Introduction

Monitoring room occupancy is an important feature in smart homes, offices, classrooms, and commercial buildings. Detecting human presence helps improve security, optimize energy consumption, and automate lighting or air-conditioning systems.

This project uses an ESP8266 NodeMCU with a PIR Motion Sensor (HC-SR501) to detect human movement inside a room. An LED provides a local indication whenever motion is detected. The ESP8266 sends the occupancy status to the KiwisIoT cloud platform using the MQTT protocol over Wi-Fi, allowing users to monitor room occupancy in real time through a web dashboard.

Hardware Components Required

S.No	Component	Quantity
1	ESP8266 NodeMCU	1
2	PIR Motion Sensor (HC-SR501)	1
3	LED	1
4	220Ω Resistor	1
5	Breadboard	1
6	Jumper Wires	As Required
7	Micro USB Cable	1

Step 1 – Hardware Connections

Connect the components as follows:

NODE MCU

NodeMCU ESP8266 Pinout, Specifications, Features & Datasheet

PIR Motion Sensor

VCC → VIN (5V)

GND → GND

OUT → D4

LED

Positive (Anode) → D5 (through 220Ω resistor)

Negative (Cathode) → GND

Note: The PIR sensor detects infrared radiation emitted by the human body. When motion is detected, the sensor output becomes HIGH and the LED turns ON.

Circuit Diagram

Figure 1: Hardware Connections of the Room Occupancy Monitoring System.

Step 2 – Configure the KiwisIoT Dashboard

Login: https://kiwisiot.in/login

Create a Dashboard

Sign in to KiwisIoT.

Create a new panel.

Copy the generated Topic ID.

Replace it in the Arduino code.

const char* topic = "dash_xxxxxxxxxxxx";

Add Widgets

Room Occupancy Status (Display)

Channel Mapping

Channel 1 → Occupancy Status

The dashboard is now ready to receive live MQTT data.

Step 3 – Upload the Program

Required Libraries

ESP8266WiFi

KiwisIoT

Also install the ESP8266 Board Package from the Arduino Boards Manager.

Configure Wi-Fi

const char* ssid = "YOUR_WIFI";

const char* pass = "YOUR_PASSWORD";

const char* topic = "YOUR_TOPIC";

Replace these values with your Wi-Fi credentials and KiwisIoT Topic ID, then upload the provided Arduino program.

Upload the Program

/*

----------------------------------------------------

Project : IoT-Based Room Occupancy Monitoring System

Author : Varun Prasad

Features:

- Human Motion Detection

- Room Occupancy Monitoring

- LED Occupancy Indicator

- Real-Time Cloud Monitoring using KiwisIoT

----------------------------------------------------

*/

#include <ESP8266WiFi.h>

#include <KiwisIoT.h>

//--------------- Wi-Fi ----------------//

const char* ssid = "YOUR_WIFI";

const char* pass = "YOUR_PASSWORD";

const char* topic = "YOUR_TOPIC";

KiwisIoT kiwisiot(ssid, pass, topic);

//--------------- Pins ----------------//

#define PIR_PIN D4

#define LED_PIN D5

void setup()

{

Serial.begin(115200);

pinMode(PIR_PIN, INPUT);

pinMode(LED_PIN, OUTPUT);

digitalWrite(LED_PIN, LOW);

kiwisiot.begin();

}

void loop()

{

kiwisiot.run();

int motion = digitalRead(PIR_PIN);

if (motion == HIGH)

{

digitalWrite(LED_PIN, HIGH);

Serial.println("Room Occupied");

kiwisiot.send("1", "Occupied");

}

else

{

digitalWrite(LED_PIN, LOW);

Serial.println("Room Empty");

kiwisiot.send("1", "Empty");

}

delay(1000);

}

How To Upload Code?

Refer This →

https://kiwisiot.in/test/blog/esp8266-code-upload

Program Functions

Connects to Wi-Fi and KiwisIoT.

Detects human motion using the PIR sensor.

Determines whether the room is occupied or empty.

Turns ON the LED when motion is detected.

Uploads the occupancy status to the KiwisIoT dashboard every second.

Displays the occupancy status in the Serial Monitor.

Step 4 – Live Monitoring

After uploading the code, the ESP8266 connects to Wi-Fi and starts sending occupancy data to the KiwisIoT dashboard.

The dashboard displays:

Room Occupancy Status

When a person enters the detection area of the PIR sensor, the dashboard status changes to Occupied, and the LED turns ON. When no motion is detected, the status changes to Empty, and the LED turns OFF.

Applications

Smart Home Automation

Office Occupancy Monitoring

Classroom Monitoring

Meeting Room Monitoring

Smart Building Management

Energy Saving Systems

Educational IoT Projects

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