Overview
Things
Story

Step 1: Connect the DHT11 Sensor to NodeMCU :
Step 2: Configure the Arduino IDE :
Step 3: Upload the Program :
Step 4: Configure the KiwisIoT Dashboard :
Step 5: Connect the ESP8266 to Wi-Fi :
Step 6: Monitor the Data on KiwisIoT :
Working Principle :
Applications :

Sudhakar N • Posted by Sudhakar Natarajan

Published September 4, 2026 © Apache-2.0

ESP8266 Temperature and Humidity Monitoring System

An IoT-based system using NodeMCU ESP8266 and DHT11 to monitor live temperature and humidity through the KiwisIoT dashboard.

BeginnerProtip30 minutes22

ESP8266 Temperature and Humidity Monitoring System

Things used in this project

Hardware components

NodeMCU ESP8266 Development Board

DHT11 Temperature & Humidity Sensor (4 pins)

Jumper wires (generic)

USB-A to B Cable

Software apps and online services

Arduino IDE

Install at local desktop

KiwisIoT Platform

I had attached the KiwisIoT Platform Link - https://kiwisiot.in

Story

Step 1: Connect the DHT11 Sensor to NodeMCU :-

Connect the DHT11 sensor to the NodeMCU ESP8266 as follows:

DHT11 → NodeMCU ESP8266

VCC → 3.3V
DATA → D4 or the pin configured in the program
GND → GND

Ensure that the wiring is properly connected before powering the NodeMCU.

Connecting setup

Step 2: Configure the Arduino IDE :-

Install the ESP8266 board package using the Arduino IDE Boards Manager.

Then select:

Tools → Board → ESP8266 Boards → NodeMCU 1.0 (ESP-12E Module)

Install the required libraries:

DHT Sensor Library
Adafruit Unified Sensor Library
KiwisIoT LibrarySelect the correct serial port before uploading the program.

Step 3: Upload the Program :-

After completing the hardware connections, upload the program to the NodeMCU ESP8266.

The program performs the following operations:

Initializes the DHT11 sensor.
Connects the ESP8266 to Wi-Fi.
Reads temperature data.
Reads humidity data.
Sends the sensor values to the KiwisIoT dashboard.

Step 4: Configure the KiwisIoT Dashboard :-

Create a dashboard on the KiwisIoT platform and add widgets for displaying the sensor readings.

Configure:

Temperature Display
Humidity Display

Once the ESP8266 starts sending data, the dashboard widgets will display the sensor values in real time.

Step 5: Connect the ESP8266 to Wi-Fi :-

Values Displayed at the Serial monitor

Power the NodeMCU using the USB cable and upload the program.

After starting the device:

The ESP8266 connects to the configured Wi-Fi network.
The DHT11 sensor begins collecting temperature and humidity data.
The ESP8266 sends the readings to KiwisIoT.

The Arduino Serial Monitor can be used to verify the sensor readings and data transmission.

Step 6: Monitor the Data on KiwisIoT :-

Open the KiwisIoT dashboard after the ESP8266 successfully connects to Wi-Fi.

The dashboard displays:

Live Temperature
Live Humidity

The values are updated continuously based on the sensor readings.

Working Principle :-

Applications :-

This project can be used for:

Smart Home Monitoring
Indoor Environmental Monitoring
Smart Agriculture
Greenhouse Monitoring
Weather Monitoring
Industrial Environmental Monitoring
IoT Data Logging
Remote Environmental Monitoring

Code

Upload code at the ESP32 Board

#include <KiwisIoT.h>
#include <DHT.h>

const char* ssid = "IOT";
const char* pass = "12345678";
const char* topic = "dash_1787738664437";

KiwisIoT kiwisiot(ssid, pass, topic);

// DHT11 configuration
#define DHT_PIN D5
#define DHT_TYPE DHT11

DHT dht(DHT_PIN, DHT_TYPE);

void setup() {
Serial.begin(9600);

dht.begin();

kiwisiot.begin();
}

void loop() {
kiwisiot.run();

float temperature = dht.readTemperature();
float humidity = dht.readHumidity();

// Check whether DHT11 reading is valid
if (isnan(temperature) || isnan(humidity)) {
Serial.println("Failed to read from DHT11!");
delay(2000);
return;
}

// Send temperature to widget ID 1
kiwisiot.send("1", temperature);

// Send humidity to widget ID 2
kiwisiot.send("2", humidity);

Serial.print("Temperature = ");
Serial.print(temperature);
Serial.println(" °C");

Serial.print("Humidity = ");
Serial.print(humidity);
Serial.println(" %");

delay(2000);
}

Credits

Sudhakar N

Posted by

Sudhakar Natarajan

ESP8266 Temperature and Humidity Monitoring System