer your questions,

Yes, the Keeloq encoder is a 'Button in / data out' device. All it needs is to be programmed with an encryption key that matches the decoder at the other end. My car alarm remote is just three buttons, keeloq chip and SAW transmitter - easy (and small). There is also a simple decoder chip available too - data in, 'button' out. Go to Microchips website - there's lots of application notes to help you.

Banking on 1/4 max range should work, though I'd test it first ;)

[parmin]

Tuatara, I thank you for your input re. antenna. Yes I understand the point you are making. Lets not worry too much on that matter for this moment. Because although we are not making maximum transmission signal, we could get quite far signal delivery (better than standard car alarm type) thus giving a slightly higher margin of safety to gageteers in the forum. Bear in mind, the point of this design is not for optimal range but instead it is for miniature size.:)

Now, I have been busily making this device and trying to put my self in the shoe of a non-engineer. I am stumped on a few. problem. :confused:

Quoted from nbk2000

"If you can get these circuits very tiny, and have at least a hundred foot range through walls, than that'd have all sorts of applications besides just blowing things up.

And, of course, it has to be reasonably cheap (under $50), use available parts, and not require an engineer to assemble."

End Quote.

Gosh, two paragraphs that made me have sleepless nights.

First "at least a hundred foot range through walls" . Ok.. what wall? Brick? timber? fibro? corrugated steel? aluminum? Concrete? or all of the above? How thick is the wall? does the wall have steel reinforcement mesh on it? On my assumption of standard brick walls, within one hunderd foot there would be less than 5 layers walls. (viz. four rooms of 20 foot wide) If thats the case, chance is that there would be no problem for the device to work reliably. Of course we are not blowing things up.. why would we? :D


Second, Cheap - under $50. If you do it your self, using the materials purchased from the place I mentioned, plus some of stuff you salvage around your home, yeah it can be done. In fact if I am to quote of purchases of say 1000 units, it may be well below $20 mark.

Third, use available parts. Yeah.. the parts is available, you can buy it easy and from lots of suppliers. BUT, some of the parts need to be programmed (be it a keeloq, PIC, AVR etc) to give you the security of the rolling 64 bits encoding.
You dont have to be an engineer to assemble the circuit, but , you have to have access to a microprocessor programmer to be able to do this.

+++That reminds me. Tuatara, I have been poring over the keeloq device. Aparently they only have 32 bits rolling code. You need to program another 32 bits serial number into it to make the 64 bits encoding for it. For the trouble, I reckond using a standard $2 PIC12C509, with your PGP key as the serial number would cut a lot of problems in programming, serial numbering etc. Plus they are much more readily avalable and cheaper too :) Hmm, may be a PICaXe unit can do it.+++

Now, nbk2000, you tell me, would programming a PIC be too hard for average rogue scientist? If it is not, then you are getting a remote device as secure as your PGP encription. If it is, the alternative would be back to the ole simple car remote encoding chips :p

[Tuatara]

If you really want to program your own encryption, I believe 'Twofish', DES, AES and RSA are all in the public domain now. Me - I want easy! Encryption built into Keeloq, Decryption code ripped straight out of a Microchip app note:D

My radio parts cost me $0.60 for the transmitter, $2.50 for the receiver (US$). Not exactly 'off-the-shelf' though.

Through the wall range - info I have indicates attentuation by walls tends to be proportional to the third or fourth power of the distance (normal 'free-space' is 2nd power of distance for 'far-field')

I'm not sure I believe the 1.8km claims for those Oatley radios - the tx is only 18dBm max and the rx is -115dBm sensitivity (I think theres a typo on the main page - the data sheet says -115dBm)
1.8km would be a theoretical figure with no channel noise, and perfect antennae, I suspect.

[nbk2000]

Obviously, if someone is a member here, they have access to a PC, so we'll assume they can fiddle with PIC's to their hearts content.

However, no need to hopelessly complicate things by custom programming PGP/3DES/AES/etc into the circuit when a simple rolling car remote encryption scheme will work. After all , we're not worried about ECHELON recording our test firings and trying to hack the key to our remote for nefarious purposes. ;)

We simply want to prevent accidential detonation from any nearby radio transmitters.

As for walls, that depends. Sheetrock and 2x4's are transparent to RF for the most part. But I wouldn't be setting off shit in a house anyways. I'm thinking more along the lines of commercial construction of steel beams and such. Not solid steel with grounded mesh, but the sort of thing you'd find in commercial/industrial construction, as well as governmental buildings.

If that had to be an upgraded version, that'd be doable, but for now lets stick with the safe remote for testing out in the boonies where you only have to worry about trees and shrubs.

I saw a LANL article where they had programmed PGP into a chip for integration into circuits. If it would be possible to program it into a chip that could be screwed onto walkie-talkies (between the antenna and the transmitter?), than that'd be the shit! You could take it with you, use it on different equipment (prevent RF fingerprinting), and (hopefully) be able to change key groups as needed by the mission.

[parmin]

yes, the range claimed by oatley would be the theoretical range under perfect condition, usual advertising jargon. But again I am not really aiming for the impossible range.

