Automatic Door Knocker

Automatic Door Knocker

A device that waits for someone to knock on the door and then knocks back with the same sequence of knocks.

Electronics: Microphone amplifier (left) and Arduino (right)
Electronics: Microphone amplifier (left) and Arduino (right)
Microphone mounted to the door
Microphone mounted to the door
Knocker
Knocker
Microphone and amplifier on a breadboard.
Microphone and amplifier on a breadboard.