Squirt is a motion activated water cannon using Arduino.
This was designed for use in the garden but as it's winter we tested it in the bathroom. It works!
True motion tracking is expensive and complicated so this system activates when the victim moves into range and randomises the position of the cannon and the firing time within a limited area. The sometimes fickle readings from the PIR sensor just adds to the cannon's randomness, and therefore the fun.
This is my first Arduino project.