Alarm Kits, Motion Sensors and Smart Home Detectors

Starter kit or single sensors: how to build a system

An alarm starter kit gives you a base station, a keypad and a few sensors that already talk to each other, which is the simplest route. Single sensors suit adding a detector to an existing system or hub. The usual pieces are contact sensors for doors and windows, motion detectors for hallways and rooms, and a siren. Motion sensors respond to heat, so pet-immune models, which ignore animals up to a stated weight, suit homes with cats and dogs.

Radios, batteries and the clocks mixed into this aisle

Sensors use Wi-Fi, Bluetooth, Zigbee or a maker's own radio. Zigbee sensors need a hub, and a kit's sensors normally work only with their own base. Most run on coin cells or AA batteries, though some have a built-in rechargeable cell, so check the battery type and how the app warns you about low power. A few digital alarm clocks are listed here as well; they wake you up rather than guard a door, so check the product type before relying on a listing for protection.

Questions about Alarm Kits, Motion Sensors and Smart Home Detectors

Will a motion sensor go off when my pet walks by?

A standard sensor detects body heat and movement, so it can. Pet-immune models ignore animals below a stated weight, and mounting height and angle also matter. Check the weight rating in the listing before relying on it.

Do alarm sensors need a hub?

Wi-Fi sensors connect directly to your router, but Zigbee and many kit sensors need their own hub or base station. Check the protocol in the listing and whether the kit includes the base.

How many sensors does an apartment need?

A door sensor on every entry door, a motion sensor covering the main hallway or living area, and window sensors where windows are reachable from outside. Larger homes add detectors floor by floor.