Recently, I exhausted my stock of common passive infrared (PIR) motion sensor modules and was looking for a new one to play with. I searched the web for a small type with self-contained electronics.

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.

It should also be possible to shrink the device to the size of the PIR module, with a small custom PCB or one of the many tiny Arduino compatible dev boards. For quick manual muting, check out the ...