[ladyada] has a freshly-published and amazingly thorough tutorial on passive infrared (PIR) motion sensors. Most often seen in security floodlights and automatic doors, in creative hands these sensors ...

Last year, I took a look at some mostly low-cost passive infrared (PIR) motion sensor modules. Then recently, I became more aware of cheap microwave radar motion sensor modules. The popular version of ...

There’s no shortage of ESP32 development boards out there, with many of them offering some “killer app” feature which may or may not align with whatever it is you’re trying to do. But if you’ve got a ...