For coding, AAARRRGGGHHH!!!! :mad:
I think I did not put it in word good enough. My idea about PGP key is that the key is unique to individual who use them, thus it is an automatic "rolling code". The way I will use it is, for example if I am nbk2000, I would send a serial code of say "D578 AE65" to activate my receiver. Not hard thing to do, and very simple to program in the PIC12c509. Or if I want to I could even use something like "THINGS GOES KABOOM" or "BUSH IS AN IDIOT" as the serial keycode. Thus if you want to use channel one you send "BUSH IS AN IDIOT 1" and for #2, "BUSH IS AN IDIOT 2" ETC.

The program flow would be to parse X amount of variable and check if the variable match the one in memory byte by byte. If it match, activate result. if not, go back to wait. Simple. No rolling code required. It is a standard password type security. And with 12C509 we could use up to say 30 byte character..:rolleyes: thats 240 BITS of data password. How much easier could it be???? :p

All it did is only to ensure that there is no one else using the same code, thus may activate my receiver without my consent. I do not mean to custom programming for PGP, I mean to use some phrase of data that no one else may chance to use.:o

Plus, if I could purchase everything and cheap I need from one supplier, it would be a bonus. The beauty of using 12C508/9 is that both receiver and transmitter would use the same chip, only programmed differently. So all you have to do is purchase a few of the same chip to make any combination of TX or RX devices. :D

As for something to put in to a walkie-talkie to activate only with a certain code, simply buy a walkie with SELLCAL feature in them. They would be MUTED until a matching SELCALL code is received.
Simple technology. If you look for say a pair of Philips PRM80 units, you can program the selcall to your heart content and activate your remote device up to 40 km away coz they have 30watts TX power. They are BIG though.. *sigh*. else something like a walkie with selcall like uhmm.. a GME TX6200 can do it for 5 km range :D

[Cricket]

If I was to buy some remote umm openers, I would think these to be useful.

1. Good range, the farther and more penetrative the better. I would prefer something like 100' minium in open country and for the 4th of July stuff, a mile or so would be wonderful.

2. You all probably mentioned this in your technical stuff that I am far from understanding, but it would be good to make the reciever activate only when it recieves a primary signal, and then a confirmation signal to reduce the chance of a fatal accidental door opening. And if the confirmation signal isn't received within the time the transmitter is programmed to send it, then it would restart it back to as if it hadn't received the primary signal. Again, you all know more than me on this one so I bet it has already been discussed.

3. Some sort of electronics made available that you could set up to receive and resend the signal(s) so it would increase the range indefinatly if needed.

4. For the transmitter to have the ability to open different doors at different times via different buttons or combination of buttons. Not too necessary for the average door opener, but could definatly be useful at the right time. But this may increase the cost a lot because of the transmitter having to transmit more than one frequency. Unless it is possible to program the transmitter to transmit the the same frequency, but not constantly, maybe like morse code. And then to have each reciever to be activated only by a certain code.

Thats all I can think of now that I would want the most. I would pay very good money for 2 transmitters and 50 recievers and maybe a few #3's for real big doors ;). Good luck with it's R&D.

[parmin]

nbk2000,

somegirl may have already send an installment of enlightening article to you. Check it out.;)

What should I do with my proto??:confused: sell? how much?

[havic]

I don't know much about the radio side of remote detonation unfortunately, however one item that I have used in other projects that could serve as a good trigger on the output would be the ignitor from one of those electric gas lighters.
Generally about $5AUS for the lighter, but easily connected into any form of receiver circuit.

Alternatively if that doesn't have enough kick in it and providing that you have a good power source on the receiving end, an automotive ignition coil works wonders :D
These can range from between $10 - $35 (ballpark figure) from pretty much any auto store :D

If you've ever gotten a kick from a mower that had an electrical fault, you'll know what I mean :o

[Tuatara]

Most of those gas lighters have piss all energy in the spark and can barely manage to light gas, let alone anything solid. Ignition coils are better, but not by much. Sure they hurt, but do you see any damage to your skin?

Now the 36 Joule electric fence energiser I designed a couple of years back (for an Agri-tech company), that might work. It would merrily blow the guts out of a 5W resistor. Nearly blew the guts out of me, when I touched something I shouldn't on the prototype. Fuck that was painful. Had holes in the fingers of both hands, and couldn't stop shaking for about 2 hours. Some lessons just have to be learned the hard way :o

[DBSP]

While on the OT subject of discharging caps. Just got reminded about the time i accidentally discharges a fully charged 6J photo cap into my fingers while building my blastingbox. That hurt and my arms where shaking for about 15 minutes. Wouldn't like getting stunned by a 36J cap.:eek:

Like you just said, some things have to be learned the har way...

[rdxhmx]

a usefull device for making a remote controle detonating transmitter-recieverunit can be made
from transmittermodules from conrad electronics ,www.conrad.com for example handtransmitter 192481-60, 3 channel recievermodule 192635-60 and relaymodule 115029-60,115045 and
and recieverantenna 115142-60 (plus connector UG 1094 109819-60 and coaxcable RG 174 109827-60) total cost in euro's 161.05 ex V.A.T transmittingfrequence 433.92 MHz reachingdistance minimum 100 meter maximum 1000 meter.
an other way is using an SRD module on 868.95 MHz for example transmitter 190088-60 or 190355-60,reciever 190280-60,190268-60 or 190064-60 and reciverantenna 190368-60
this makes it a lot more cheaper,easier and relyable.

