# PIR Motion Detector

Day 12 of the 100 Days 100 IoT Projects collection. Board: Pi Pico.

A PIR sensor on the Raspberry Pi Pico 2W flashes the onboard LED when movement is detected. The classic motion-sensing hello world.

## How it works

The PIR sensor watches for changes in infrared radiation, which is what a warm moving body produces against a cooler background. When it fires, its output pin goes high and the Pico lights the onboard LED. After a cooldown window it re-arms itself.

## What you'll learn

- Pyroelectric motion sensing
- Digital sensor inputs
- Retrigger timing
- Onboard LED as indicator

Full project (code, wiring diagram, Wokwi simulation): https://github.com/kritishmohapatra/100_Days_100_IoT_Projects/tree/main/PIR_Motion_Detector_using_Raspberry_Pi_Pico_2W_&_MicroPython

Summary by SkillShop. Code and diagrams belong to the original repo.