A group called NYC CNC has put together a video on creating a sentry contraption jig that assisted with a computer program, can automatically detect a target, then the shooter uses a string to pull the trigger. They say that everything can be made for $150, and it seems to work pretty well at the 5 meters they are shooting at with a .22 AR15. The actual mechanics of the rotors, and electrics is so far beyond my poor means to comprehend, so maybe some of our more knowledgeable readers can let us in how just how those work.
Of course, this contraption has no tactical or protective use whatsoever, never mind the liability involved if used in some kind of role akin to a “sentry”. But that doesn’t take away from the novelty of it, it is pretty neat!
They are using a string because of the various safeties involved and not wanting to get mixed up in liabilities of that.