I need help to build a milsim prop ;)

Hi!

I mentioned the mil-sim prop made by Wizdum to a friend of mine. And he went bananas and wanted me to do something similar for their mil-sim. We decided to only make it possible to defuse it by cutting a wire. Well, since I´m really new to this I need your help. My first attempt was to hook three wires via resistors to analogue in. Defined them as input, and tried a code with "if (bluewire == LOW)" then booom! Didn't work... Any ideas how to get a wire to act as a "sensor"? The whole thing is to be placed in a metal container that you have to unscrew a few screws to open, inside there will be a mercury switch so they have to handle it with care. An LCD display with a countdown and the text armed. Three wires (red, green and blue) if you cut the right one it will "shut down" otherwise it will go off with some rgb leds and a buzzer telling them they have failed.

Happy valentines day!

when you cut the wire the pin will not go low, it floats

you need to wire it up like a switch, when you open the switch (cut the wire) then the arduino pin will be pulled high or low (depending on if your using a pull up or pull down resistor)

http://www.arduino.cc/en/Tutorial/Button

Outstanding, why didnt I think of it myself.... Thanks!

I would use an accellerometer instead of a mercury switch. You can then get a lot more information about movement and change the sensitivity (how much movement will set it off)

Mowcius

I know this is only a toy bomb but in discussing what you can do are you not giving information to those who would want to make one for real?

By definition these people are not too bright, let's keep it that way.

I know this is only a toy bomb but in discussing what you can do are you not giving information to those who would want to make one for real?

By definition these people are not too bright, let's keep it that way

That's an argument to keep all knowledge secret except for those who are "authorised" to know it, and has come up before when discussing e.g. triggering something by mobile phone. I for one would feel safer if there was a higher level of technical knowledge in the general public - people would be able to recognise what a genuine threat was, and not get into a flap about innocent things. I don't want to be regarded as a terrorist just because I'm taking a photo of something with my homemade panoramic mount...

Andrew

That's an argument to keep all knowledge secret except for those who are "authorised" to know it,

No it is not and should never be taken as such. >:(

It is just that some things are best not propagated, it is a common sense thing not a regulation thing. There are several bits of information I would rather not know (shan't tell you what they are as I don't want them known but they are not technical)

I for one would feel safer if there was a higher level of technical knowledge in the general public

Yes I would agree with that.

I am all for education but strangely I don't like being blown up by others. When I was a child I had great fun making explosives from simple pet shop ingredients but I would never dream of making it an instructable tutorial. Do you think I should?

I would never dream of making it an instructable tutorial. Do you think I should?

It would be popular. ;D

It would be popular

Yes and I would be popular as well with the security services. :o

I don't want to be regarded as a terrorist just because I'm taking a photo of something with my homemade panoramic mount...

You don't have to go that far. I was reading a book on Maps where the author was tackled just for taking ordinary photographs of the sun dials in Milton Keynes shopping centre. Apparently the security camera personnel had never seen anyone taking a picture before.

An accelerometer is a good idea but I like the old school look if a glass mercury switch so I'm sticking with that.

Mike, your first mistake is in assuming that terrorists are a bunch of uneducated backwoods ****.

The intelligence community knows otherwise (and this has been publicized on NPR, at least).

These people are in general intelligent, and with a little thought one can understand their motives, even if they are misguided and/or extreme. I highly doubt that discussion of how to build a fake device on this list is going to change what they do one way or another; I also doubt that they would use an Arduino or such anyhow given how easy it is to use other, more common parts.

With that said, this thread is likely to get too political, so I am leaving it at that. About the only thing I didn't like was the thread's topic line; threads (and people) on other forums have been at least approached by agents for posting less interesting statements than that...

The OP just might get his own visit...

8-)

I live in Sweden and work as an 1st Lt. in the air force so I don't think I´ll get any visits from people who think I'm a terrorist :)

However the topic has been changed to something less eye catching.

You don't have to go that far. I was reading a book on Maps where the author was tackled just for taking ordinary photographs of the sun dials in Milton Keynes shopping centre. Apparently the security camera personnel had never seen anyone taking a picture before.

That's the sort of thing I worry about, especially as I live in Milton Keynes...

Back on topic, a mercury tilt switch with the mercury visibly sloshing around would be very cool.

Andrew

An accelerometer is a good idea but I like the old school look if a glass mercury switch so I'm sticking with that.

A few things to bear in mind... - Mercury is a poison - Mercury is especially dangerous to children - Mercury can be absorbed through the skin and mucous membranes - Mercury has been known to evaporate at low temperatures - Vapors can be breathed-in - Glass has a tendency to break - A bomb simulator is very likely going to be treated roughly (maybe even thrown or kicked in frustration)

Coding Badly

I appreciate your concern
However the device will not be handled by children and I plan to scavange the switch from an old device, so instead of it getting thrown away and burned up in the local dump the mercury will be in a controlled enviroment until I dispose of it properly.
I find it unlikley that any of the players will handel the device roughly since that is bad sportsmanship and will cause them to be shut off from any further events (and they will have to pay for the device and the cleaning of any mercury that have been released).

I also plan to connect a relay just to get a satisfying CLICK if they cut the right wire and disarm the device.

live in Sweden and work as an 1st Lt. in the air force so I don't think I´ll get any visits from people who think I'm a terrorist

Major Nidal Hasan was an even more senior officer than you.

Groove, why are you comparing me to this man? And what does rank have to do with menatlly instable persons? Can we please keep to the topic since this is the arduino interfacing forum.

I'm not comparing him to you (nor vice versa), but simply stating you're a junior officer in any kind of military service does not preclude you from being under any kind of suspicion.

... Yet again, can we keep to the topic?

can we keep to the topic?

OK. Don't use Hg. Ever.