My ONE post on gun control

March 17, 2013 Posted by bob in Personal Projects

This post is about my attempt at a technological solution to gun problems. I built a working prototype, but ultimately I believe that this is not a solution to the problem of mass shootings. There is no technological solution that will prevent someone who is sufficiently motivated from doing significant harm yet still afford us the freedoms that make us human. However, what I built can help prevent people from harming others with knives sometimes, check the best knife sharpeners for the money . It has some legitimate circumstances in which it could be very effective.


I was approached by a guy who recognized my wireless communications skills and proposed an idea to me. He had been thinking since the Sandy Hook shooting about how guns could be made safer, and thought that some kind of token that people wore that could disable weapons would be a great solution. Essentially he wanted to create a movement where people carried these tokens that emitted a disable signal, and he thought that governments could be convinced to mandate that all guns listen for this signal and refuse to fire when the disable signal is detected. That was where we started.

Evolution of the idea

Clearly this idea had problems. First was socio-political. Getting a government to mandate this would be impossible, getting people to trade in their guns would be impossible, preventing gun smuggling would be impossible, and establishing exceptions for military and police would be a loophole filled nightmare that would render the system useless. The next problem was technological. A token that’s always emitting a signal would run out of batteries quickly. A weapon that could automatically disable itself would be tricky. And a system that only deactivates if it hears a deactivate signal can easily be foiled by… aluminum foil. Wrapping the gun in aluminum foil would prevent the signal from reaching the antenna.

It took a lot of back and forth to come to a final solution, and it still has flaws. But we’ll get to that later. And I have no way to address the political or social problems; I’m a technical guy and that is a job for someone else. Here’s what we ended up with:



The four parts: the weapon, enable token, disable token, and plugin disable token.

The four parts: the weapon, enable token, disable token, and plugin disable token.

1) An enable token with a button that emits an ‘enable signal’ repeatedly while it’s turned on. We’re using Bluetooth Low Energy because this is exactly the sort of thing BLE was designed for. Low energy wireless communications. The enable token is paired with the weapon so that only that enable token can enable that particular weapon. This means the weapon will not enable unless the enable token is on, and within range. This prevents people from using stolen weapons, or getting into their parents’ guns, or accidentally firing, and can also prevent a gun from being used against its owner. This enable token alone is what makes this system great. There are far more accidental shootings, shootings with stolen weapons, and attacks against the owner than there are mass shootings, and an enable token paired to a gun would prevent a lot of those. But the enable token also serves another important purpose. Remember how you could just wrap a gun in aluminum foil so it doesn’t get any disable signals? Well if the gun needs to hear an enable signal, it can’t do that while covered in aluminum foil. So the fact that the gun has to hear a signal to enable means it must be capable of hearing a signal to disable.

2) The weapon with a receiver (and optionally a transmitter). The weapon has an electromechanical device that is connected between the safety and the firing mechanism. When the safety is diesngaged, this module is powered on, and when it hears the right enable signal, and no disable signals, it will allow the gun to fire. As soon as it hears a disable signal or stops hearing the enable signal, it will disengage and the weapon will not fire.

3) A disable token that emits a ‘disable signal’ every few seconds. Essentially this beacon says to any specially equipped guns “please don’t fire near me.” Any weapon or enable token within range will immediately disable itself. Another advantage of using Bluetooth Low Energy is that many cell phones are now coming with BLE capability built in, which means eventually a cell phone could be emitting this disable beacon. So people wouldn’t need to carry an additional piece of electronics; it would be an app they could download and run in the background.

4) Finally, a fourth device can plug into a wall and emit a disable signal regularly. It could also be listening for enable signals that would indicate someone is trying to enable a gun. And if the gun were emitting a signal saying “hey, I’m a gun and someone is trying to fire me” it could listen for that as well. It would have a siren and possibly other ways to indicate authorities that a gun was trying to be used in a certain area.


I ordered some fake guns from Amazon, some Bluetooth modules from BlueGiga, and designed some parts for the enclosures. Writing the software for the Bluetooth modules, building the circuits, 3D printing the parts, assembling it all, and testing it, took a relatively short amount of time. A few weeks, really, and that was just in my spare time. It’s only prototypes, so I wouldn’t want to mass produce them the way I built them, but for a working prototype, it works and looks acceptable.

One thing I skipped was designing the electromechanical part that would prevent a gun from firing. I justified this by saying that many guns would be different in their implementation, and I don’t have a real weapon to develop for, and we were trying to prove the wireless concept.


Here are a few of the problems I ran into.

  • Range: Of course, you’re preventing guns that are within range, not bullets. A gun that is sufficiently far that it doesn’t get a disable signal will still be able to fire INTO an area.
  • Aluminum Foil: It’s still entirely possible to put the enable token INSIDE the aluminum foil surrounding the weapon so that it gets the enable signal and not a disable signal.
  • Timing: A disable signal should be sent infrequently to conserve battery life, prevent collisions, and keep the airwaves mostly clear. But the longer it is the more opportunity to not hear it. A weapon could be enabled and fired in between disable signals. We tried to get around this by disabling for at least five seconds after hearing a disable signal, but if the weapon is turned on, enabled, and fired before the first disable signal reaches it, there’s at least one bullet getting shot. Yes it prevents further shots, but one is enough to do damage. You can see in the video that the gun is enabled briefly before it receives a disable signal.
  • Safety: Usually when a gun is being fired, timing is critical, and having to wait for your gun to enable before you can fire it could mean life or death. That’s why it’s critical that the enable happens immediately every time.
  • Bad guy has a regular gun and a disable token: So he can prevent you from firing, but he is unaffected. Unless the world has 100% adoption of this system, there will be guns that have an edge over other guns, and that makes this system undesirable.
  • Batteries: Yes, it has batteries. Batteries run out. Then you’re in trouble.
  • Gunk: When weapons fire, there’s an explosion, and then powder gets all over the place. On guns it’s really hard to keep this powder from getting all over. Further, there’s not a lot of room in a lot of guns for the firing mechanism to attach to the trigger since it has to wrap around the magazine, so it’s a tiny space that could easily get filled with stuff that could prevent it from working.


  • Safety: Guns can only be fired if the enable token is on, which means fewer accidental firings.
  • Theft deterrence: A gun without its enable token is useless, so the owner (who should still be responsible about protecting his gun), can add protection by keeping his enable token separate from his guns.
  • More difficult to misuse guns: It’s not a failsafe system, but it adds a layer of security and challenge that may deter some people.


This is my contribution to the conversation. I built something that has the potential to solve some problems for some people. But after developing and considering the situations in which this might not work, and the motivations behind the gun makers, legislators, gun owners, and gun shooters, this system, and any other like it, has too many holes and challenges to make it a cure-all for gun control. We shouldn’t be applying technology like this to guns because it defeats their purpose and doesn’t solve the real problem that exists with the person holding a weapon.

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