LDR Based Light Intensity Monitoring Using IoT
Introduction
Objective
Components Required
Software and Platform
Working Principle
System Architecture
Expected Output
Applications
Future Enhancements
Conclusion

Published October 9, 2026 © LGPL

LuxTrack: Smart Light Monitoring Using KiwisIoT

Real-time light intensity monitoring using an LDR sensor, a microcontroller, Wi-Fi connectivity, and the KiwisIoT platform.

BeginnerFull instructions provided1 hour18

LuxTrack: Smart Light Monitoring Using KiwisIoT

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board

Jumper wires (generic)

USB-A to Mini-USB Cable

LDR Sensor Module

Software apps and online services

Kiwistron KiwisIoT

Arduino IDE

Story

LDR Based Light Intensity Monitoring Using IoT

Introduction

Light intensity monitoring is useful in smart homes, agriculture, laboratories, and energy management systems. This project uses a Light Dependent Resistor (LDR) sensor to measure the surrounding light level and sends sensor readings to the KiwisIoT platform.

Objective

The objective is to monitor ambient light intensity in real time using an LDR sensor, a microcontroller, and an IoT dashboard.

Components Required

LDR sensor

LDR sensor

Wi-Fi-enabled microcontroller

Wi-Fi-enabled microcontroller

Resistor

Resistor

Breadboard

Breadboard

Jumper wires

Jumper wires

Power supply

Power supply

Wi-Fi connection

Wi-Fi connection

Software and Platform

Arduino IDE

Arduino IDE

KiwisIoT platform

KiwisIoT platform

Working Principle

The LDR detects the light falling on its surface.

The LDR detects the light falling on its surface.

Its resistance changes according to the surrounding light level.

Its resistance changes according to the surrounding light level.

A voltage-divider circuit converts this change into a measurable voltage.

A voltage-divider circuit converts this change into a measurable voltage.

The microcontroller reads the sensor signal.

The microcontroller reads the sensor signal.

The microcontroller sends the readings to the KiwisIoT dashboard over Wi-Fi.

The microcontroller sends the readings to the KiwisIoT dashboard over Wi-Fi.

The dashboard displays the readings so changes in surrounding light can be monitored.

The dashboard displays the readings so changes in surrounding light can be monitored.

System Architecture

Ambient Light → LDR Sensor Circuit → Wi-Fi Microcontroller → Wi-Fi Network → KiwisIoT Dashboard

Expected Output

The dashboard displays the sensor readings and updates as the surrounding light changes. The raw sensor value represents an analog reading; it should not be described as a calibrated lux measurement unless a suitable calibration method is used.

Applications

Smart lighting systems

Smart lighting systems

Indoor light monitoring

Indoor light monitoring

Smart classrooms

Smart classrooms

Greenhouse monitoring

Greenhouse monitoring

IoT-based environmental monitoring

IoT-based environmental monitoring

Future Enhancements

Automatic light ON/OFF control

Automatic light ON/OFF control

Mobile notifications

Mobile notifications

Historical data logging

Historical data logging

Light-level graphs and analysis

Light-level graphs and analysis

Automatic brightness control

Automatic brightness control

Conclusion

This project demonstrates how an LDR sensor and a Wi-Fi-enabled microcontroller can be integrated with the KiwisIoT platform for remote light intensity monitoring. It provides a simple introduction to sensor interfacing and IoT-based data visualization.

Code

LIGHT MONITORING CODE

#include <ESP8266WiFi.h>
#include <KiwisIoT.h>

const char* ssid = "XXX";
const char* pass = "YYY";

const char* topic = "dash_1234";

#define LDR_PIN A0

KiwisIoT kiwisiot(ssid, pass, topic);

void sendLightData() {

  int rawValue = analogRead(LDR_PIN);

  int lightLevel = 1023 - rawValue;

  String lightStatus;

  if (lightLevel >= 700) {
    lightStatus = "BRIGHT";
  }
  else if (lightLevel >= 300) {
    lightStatus = "MEDIUM";
  }
  else {
    lightStatus = "DARK";
  }

  Serial.println();
  Serial.println("---------- LIGHT MONITORING ----------");

  Serial.print("Raw LDR Value: ");
  Serial.println(rawValue);

  Serial.print("Light Level: ");
  Serial.println(lightLevel);

  Serial.print("Light Status: ");
  Serial.println(lightStatus);

  kiwisiot.send("0", String(lightLevel));

  kiwisiot.send("1", lightStatus);

  Serial.print("Sent to KiwisIoT Channel 0: ");
  Serial.println(lightLevel);

  Serial.print("Sent to KiwisIoT Channel 1: ");
  Serial.println(lightStatus);
}

void setup() {

  Serial.begin(115200);

  Serial.println();
  Serial.println("    LDR LIGHT MONITORING    ");

  pinMode(LDR_PIN, INPUT);

  Serial.println("LDR initialized");

  Serial.println("Connecting to KiwisIoT...");

  kiwisiot.begin();

  Serial.println("KiwisIoT initialized");
  Serial.println("Starting light monitoring...");
}

void loop() {

  kiwisiot.run();

  static unsigned long lastSend = 0;

  if (millis() - lastSend >= 2000) {

    lastSend = millis();

    sendLightData();
  }

  delay(100);
}

Credits

Bala Bala

6 projects • 0 followers

LuxTrack: Smart Light Monitoring Using KiwisIoT