Using OpenCV library and few lines of Python code it's easy to create a simple motion detection with a Raspberry Pi.
This could be accomplished with other methods, like using a PIR sensor, but sometimes you just want to use a webcam without adding further hardware.
For this post I'm using my Sphaera configuration. This means that the video from a PiCamera is available as a web stream, but it would be easy to get your video frames from different sources...
