If not, then it may be located near a wired doorbell chime. Before you start the install, turn off the circuit breaker. Rachel Cericola/NYT Wirecutter Check what voltage your transformer puts out ...

Installing a video doorbell requires only ... Step 2: Find and Inspect Your Doorbell Transformer Use a multimeter set to "AC ...

He reasoned that he could tap into the low-voltage side of the doorbell transformer and watch for the telltale fluctuations that would indicate the bell was doing its thing. The ESP8266 has an ADC ...