One of our readers sent us a link to this very simple PIR circuit. It’s a really easy way to conserve battery life on any interactive project. Check out the link for a circuit diagram and more information.
When we design lighting circuit, we would like to light up the LEDs only when there is somebody around. The PIR sensor is a motion sensor based on passive infrared sensor which senses infrared emitted by human body. I got the PIR Module “KC7783R” from local store, which includes the PIR sesnor and also the KC7783 motion detection IC.
More about a Simple PIR motion sensing