[spydamonkee]

If i could get an update on the progress of this project that would be great as i look forward to purchasing one of these as the garage door remote broke again dag nabbit ;)

Also Tuatara are you NI'er or SI'er?

[Tuatara]

NI. Area code 09. I'll get on to it soon. Still finishing the car alarm. Will springboard off the alarm stuff to do the remote, so it should be pretty easy.

[spydamonkee]

That would be great, In return I can E-mail you a legal & local source for 15' roll's of Waterproof Cannon Fuse that only costs 25$ (saw your post in homemade fuze's :D)

SI, 03, chux@hush.com

E-mail me your email address if your interested.

[ak70g2]

guys, all topics is ok, but where i find some drawings? i am from romania, one of "wild east" countries.... and i know nothing about electronics! where i find some simple designs?

[flashpoint]

Tuatara, what's your email address, interested in the design and how you made the car alarm, if you don't mind talking about it...err


::EDIT:: Removed email and AIM from post.

[Tuatara]

Sorry flashpoint, I can't discuss the IP in a product that hasn't hit the market yet. That would be foolish in the extreme. I need to make money out of the car alarm, before I divulge to the world how it all works. If you want some basic ideas however you can look at the Microchip website at some of their App notes ( www.microchip.com ). You can learn all about rolling code transmitters and the like.

Christmas holidays are coming .. I plan on doing some work on the remote det then.

Here's the basic setup:

transmitter based on KEELOQ encoder (encrypted, big serial number, rolling code, readily available), can handle up to 15 buttons, or combinations of four buttons. Probably use a Micrel transmitter, maybe a Microchip one. Frequency band 900MHz ISM band - no license required.

receiver based on PIC16F84 - available, easy programming.

8 relay outputs

Visual basic program on PC to set up reciever.

For each relay you will be able to program the trigger button, trigger delay, activation time, and cancel button. If you think about it this enables an 8 event sequence of relays to be triggered by one button press, or 8 relays triggered by individual buttons, or anything in between.

[flashpoint]

Oh, tuatara, I didn't know you planned on selling the car alarm, I thought you were simply doing a DIY project...

[Tuatara]

Too much effort for a DIY :D Some things are just easier to buy in a shop

I have a couple of partners in this alarm venture, and we all want to get rich;) . And having a company gives you a certain credibility when requesting samples etc.
The remote det will be made public domain though, (well, forum domain anyway) I'm doing this design as a favor to the forum community.

[ShadowAlchemist]

This topic is very interesting as i have always dreamed of someday using remote detonation in my endeavours. The closest i have got to this design is one a good friend of mine developed himself using a kit form receiver and a GSM mobile phone.
I dont know the exact details of the circuitry/reciever, but i do know that when he dialled the designated pre-paid mobile number (on an old ericsson!), it successfully detonated a small pipebomb of FFF grade black powder.
For obvious reasons i was impressed when i heard he news, as mobile range is indefinate providing you have signal coverage. Seeing as there are quite a few folks interested in remotely detonating "roman candles" i will pick my friends brain and determine precise details of the plan.
Watch this space ;)

[Jacks Complete]

ShadowAlchemist, et al.,

that is half of the problem with this stuff. A mobile phone outputs .5watts of power, and will tend to trip even well made circuits by overwhelming them. The simple way to do what your good friend did would be to mod one of those circuits that detect incoming mobile calls. A safer way would be to run the motor wires off the vibrate out to a relay, set it to vibrate only, or ring and vibrate, then dial it.

Always turn off your phone, etc. when playing with electric blasting stuff.

Tutara,

I would love to see the plans for the electric fence!

[Tuatara]

Jack: Just out of personal interest, or do you want to build one? 'Cos if you want to build one you have to be extremely careful, or you could end up on a manslaughter charge.

[mark105]

how it goin tuatara?

wouldnt mind one of these, fuses are not goin to well for me and remote det is better option :)

[Not_Osama]

ONE MAJOR pROBLEM...and the one which has prevented me from ndertaking this project on my own is the fear of accidental detonation. You can have all the safety precautions you like, but if your receiver ges a signal...that bitch is gonna BLOW!

To prevent all your caps from detonating when you opened the garage door i would reccomend the receiver to recognise a specific signal. Say 2ms on 3ms off 5ms on 3ms off 2ms on...and so forth. This would certainly prevent almost any mishaps.

In addition to this your could transmit TWO distinct radio signals and modulate them per above.

This is the technique that the ARMY uses on their infamous Claymore mine, however they use THREE signals.
Another small problem is the cost of the receivers, they would be very difficult to reuse, as anything to close to my 200gms of HMX/RDX compound is gonna get Screwed! I would reccomend a SHEILDED base station possibly 50 ft away.

[JoeJablomy]

Not_Osama: please read the preceding posts. There has been much discussion about things like "48 bit rolling encryption," which was included in the informal 'spec' from the beginning to keep the reciever from accidentally blowing its owner up. A 48 bit code is more than enough to discriminate between the actual signals and the noise when transmitted and received properly, and is available pretty much off the shelf, whereas your homemade 2 or 3 digit, possibly non-binary*, scheme would be a pain to implement and less reliable.
As for the receivers durability:
1)They are meant to be cheap. The microcontrollers they will be built around cost a few $ each.
2)If you don't want something blown up, yes, you can place it some distance from the charge, or, even better, you can bag it and bury it, maybe with the antenna protruding away from the blast.

