We will use a PIR motion detection sensor, and whenever motion is detected, the Raspberry Pi 4 Camera will take a picture and send an email with the picture attached.” Setting Up the Project ...

With just a Wemos D1 Mini, a standard PIR sensor, and some open source code, you can create a practical self-contained motion sensor module that can be placed anywhere you want to keep an eye on.

As an example, [Circuit Valley] has an IKEA Vallhorn motion sensor for a teardown, it’s as you might expect, a passive infrared sensor (PIR) sensor coupled with a Zigbee interface.