IocTober Day 20 - Doppler radar motion sensor

We’re creating an IoT solution for every day of “IocTober”.

You might be familiar with the “electronic eye” passive-infrared (PIR) motion sensors used in many security systems. Their characteristic tiny white dome focuses infrared radiation from warm objects (like, you know, people) onto a sensor, which reacts to any change. PIR sensors are good, and cheap, but not entirely foolproof. It’s possible to sneak past them, with skill or the right clothing.

Recently sensors using the same 2.4ghz radio spectrum used by WiFi, microwave ovens, and yes, RADAR, have become avialable that provide a more directional and reliable sensing capability.

The complexities are within the module, in use they are employed in the same way as a PIR sensor, feed them power, and they repay with a digital output indicating presence detection.