*It isn't necessarily bad if it's non-binary -it actually increases the possible number of signals from the 4 or 8 you would have in a binary system with 2 or 3 bits. But it seems to take a lot more work to cook up brand new schemes from analog circuitry.

Tuatara: Can you come up with a compact CD module that would easily fit in a pocket-size receiver? Also, I can't remember if anyone asked, but how about a seperate arming option like simply charging the CD? I guess that would actually be built into the CD drop in for use with the current version of your receiver.

[Zeitgeist]

Sounds cool,

when you say "Shareware", you mean releasing all the details freely?

I'm quite good with electronics, and i'd be happy to help.

If you're using an unlicenced band, remember there is heaps of traffic, but i guess inadvertant firing wouldn't be a problem using UHF Tx/Rx's based on Rolling Code technology.

using 330uF/400V's in a bank for the discharge (unless you just switch 12V or so for the outputs, CD high voltage is more flexible) is good as the components are commonly availble, you could charge the bank with a 12V CCFL inverter, only cost $10AUD, and, about half the size of a matchbox

Edit:

Purchasing the KeyLoq IC's direct from MicroChip was mentioned, what are the minimum order quantities like?

[Blackhawk]

"330uF/400V's" "12V CCFL inverter"
Yep thats the setup I am curently using for my EBW circuit, although I need a better alternative to spark gap switching. You will have to run the inverter outputs through a high voltage rectifier bridge, and when testing my setup with a multimeter it took around 1 and a half minutes to reach 350V (jumping 4-8V up every half second or so) so bear in mind that you will need to have the caps charging for some time. Also the CCFL inverter I have (IIRC it is the same with most) output 487V so I used two 400V caps in series, however if you switched the charging circuit off after less than 2 mins I doubt you would have trouble with overcharging a single cap.

[Boomer]

At that voltage, the 1-2 Watts these inverters output equal 2-4 mA! This will hardly overcharge the caps unless you leave it on for 10 minutes plus ( 2-4 mA will just compensate for the leakage).
To be 100% safe put two 200V suppressor diodes in series and parallel to the cap. Adding an LED will show you when it's ready. Two caps in parallel for only 78 Volts more give you half the capacitance and current at twice the ESR.

[Jacks Complete]

Jack: Just out of personal interest, or do you want to build one? 'Cos if you want to build one you have to be extremely careful, or you could end up on a manslaughter charge.

Sorry, must have missed this one.

I would quite like the plans for interest, but to wind up on a manslaughter charge, you must be building a Jurrasic Park type of fence! Might keep the cats out the garden, though...

I would want someone who at least seemed like he knew what he was talking about for the plans (i.e. you!) rather than some third-hand designs in Chinese.

Are there any other developments with the det.?

[flashpoint]

I also would be interested in the plans for the fence...I'm having a little problem with dogs, racoons, and cats...its pissing me off...I too am also having garden pests...

[Tuatara]

I'm really reluctant to post fence energiser circuits as there are many, many safety issues involved. It is possible to kill yourself with a 2uF cap charged to 300V. Difficult, but possible. On the other hand I survived a shock from 60uF charged to 900V. I was very lucky to get away with just burnt fingers.
The main safety criteria are
1/ ensuring at least 30kV isolation between mains power and output terminals, and
2/ ensuring the output pulse meets the C2 Line spec (Google for that one).
3/ if something breaks the energiser remains safe.

The C2 Line represents the limits for body current vs pulse duration, given a 500 Ohm human body model, an a chance for inducing fibrillation of 1:140,000.

Seriously, if you want an electric fence, go and buy one thats been through all the safety test standards - Its too easy to get it wrong and kill someone. If you're just curious as to how they work - essentially a big cap gets charged to 600V or so, then a thyristor dumps the cap into a transformer to kick the 600V up to ~8kV . Diodes across the cap stop any unused energy from reverse charging the capacitor.

[Jacks Complete]

The only problem with that is I want to make one that is more like a Taser, and that will fit into a space about that of half a broomstick, no more than 10 cm long. I have a plan.

I figured it would just be a trigger and a cap through a HV transformer, but I would like to follow a plan, rather than just make my own. I just never got round to putting the bits together. I have the caps, the diodes and the transformer(s) but no real idea about how to wire them together. I never have been that good at that kind of electronics!

[sabooky]

Did a little searching on the net and found this
http://home.infi.net/~allenk/dtmfdec.html

You could have the on button send a verfication signal back to the transmitter so you can tell if your in range (not sure if this was mentioned before)

Also thought the idea of storing the 4 digit number then firing it off with a press of the # key. Makes it more professional, but might not be to useful.

As long as the garage remote is safe enough that it doesnt close on me because the neighbers used their phone I'm happy.

[flashpoint]

what's the word on the remote det?

[Neoknite]

Also would you be able to mount the remote det into a "dummy" device like a toy RC controller so somebody that just looks at it wouldn't think it was suspicious. Make a switch that activates the transmitter and needs a sequence of buttons pushed to arm it. Just a few ideas to throw out there. Would it be possible to see your base designs so I can get a picture of what I can do with it for concealment?

