Auto-Tracking Sentry Gun Gives Deer A Super Soaking

Things rarely go well when humans mix with wildlife. The problems are exacerbated in the suburbs, where bears dine on bird feeders and garbage cans, raccoons take up residence in attics, and coyotes make off with the family cat. And in the suburbs, nuisance wildlife can be an intractable problem because the options for dealing with it are so limited.

Not to be dissuaded in the battle to protect his roses, [dlf.myyta] built this motion-activated sentry gun to apply some watery aversion therapy to marauding deer. Shown in action below against a bipedal co-conspirator, the sentry gun has pretty much what you’d expect under the hood — Raspberry Pi, NoIR camera, a servo for aiming and a solenoid valve to control the water. OpenCV takes care of locating the intruders and swiveling the nozzle to center mass; since the deer are somewhat constrained by a fence, there’s no need to control the nozzle’s elevation. Everything is housed nicely in a plastic ammo can for portability and waterproofing. Any target that stands still for more than three seconds gets a hosing; we assume this is effective, but alas, no snuff films were provided.

We’re not sure if [dlf.myyta]’s code can discern friend from foe, and in this litigious world, hosing the neighbor’s kid could be a catastrophe. Perhaps version 2.0 can include image recognition for target verification.

29 thoughts on “Auto-Tracking Sentry Gun Gives Deer A Super Soaking

  1. Everything is housed nicely in a plastic ammo can for portability and waterproofing.

    And the fan opening cut into the side renders the waterproofing ability of the ammo can irrelevant.

    1. I was wondering what the hell in there needs forced air cooling. Surely not the pi. I’d love to see a cell phone with an aftermarket heatsink and fan, which is about the same idea.

  2. I’ve got to get something in place for tomato season later this year. The next squirrel that picks a tomato gets a bath. I’ll either end up with more tomatoes or very clean squirrels.
    (I mean really, how evil does a creature need to be to take one bite out of a tomato and then drop it on the ground.)

    1. I watched a bastard of a black bear tear down an apple tree that my wife planted when we moved into our house. Caught the whole thing on the security camera. He reached for one apple at the top, yanked the whole tree down, and just walked away. Jerk.

    1. The bitterant (in “canned air”) would pretty much render the crops uneatable.
      This damned stuff has been put in almost everything nowdays, due to the huffers/drinkers.
      It will linger on your tools and cause a cross contamination for a long time.
      Loooaaads of fun when you inadvertently get it on your fingers and then handle contact lenses.
      Normal hand washing wont get it from under fingernails.
      Second-hand computer gear can be problematic for contamination with it.

  3. Umbrellas are essential for rogue turkey defense!

    Since plain water can be discharged from a car legally, could this deal with Bambi (bam-bye) incidents? How about a network of these along known deer zones.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.