Video Doorbell

Overview

A video doorbell is a doorbell with a camera, microphone and speaker that streams live video to a phone when someone presses it or walks up. The owner can see and talk to a visitor from anywhere, and the device records clips when it detects motion. It mounts where an ordinary doorbell would and can run on its own battery or splice into an existing doorbell transformer.

How it works

Imaging is handled by the Camera Module, an HD CMOS sensor behind a wide-angle lens with a switchable IR-cut filter for day/night operation. Compute lives on the Mainboard: a vision SoC paired with a housekeeping MCU, firmware flash, and a combo Wi-Fi/BLE radio with antenna that streams video and connects the device to the home network and app.

Detection comes from two sensor blocks. The PIR Motion Sensor uses a pyroelectric passive-infrared element behind a Fresnel lens to wake the camera on motion, and the Night-Vision Board board switches on infrared illuminator LEDs once its ambient light sensor reads darkness. Conversation runs through the Audio Subsystem subsystem, a MEMS microphone, a speaker and a Class-D amplifier for full two-way talk. A press on the Doorbell Button trips a tactile switch and lights the RGB status ring.

The doorbell is powered by the Battery Pack, a rechargeable Li-ion pack with a protection board, and can also draw from the Power Input Module module, which rectifies and regulates an existing 8–24 V doorbell transformer feed so the battery stays topped up. A separate Plug-In Chime plugs into a wall outlet and rings on press, and the whole unit fixes to the door frame on a bracket with an angle wedge and tamper-resistant screws.