[Cyclo_Knight]

I think this was suggested earlier, but would it be possible to use a REGISTERED Cell Phone as a receiver? With a slight amount of modification it could act as a switch, and could be easily protected in a well shielded base station.

I realize that you would have to pay for a plan, however all you would need would be the most bare bones plan provided, and the phone is free. You could then be in Taiwan when you set it off! Of course you would have a local safety in case someone accidentally dialed the number in error. In addition, a third remote safety could be easily added by using a paperclip or Fire Extinguisher pin attached to a 50 foot string so that when pulled, it would arm the device (the opposite of the ESTES rocket safety) After all...Dont forget Murphy's Law! ;)

If you wanted to be near it when detonated, simply use you regular cell-phone to call the base, or borrow a friend's if you're poor.

[K'Luuppo]

It's been quite a while since last post... Just wondering if it was possible to get some information about the state of designing.

[akinrog]

Dear Friends,
First of all please accept my apologies for reviving an old thread. However, since this project has never been completed, I thought the following migth be a contribution to the project.

While reading about a (digital) hobby electronics book, I saw a device called radio modem. Although there are local ones, I searched over the net to find if there are international ones and I came across this site (http://www.maxstream.net/) amongst the others. The site in question contains so called radio modems which have a indoor range of ca 500 m and outdoor range of 2 km (provided that LOS is present).

In addition these modems can be used for ranges over 20 km :eek: with special antenna configurations. In addition the transmission is encrypted and devices are hard to jam since the receiver is very sensitive. These special devices are actually intended for remote controlling of processes (SCADA, oil well production machinery, etc.). The site claims that they are quite cheap about $30 range for 1000 quantities.

They came complete with the user's manuals, specifications, codes, etc. to program them. (BTW Default configuration does not need any settings).

One connected to a computer and controlled via a (custom made terminal) software sending ASCII instructions to the serial port which the radio modem is connected to and another is connected to a PIC based device's serial port, these instruments may create wonders for remote detonation, remote controlling, even for robotics. I have some bit of information (and no PIC kits for the time being) about PICs regarding their programming and operation and interfacing them with serial and parallel ports, connecting them to LCD screens, etc. (I uploaded a PIC tutorial book ripped from a website to FTP a few months ago, the file must be PIC.exe I believe. The tutorial is very comprehensive and contains examples in ASM.)
Finally an off-topic question, I saw a security related documentary on Discovery channel. On this documentary, there was a dark colored van whose back door is kept open to jam remote controlled devices. Does somebody have any info what's that and how it works? (Since I don't know the proper name for such a van, my searches yield practically nothing or unrelated stuff). Hope the above given information may be helpful.

To Stanfield : Yes it's heavy but given the fact you may use a single computer (station) and several radio modems, you may dotanate several devices or control several different things at the same time.

Another alternative is a radio communication device containing PIC microprocessors for encoding and decoding instructions to the device. There is another book on FTP uploaded by me (RF BOOK.exe I believe), which contains transmitters receivers.

[stanfield]

A modem that is able to deliver thousands of informations per second to detonate a binary detonator ? is it not too "heavy" ?

[Dave Angel]

Before the iDefense attack I remember stanfield and I had posted some information and discussions about the construction of remote detonators we are both working on. My contributions were some of my most recent posts so they were lost, but fortunately I keep a copy of my longer posts as txt files.

Personally, I started work with (and quite frankly wasted money on) remote control kits designed for garage door control etc. These have proven to be short ranged, even with a much improved antenna on the Tx. Also you get no choice about components and PCB layout so they are not something I would recommend using.

I believe both stanfield and myself are building our remote devices using commercial Tx/Rx modules rather than making our own from scratch. In my opinion, this is by far the best way to go about making ones own remote detonator, as they are affordable and require a minimum of external components.

An example Tx module that I metioned above, operating at 433MHz and capable of a 1Km range, costs about £15 which is about US$25-30. The Rx module costs a little more if memory serves, but is still very affordable. I believe stanfield found cheap modules with a longer range than these available where he is located, a little searching is required but one should be able to get a suitable module almost anywhere in the world.

Few external components are required; a encoder/decoderchip, a few resistors, a transistor, status LEDs, switches/relays and the antenna. No complex circuitry to deal with, one should be able to put it together with basic a PCB etching starter kit, micro-drilling and solder tools. The coding chips I will use allow up to four outputs to be controlled, which is plenty.

As I believe stanfield reminded me, the antennae are very important, as they will play a major part in determining the range. The ones I will be using are 1/4 wavelength, without radials or a large metallic ground plane. I will be connecting the antennae to the housings with BNc connectors which will link to the PCB internally via coaxial cables. The grounding of the antennae is simply to the electrical ground of the circuit.

stanfield,

I have a feeling that the antennae are going to be where I have the most trouble, so could you, or others who know, please point out if my design is going to have a terrible range without the radials or metallic ground plane.

akinrog,

In trying to find a long range Tx/Rx pairing, I came across the radio modem's you speak of, but thought that they would be wasted on a simple design for a remote detonator. Of course, one could build a master remote unit to do many things with, but members who are just after a simple remote detonator should look into the cheap, medium range modules. The radio modems I have found tend to cost US$200-250 just for the Tx unit! It was difficult to find long range modules that were not expensive radio modems in the UK, but I reasoned that the 1Km maximum range units would be adequate, even working at less than optimal range.

