Humans and other warm objects emit heat in the form of IR radiation. This sensor uses changes in IR radiation to detect motion in front of it, and sends out a simple digital signal that can be read by any microcontroller. We designed PIR Stick to handle the very important business of triggering motion effects on our Tiny FX models so it comes with a cable that will let you plug it straight in to the three pin connector on Tiny FX. If you're planning on using it with another microcontroller, you'll probably want to pick up a JST-SH to DuPont cable to connect it up. We also have loooooong JST-SH to JST-SH cables available if you want to position your PIR Stick further away from your model.