Scarecat

This thing is an automated water spray repellant.

Arduino based; a servo motor pushes up a bottle of water spray, thus expelling a jet of water when a distance sensor is triggered by an object passing by. Powered via micro-usb and using a 18650 battery for backup.

Used to train pets such as cats by providing a systematic reaction to the subject when detected at a location it should not be (e.g. on a table).