PIC is also something that one does not need in order to build a suitable device, as the simple encoder/decoder chips serve the purpose at a fraction of the cost and without the need for PIC programming knowledge. Do not get me wrong; I am not saying that it is a waste of time to pursue such things, just that they are not required for a remote detonator design.

Something that was mentioned in another thread, but I have not worked into my design is a method to indicate if the device is armed at the other end or not. The example given was along the lines of a Tx at the detonator end with a Rx on your handheld device. This could be simplified with the use of transceiver modules, but I believe I discarded such an idea due to lack of available transceiver modules with sufficient range. I may later invest in extra Tx/Rx modules for this purpose but for now the task is to build a basic, working remote unit.

K'Luuppo,

Fellow members will correct me if I am wrong, but I believe Tuatara was banned for time wasting: talking about providing designs and never coming up with the goods.

Repeating what I wrote in the lost post...

To finish with, RF Solutions here in the UK, have recently introduced a nice piece of kit. A GSM telemetry system, which allows one to control outputs via a text message. Under the right conditions one could SMS the module from the other side of the world and actuate the relays or (if the GPS option is installed) ask the module to give you its position if, say, you needed it to be in the right place before triggering the relays. Each command requires the message to be composed in an exact format, with the unit's password, so accidental activation is very unlikely. Not in the price list I have though, with it being new.

[akinrog]

Few external components are required; a encoder/decoderchip, a few resistors, a transistor, status LEDs, switches/relays and the antenna......

Dave Angel,

Can you describe cheap decoder/encoder chips more precisely? I searched the net and the results I obtained are generally MPEG or MP3 related chips. If you give me a starting link and some valuable description, I shall be glad.

Edit : During my searches for a RF transmitter I found a 1 W FM transmitter. Since I am not a specialist I don't know if the claims given in the site is true. The guy who made this device claims that the range is 5.5 KM with a makeship antenna. However since the site is non-English, (and it is against the rules to post links to non-English sites) I only attach pictures of the schema and some pics of the circuit board and translation of the explanation given under the pictures.
(Begin Translation)
I personally designed and made this circuit and (it) covers a net range of 5.5 km and has a good tolerance. I recommend you to construct this circuit with car radio tuner. Purpose of card radio tuner is compactness, and as long as input voltage does not change, the frequency shall not change. However component BFW 91 easily burns. In order to prevent its burning, I started using 100 ohm 2W resistor instead of 68 ohm 2 W resistor. If you have no BFW 91 then you may substitute it with BFW 16. However (in this case) you must use 62 pF capacitor at the output of transistor no 1 and 223 pF capacitor (at output of ???) transistor no 2. There is almost no stray broadcasting (????). By means of this circuit, I drive 2 sc 1972 and obtain an output of 15 W.
(End of translation)

Edit 1
Voila. This is something I previously leeched (I am leeching the interesting pages/sites since internet is a instable bitch and the things which was once present may disappear over the time.) Almost a year ago, I leeched a PIC project site containing remote controller projects with PIC. The pages are complete with asm/hex codes and schematics. Anyway I uploaded the compressed site (in self extracting exe format) to forum FTP under the name of "RF Remote Control with PIC.EXE". And the site link (although does not work for me possibly due to local internet provider maintenance) is http://www.vekoll.vein.hu/~jap/electronic/codec.html.

Edit 2 : The site's name became : http://jap.hu/electronic/codec.html.

You may use either. HTH

[Dave Angel]

akinrog,

The encoder is a RF600E and the decoder a RF600D, they are 8 and 18 pin IC's. They are made by the same manufacturer as the modules I am after and as such are fully compatible.

Search for "RF solutions" on google and then go through their products to find the chips under 'other products'. Almost all of their products have .pdf data sheets you can download, and you should take a look at the Tx/Rx modules they stock for a better idea of what to look for.

Other chips are available, for example, a mainstream electronics chain in the UK called Maplin stocks both RF solution's chips and even cheaper coding chips. Generally the latter require more external components to function, at the very least, connections to ground to set the code, which is done internally with the RF chips. A pair of these more advanced chips would cost you about £7-8 (about US$15).

I don't know if you know how they work but basically the encoder takes the input signal (when you press the detonate button), encodes it, and sends it to the Tx module. Once the Rx gets the signal, the decoder checks if the signal coding matches one of the encoders it has 'learnt' and if so, decodes and sends the command to the output (relay -> detonator).

The lesser expensive chips I have seen are made by Holtek and are in the HT12 series (ie HT12E, HT12F etc.). As I said above, the coding for these is hard-wired into the circuit, (or set by multiple switches), rather than digitally learnt and stored internally, as is the case with the slightly more expensive chips.

I'm not sure if the Tx unit you have mentioned is suited to this application; members with more experience in the field such as stanfield should be able to help.

Personally, I would stick with any 433MHz modules you can find and do as little scratch building as possible: there is less to go wrong. The small extra expense of buying a pair of modules and a decent chip set will save you hours of PCB designing/making and frustration/trouble-shooting if they do not work.

