Most garden watering runs on a timer and soaks everything whether or not anyone is nearby. This build flips that around: a Raspberry Pi watches the yard through a camera and only fires the sprinkler when its detection model actually spots a person. For keeping feet off a patch of freshly seeded dirt, that seems a far more targeted approach than any schedule-based system, and a much funnier one.
The hardware chain is easy to follow. A Wyze Cam V2, picked because the V3 cannot stream over RTSP, was flashed with custom firmware and strapped to a porch railing, feeding frames over WiFi into the home network. Python with opencv then decodes each frame and passes it to a YOLOv3-tiny model that decides whether a person is in view. A positive detection drives the GPIO pins, which switch a relay on a 12 volt circuit to a sprinkler controller that opens the valve and lets water reach an impact head on a spike out in the grass. Ryder Calm Down began on a Pi Zero and later moved to a Raspberry Pi 4 for more processing power.
Two details stand out to me. The maker wrote a pypi library called rtsparty that manages the latest camera frame; multithreading was already used to grab only fresh frames and fix lag caused by the buffer, and packaging that into a library seems a tidy move. There is also a Flask web server with /on and /off endpoints, which allowed manual triggering from a browser during testing.
One thing stays open: whether that grass strip is legally walkable as a public easement, a question the maker never settled. On top of that, the maker has said the whole thing was built for entertainment, calling it a super-villainy excuse, and would not recommend anyone actually copy it. Even so, as a demonstration of tying a camera, a model and a valve together, it is genuinely neat work.
Project by Ryder Calm Down. Watch it on their YouTube channel: