Living objects with a body temperature above 0°C emit heat as infrared radiation, also known as thermal radiation, which is invisible to the human eye. PIR sensors, designed for this purpose, can ...

Let me introduce another simple microcontroller-based do-it-yourself circuit that detects motion and excites a light source in a flash. The “snooper” here is an ordinary passive infrared (PIR) motion ...

int pirPin = 2; // PIR sensor output connected to pin 2 int ledPin = 13; // LED connected to pin 13 (or relay module) void setup() { pinMode(pirPin, INPUT); pinMode ...