IoT Based Motion Detector

Updated: Jul 2, 2021

In this tutorial. To learn how to interface PIR(Passive infrared) motion/intrusion detection sensor with nodemcu WiFi module, Buzzer alarm. PIR motion sensor will instantly detect the presence of it and rings a buzzer alarm to notify you about an intrusion.


The project can be taken as a small security system and could be installed in garage, garden(to check the presence of wild animals dogs, cats, pigs, birds etc), house, pet house, shops and stores. Live body emits heat waves and heat waves contains infrared rations. The more the body emitting heat the more the infrared radiations. Generally the living bodies emit more heat than the raw materials. So pir sensor can be used to detect the motion of living bodies.


Circuit Diagram


Components Required

  • NodeMCU ESP8266 12E

  • Motion Sensor HC-SR501 (PIR Sensor)

  • LCD 16x2 with I2C Module

  • Buzzer

  • Jumper Wires


PIR motion sensor

The HC-SR501 module uses a passive infrared sensor and an integrated circuit (IC) to detect motion. It features adjustable sensitivity that allows for a motion detection range from 3 meters to 7 meters. The module also includes time delay adjustments and trigger selection for fine tuning.