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 ...

In this configuration, your existing doorbell transformer will trickle charge the battery ... This section can be filtered by event type and date, so it’s generally pretty quick to find an event that ...

Power Runs on a built-in, rechargeable battery. Can be hardwired to an existing doorbell system or transformer for continuous charging (8-24 VAC, 40VA max, 50/60Hz). No halogen or garden-lighting ...

An existing wired doorbell rings a buzzer, but this cannot be heard in ... inside a small food container screwed to the wall under the stairs. Rather than use a transformer to power the Pi I replaced ...

The device works with compatible doorbell transformers, requiring a 16-24VAC, 10-40VA rated doorbell transformer and chime, which are sold separately. You may need to replace existing hardware.