DIY: Autonomous Sentry Turret

So you are looking for an automated solution to keep intruders away? This Autonomous Sentry Turret might do the job (with some modifications). It is a system capable of detecting intruders and grabbing their attention with a barrage of soft foam darts. Of course, you could make small modifications to make it more painful for strangers.

You are going to need an Intel Edison with Arduino breakout, an electric Nerf gun, a PIR sensor, and a few other parts to get started. More information is available on Instructables.