Planet Arduino

You know that guy in the next cube is sneaking in when you are away and swiping packs of astronaut ice cream out of your desk. Thanks to [Kevin Thomas], if you have an Arduino and a 3D printer, you can build a rubber band sentry gun to protect your geeky comestibles. You’ll also need some metric hardware, an Arduino Uno, and a handful of servo motors.

The video shows [Kevin] manually aiming the gun, but the software can operate the gun autonomously, if you add some sensors to the hardware.  The build details are a bit sparse, but there is a bill of material and that, combined with the 3D printing files and the videos, should allow you to figure it out.

We couldn’t help but wish for a first person view (FPV) camera and control via a cell phone, so you could snipe at those ice cream thieves while hiding in the broom closet. On the other hand, if you got the gun working, adding the remote wouldn’t be hard at all. You probably have a WiFi FPV camera on your quadcopter that finally came out of that tree and there’s lots of ways to do the controls via Bluetooth or WiFi.

Not that you don’t have options. But here at Hackaday HQ, we have lots of rubber bands and not so many green pigs. If you’d rather shoot paintballs, be careful you don’t accidentally repaint the insides of your cube.

[Farlei Heinen] has a C programming class at school. Not wanting to do another boring cookie-cutter project out of the textbook, he decided to do something different — he’s built an Arduino controlled sentry gun!

It consists of two parts: The sentry gun itself and a sonar detection tower which can tell if you’ve successfully knocked down the pigs or not. He’s using an Arduino Mega at the heart of the project, which controls the servos and reads information off of the sonar sensors.

The sentry gun uses two servo motors to control up and down, and left and right. The loading mechanism is manual, using elastic bands to launch the projectile. The firing mechanism however is a micro (9g) servo, which can release the elastic and shoot the projectile. The target is an Angry Birds toy play set made for kids.

It’s a pretty cool project, and [Farlei] has even released the source code for it if you’re interested in building your own — check it out in action, after the break!

If you’ve ever wanted to shoot someone with a Nerf gun, but just didn’t have the energy to get off the couch, this hack may be for you. It’s also a good way to ward off zombies if another apocalypse, Mayan or otherwise, is on the horizon.

Although the effects are very cool, as seen in the video after the break, the method for making this setup was quite simple. The requirements for this project were that the gun could not be permanently modified, and everything had to fire automatically. These restrictions may have contributed to the simplicity of the design as many of us would start breaking things before we had to.

Instead of some elaborate hack, the trigger was tied back in the firing position at all times. A relay was then used to interrupt the power supply to the mechanism allowing an Arduino equipped with an infrared sensor to automatically control the firing. The setup is explained after the break, but skip to around 1:55 if you’d rather just see the guns in action.