School Lockdown System

Hello, we are an engineering group working on our senior project for PLTW. We were wondering if it is possible to:

  1. Link 2 Arduino boards with wifi shields (we need wifi shields right?) such that if line of code is run on one, a light will activate on another
  2. Detect the decibel level of a gunshot, or should we use frequency?
  3. Use this detected noise to activate all of the lights in the system.

This would work in a way that if someone fires a gun on campus and the Arduino detects it, all sensors linked in the system will activate their lights. We are currently only looking to see if this is feasible and would in fact work. Thanks

ehhh .. :cold_sweat: .. uhmmm .. :disappointed_relieved: ..ahhh.. :sweat_smile: ... a real gun, you mean?

  1. Yes (if you want wifi, other wireless options exist too)
  2. You can detect either, but neither will be very reliable, will it? Depending on environment and distance between gun and sensor, both sound level and frequency can be highly distorted.
  3. Possible.

However, how large is this campus and just how many such sensor do you expect to be needed to cover it entirely? My guess is too large and way too many.

BTW, what is PLTW?

You won't be able to distinguish between a gun firing and a car back firing.

This is not really a problem in countries that have the sense to impose strict limits on firearms ownership.

I suspect, even in the USA, the probability of the system ever being needed would be so low that you could not justify its cost. Especially if one consider the miniscule value of turning lights on as a deterrent to someone (apart from the Police, perhaps) who has already decided to fire a gun.

I hope this is not a commercial project aimed at persuading frightening school authorities into spending money on irrelevant security that would be much better spent on education.

...R

Grumpy_Mike: You won't be able to distinguish between a gun firing and a car back firing.

Or probably dropping a heavy book on the ground....

...working on our senior project...

Have you considered the lawsuit that would follow if it failed to operate as required?

Lawsuit? Really? You believe someone is going to bring legal action against students whose senior project fails to operate as required?

Call me old fashioned but I suspect the only potential liability is a failing grade.

…working on our senior project…

I hope this is not a commercial project…

Oops. Failed Reading Comprehension 101.

1) Link 2 Arduino boards with wifi shields (we need wifi shields right?) such that if line of code is run on one, a light will activate on another

Yes this can be done. The noise detector arduino will be the (client) and the light activation arduino will be the (server). If you need code examples, I can help. It took me a two weeks to figure this out, as the library examples that come on the arduino library aren't very clear on how to incorporate this. If you've never used an arduino WiFi shield, I can tell you upgrading the firmware is a pain. Be prepared to spend a little time doing this, otherwise the WiFi shield won't work at all.

2) Detect the decibel level of a gunshot, or should we use frequency?

I don't know. It would be easy to detect the sound, but to identify the difference in a gunshot, verse anything else very loud would be.... difficult.

3) Use this detected noise to activate all of the lights in the system.

Cutting on all the lights in the system is easy. Identifying the particular noise that initiates this process will not be easy. In my mind, if someone screams or drops a book, the lights are going to activate.

--------------------------edit---------------------------------

This is what I would do. Obviously, you want two arduinos to communicate and lights to come on. Why not hook a Mq2 gas sensor to arduino one, and have it detect gas. It would be easy to detect if someone farts (methane), and have the lights flash. If you want it to deal with school safety, you could demonstrate if there was a gas leak in the science building the notification system would work.

[quote author=Coding Badly date=1418068324 link=msg=1993341] Oops. Failed Reading Comprehension 101.[/quote] Yes F - For some reason I assumed PLTW was the abbreviation for a company name. And I'm not used to children doing things (even protective things) involving guns.

But that does NOT mean it is a sensible project.

...R

Fort Worth uses the same basic technology to successfully locate and identify people who have used a gun in the commission of a crime. So, I strongly disagree. Continuing to develop the technology is very sensible.

But, none of that matters. Your post and mine are off-topic.

Fort Worth uses the same basic technology to successfully locate and identify people who have used a gun in the commission of a crime. So, I strongly disagree.

So you are comparing a multi million dollar professional project with a bunch of school kids with only a hazy idea of what they are doing.

Let's face it, they don't stand a chance of getting anything remotely practical. The analogue audio processing alone is worth a second year electronics degree project. That is before we look at the more difficult digital signal processing it needs.

If you also incorporate several microphones you could triangulate the origin of the bang. With an array of lasers converging on the bullet you could vaporise the it before it does any harm. I suspect you'd have a few minor wrinkles to iron out before it works flawlessly.

[quote author=Coding Badly date=1418073793 link=msg=1993483]Fort Worth uses the same basic technology to successfully locate and identify people who have used a gun in the commission of a crime. [/quote]

Grumpy_Mike: So you are comparing a multi million dollar professional project with a bunch of school kids with only a hazy idea of what they are doing.

As well as what @Grumpy_Mike says, I would need some convincing that the Fort Worth project is a good use of public money. How much does it cost per criminal convicted and how does that compare with the severity of the crime.

Much more to the point (now that I have assimilated the fact that this is a school-kids project) it seems appalling to me that this is considered by the kids themselves to be a useful or necessary project. Why are people filling kids' minds with such a frightening picture of society?

...R

Why are people filling kids' minds with such a frightening picture of society?

Because they live in a society where every social problem is attempted to be solved using a technological or medical solution.

If you want to impress, have the sensor differential between the government creating 'order' by shooting it's subjects and a citizen defending their own lives.

There are some cities in the US that already have sonic sensors on street lights / lamp posts. they time the receipt of the signal to help locate the origination of the noise. then react by moving cameras to focus on that point.

http://www.safetydynamics.net/

I know that any place I attended would have to have pop quizzes. on a planned test day a few fire crackers would. well. delay the testing.

on another note. why the whole campus ? I would want to 'light up' the red zone. Tell everyone to run away from and not panic and run in circles, maybe into the red zone.

Grumpy_Mike: Because they live in a society where every social problem is attempted to be solved using a technological or medical solution.

and the governments and media have a desire to promote chaos in order to take power from the individual. // rant mode off

dave-in-nj: and the governments and media have a desire to promote chaos in order to take power from the individual. // rant mode off

Alas, it seems to be the case in Britain as well. Terrorists under every bed. But nobody cares tuppence how many people are killed and maimed in road accidents - sell as many bigger and faster cars as you can.

...R

Thanks so much for the help/suggestions. This is a project for a grade that would be presented in front of a panel of engineers from places such as Abbott, Granger, and Boeing I believe. Besides this, what we really need is a proof of concept, nothing really drastic.

Thomas499, My group and I will definitely consider your help during our project, it will most likely be needed.

I would also like to address two concerns: 1) We as a group understand that many things could trigger the sensor such as the horn in our gymnasium or someone screaming, we could either make a proof of concept that would work theoretically given that it would not solely work with gunshots, or maybe one based on sound wave? Obviously distance to the shooter would be a problem so everything needs to be taken into account. 2) The lights that I speak of are similar to a fire alarm, when the system is activated, the lights come on to alert students. This would work similarly for what we envision but I had the feeling that some people were in need of clarification.

Thanks Again.

I hope that in your report you mention the almost total antipathy for the concept you received here from non U.S. citizens.

It is difficult to do a proof of concept on a concept that will not work on so many levels.