After finding a classic service bell at an antiques store, I decided that I wanted to make a way for it to act as a physical doorbell for Hack Night. When I took it apart I saw that the bell had two metal contacts that touched whenever the bell was rung. I isolated the contacts with kapton tape and added wires that ran to an ESP32-C6 microcontroller board. I then designed an inner frame that could bolt to the inside of the bell to hold the microcontroller, an LED strip, and a LED driver. I finally purchased a relatively high capacity battery off of Amazon that fit the dimensions of the base and designed a battery holder for it that could cleanly fit in the bottom.

I then wrote some firmware for the bell that could quickly wake up, connect to wifi, and send a message over websockets to our doorbell server whenever the bell was pressed, and automatically put itself in deep sleep mode to save energy. We then started leaving it out at the door at Hack Night for people to use and it has been a fun alternative to scanning the QR code! (at least when people remember to charge it)