If you’re turning your house into a smart home, there are all sorts of IoT (Internet of Things) products you can purchase to do so. For instance, you might buy some smart LED light bulbs along with an Amazon Echo to control them. Smart doorbells that send a notification to your phone, and sometimes even a live video feed, are also popular. Unfortunately, they’re also expensive — usually at least $100. But if you’re a frugal type of person, you can convert your existing doorbell into a smart doorbell for just $7.
This guide comes from Nick Touran, who already has a smart home built on the open-source Home Assistant software that can run on inexpensive single-board computers (SBCs) like the Raspberry Pi. Touran lives in a tall, narrow house and has difficulty hearing his doorbell when it rings. So, he came up with a way to add the doorbell to his smart home network. He was able to do that using just an ESP8266 development board, and you can find those for as little as $7. This won’t provide a video feed, but it is capable of sending notifications or triggering some other kind of event in your smart home.
The basic idea of this setup is to connect the doorbell to the ESP8266 so that it can detect when someone rings it. When it does, it sends an MQTT (Message Queuing Telemetry Transport) message to Home Assistant via WiFi. Home Assistant can then perform any action you like. It is slightly more complicated than that, because you’ll need to be able to read the voltage drop that occurs when someone rings the doorbell. It took some experimenting on Touran’s part to get that right. But he does provide a very thorough explanation on how he got it working, so you should be able to replicate his setup.