DIY enthusiast Arpan Mondal has constructed a musical doorbell using an ESP32 microcontroller to read the state of three white and two black 3D-printed piano keys, although it is not a full octave.
When a key is pressed, the ESP32 plays a short audio sample through a PAM8403 audio amplifier module; the output is loud enough to be heard throughout the home.
Other fun variations on the traditional doorbell include those by Hackaday, featuring a Halloween theme, and a low-energy version that connects to the Nest API and displays a moonstone when no one is home, a full moon when it is asleep, and a half moon when it is awake but nobody is at the door.