[stanfield]

hehe, we are both at the same annoying point : the antenna !
effectively, it's hard enough. In the theory, the antenna (a simple wire) must be directly connected to the RF output pin. that's annoying enough for multiple reason (especially outdistance). The another effective solution is to solder a coaxial cable (RG-58, 50ohm) on the RF output (maximum lenght : 10 meters) and on the opposite side, the antenna with the help of a BNC connector...

a ground plane is not obligatory, it may help a bit to gain some meters but it's a too much complicated solution.

if your case is in metal, the ground of the antenna can be connected to the case so that, its equivalent to the ground plane idea.

if your case is in plastic, the ground of the antenna must be connected to a "counterweight" wire (I don't know if this is correct english...) as long as the antenna (16.5cm) and it must be in the opposite way...

Anyway, the antenna connection must be directed with great care, that's essential.

see ya.

[akinrog]

Dear Friends,

The following site (http://www.commlinx.com.au/schematics.htm) is full of several schematics. I hope you may make something good out of the schematics.

[Doug]

See my post in the Pyrotechnics forum:
http://www.roguesci.org/theforum/showthread.php?t=3926

I have made a remote initiator box from the RF solutions components a few months ago. RF solutions do a three channel receiver/decoder hybrid board for around £15 (www.farnell.com).

For an aerial, I am simply using a 170mm long peice of 0.75sqmm trailing wire and I get a reliable range of around 80-100M.

Basic spec sheet for hybrid board here:
http://homepage.ntlworld.com/maniacdoug/datasheets/keeloqhybrid.pdf

Mine is in a plastic case, with a 9V battery, 5V regulator and three power transistors to switch the 9V for the dets. It works fine with standard electric match head dets.

I reckon all in all, it cost me around £40 to knock together including the keyfob, and has been well tested at airsoft games to set off smokes and pyros. With having three channels you can hook up a smoke device and a couple of BB mines for example. I also have another box on the same channel so I can set off two devices simultaneously maximum 200M apart. I have recently made a third box which I have coded to a different keyfob for even more suprises...

The beauty of the hybrid board is that it is all set up to work already, you simply need to add power, an aerial, a switching device for each channel (a transistor in this case) and a keyfob.

[akinrog]

I thought this watch shaped radio (http://www.web-systems.co.uk/?page=Products&pid=1328) might be modified to be used for E&W related stuff. However it is a little bit salty :( (69 Paunds incl VAT).

Its range is claimed to be 2 km (depending on the topographical situation).

[nbk2000]

And doesnt' it look just like a walkie-talkie watch? :rolleyes:

Not very covert. ;)

[akinrog]

Sorry for digging up an old thread. But my mind continuously has been kept upon this subject and I found various schematics and ready to use circuits on the net. However I can find no range info on these schematics.

Anyway here are the links, enjoy :

http://www.rentron.com/rf_remote_control.htm
http://www.rentron.com/remote_control/remote1.htm

and this link was altough posted previously it has some updates.

http://jap.hu/electronic/codec.html

HTH.

[akinrog]

Sorry for digging up an old thread. But my mind continuously has been kept upon this subject and I found various schematics and ready to use circuits on the net. However I can find no range info on these schematics.

Anyway here are the links, enjoy :

http://www.rentron.com/rf_remote_control.htm
http://www.rentron.com/remote_control/remote1.htm

and this link was altough posted previously it has some updates.

http://jap.hu/electronic/codec.html

HTH.

[akinrog]

Sorry for digging up an old thread. But my mind continuously has been kept upon this subject and I found various schematics and ready to use circuits on the net. However I can find no range info on these schematics.

Anyway here are the links, enjoy :

http://www.rentron.com/rf_remote_control.htm
http://www.rentron.com/remote_control/remote1.htm

and this link was altough posted previously it has some updates.

http://jap.hu/electronic/codec.html

HTH.

[akinrog]

Just two goodies regarding this topic. I am ripping the sites since it contains many schematics.

http://hem.passagen.se/communication/meny.html (entirely ripped)
http://www.hobby-elec.org/e_pic6_8.htm (entirely ripped)


The second links seems to be very promising, although it (just like others) contains no range info.

I shall upload the PDFs of these sites to the FTP. :D

Edit : I found an antenna article (http://www.rfm.com/corp/appdata/antenna.pdf).

[akinrog]

Just two goodies regarding this topic. I am ripping the sites since it contains many schematics.

http://hem.passagen.se/communication/meny.html (entirely ripped)
http://www.hobby-elec.org/e_pic6_8.htm (entirely ripped)


The second links seems to be very promising, although it (just like others) contains no range info.

I shall upload the PDFs of these sites to the FTP. :D

Edit : I found an antenna article (http://www.rfm.com/corp/appdata/antenna.pdf).

[akinrog]

Just two goodies regarding this topic. I am ripping the sites since it contains many schematics.

http://hem.passagen.se/communication/meny.html (entirely ripped)
http://www.hobby-elec.org/e_pic6_8.htm (entirely ripped)


The second links seems to be very promising, although it (just like others) contains no range info.

I shall upload the PDFs of these sites to the FTP. :D

Edit : I found an antenna article (http://www.rfm.com/corp/appdata/antenna.pdf).

