Meet the Mighty Paw Smart Bell: a wireless, waterproof dog doorbell with a touchpad sensor that allows your pet to communicate with you when it’s potty time. It has a 3.7″ touchpad button to allow your dog to activate the doorbell with its paw or nose. There are not wires to deal with.
Since the Smart Bell is water- and dust-proof, it can survive encounters with wet noses and dirty paws. Costs under $30 at this time.