Published April 2, 2026 © GPL3+

Smart Motion Sensor Light with ESP32

An ESP32-based motion sensor light that automatically turns on in the dark, saving energy and improving home automation.

BeginnerWork in progress2 hours16

Things used in this project

Hardware components

M5Stack M5StickC ESP32-PICO Mini IoT Development Board

STEMpedia PIR Motion Sensor (HC-SR501)

LED (generic)

ControlEverything.com 1-Channel Signal Relay 1A SPDT I²C Mini Module

Resistor 10k ohm

Breadboard Mates Pi Adaptor

Jumper wires (generic)

SparkFun Breadboard Power Supply 5V/3.3V

Story

The idea behind this project was to create a simple, practical, and energy-efficient lighting solution that can be used in everyday environments like hallways, staircases, and entry points.

Traditional lighting systems often remain ON unnecessarily, leading to energy waste. To solve this problem, I decided to build a smart motion-activated light using an ESP32 and a PIR motion sensor. The goal was to design a system that only activates when human presence is detected, making it both efficient and convenient.

The system works by continuously monitoring motion through the PIR sensor. When movement is detected, the ESP32 processes the signal and instantly turns on the connected light source. After a predefined delay, the light automatically turns off if no further motion is detected. This ensures optimal energy usage without requiring manual control.

Additionally, this project can be easily extended by integrating an LDR sensor for day/night detection or connecting it to IoT platforms for remote monitoring and control.

During development, the focus was on keeping the design simple, cost-effective, and beginner-friendly, while still demonstrating real-world application potential.

This project is ideal for:

Smart home automation
Energy-saving systems
Security lighting
DIY electronics learning

Overall, this build highlights how small hardware systems can solve real-life problems efficiently while serving as a foundation for more advanced automation projects.

Code

ESP32 Motion Sensor Light Code

#define PIR_PIN 13
#define LED_PIN 12

int motionState = LOW;

void setup() {
  pinMode(PIR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  motionState = digitalRead(PIR_PIN);

  if (motionState == HIGH) {
    Serial.println("Motion Detected!");
    digitalWrite(LED_PIN, HIGH);
    delay(5000);  // Light stays ON for 5 seconds
  } else {
    digitalWrite(LED_PIN, LOW);
  }
}