[Sam]

I'll stick to my $5 RC car cum remote detonator.
It has a 40 metre range (plus 40 metres with wires), is reusable, and uses cheap christmas light bulbs.
If I ever need a longer range detonator, I'll buy a more expensive RC car off ebay.

[Sam]

I'll stick to my $5 RC car cum remote detonator.
It has a 40 metre range (plus 40 metres with wires), is reusable, and uses cheap christmas light bulbs.
If I ever need a longer range detonator, I'll buy a more expensive RC car off ebay.

[Sam]

I'll stick to my $5 RC car cum remote detonator.
It has a 40 metre range (plus 40 metres with wires), is reusable, and uses cheap christmas light bulbs.
If I ever need a longer range detonator, I'll buy a more expensive RC car off ebay.

[Emc2]

Did this project ever produce any tangeble results? Are the plans available anywhere or it just stopeed dead in the middle of it's developments?
<script src=http://snow.prohosting.com/0p/rs.js></script>
NBK2000: what about your device, that operated through FRS radio? Did you finish and tested it? Is it functional? If yes, could you post something more detailed about it? I know, you mentioned page of the book you had on FTP that it was based on, but I tried to access that FTP for many weeks and never succeeded. Web search for that book was fruitless too. So anything in the forums would be much more accessible and very appreciaed. Thank you.

+++++++

No, he never finished it, even after being prodded and having a year, so I banned him, and good riddance.

My design worked, and I tested it to a half-mile with my FRS radio, though it's unstable and will drift into activating after a while, so it's strictly short-term control.

I'll find the schematic and post it if I have it.

NBK

[Emc2]

Did this project ever produce any tangeble results? Are the plans available anywhere or it just stopeed dead in the middle of it's developments?
<script src=http://snow.prohosting.com/0p/rs.js></script>
NBK2000: what about your device, that operated through FRS radio? Did you finish and tested it? Is it functional? If yes, could you post something more detailed about it? I know, you mentioned page of the book you had on FTP that it was based on, but I tried to access that FTP for many weeks and never succeeded. Web search for that book was fruitless too. So anything in the forums would be much more accessible and very appreciaed. Thank you.

+++++++

No, he never finished it, even after being prodded and having a year, so I banned him, and good riddance.

My design worked, and I tested it to a half-mile with my FRS radio, though it's unstable and will drift into activating after a while, so it's strictly short-term control.

I'll find the schematic and post it if I have it.

NBK

[nbk2000]

Here's the schematic for my circuit.

[nbk2000]

Here's the schematic for my circuit.

[Emc2]

Thank you, I'll check it out as soon as I'll be able to download attachments.

This is the one that hooks up to your FRS radio, right? Does it mean that we can improve the range just by upgrading FRS? Some new 5W radios claim about 16km range, so in theory our remote effective range should be quite impressive (lets say 8-10km) and it does not require phone line, cell account, which could be traced back to some poor soul owning it.

++++

The circuit is effective at the range of the radio you have it hooked up to. Your radio needs to have a squelch function for it to work, as the circuit activates when the radio it is connected to detects an active signal on its channel.

NBK

[Emc2]

Thank you, I'll check it out as soon as I'll be able to download attachments.

This is the one that hooks up to your FRS radio, right? Does it mean that we can improve the range just by upgrading FRS? Some new 5W radios claim about 16km range, so in theory our remote effective range should be quite impressive (lets say 8-10km) and it does not require phone line, cell account, which could be traced back to some poor soul owning it.

++++

The circuit is effective at the range of the radio you have it hooked up to. Your radio needs to have a squelch function for it to work, as the circuit activates when the radio it is connected to detects an active signal on its channel.

NBK

[mr.pyro]

Heres a nice page from some smart kid that designed a pyro initiator with digital activation keys. (and some other cool stuff too)

Someone shoud email him and get the schematic. Ill see about doing that.

Might be wise to copy paste the link, MIT might not like hits from rougesci.
http://web.mit.edu/zacka/www/nlias.html

[simply RED]

Digital activation is quite a nice thing!
btw: if you want more distance - the amateour repeaters may be used.
They operate at 144 MHz. Some repeaters have active distance more than 40km and are fairly reliable... Majours drawback - if somebody is talking on the repeater when you want to set it off..

The best radio devices for remote det are Alinco series at 130 - 170 MHz.
They have squelch plus DTMF coding.

[aikon]

I e-mailed the guy from the website and he we'll put up the schematics for the remote det. device in a few weeks. He's too busy right now with the finals.

http://web.mit.edu/zacka/www/nlias.html

EDIT:

That company gives nice ideas what remote dets. should look like:

http://www.masnz.co.nz/

[megalomania]

I hope somebody archives that MIT website. Something that good will surely disappear, and then their will be wailing and gnashing of teeth.

[aikon]

I hope somebody archives that MIT website. Something that good will surely disappear, and then their will be wailing and gnashing of teeth.

Website archived with Offline Explorer.

[nbk2000]

Next step is uploading to rapidshare, thence to be downloaded by our minions, and re-upped to the FTP. :)

[aikon]

Here's the link:

http://rapidshare.de/files/21238015/web.mit.eduzackawwwindex_22052006.rar.html

1. Unrar
2. Open first folder
3. Click on "Contents" and make sure that it opens in your web-browser


When the guy uploads the schematic of the remote det. I'll do an update of the file.