This project uses an Arduino Uno and a DHT11 sensor to measure temperature and humidity, calculate the heat index, and display the data on the serial monitor.
In this lesson, you’ll learn how to measure temperature and humidity, as well as calculate the heat index using a DHT11 sensor with an Arduino Uno. We’ll cover reading and interpreting data from the DHT11 sensor, and displaying these values along with the heat index in both Celsius and Fahrenheit on the serial monitor. This project is perfect for Arduino beginners, providing hands-on experience with sensors and data handling in a simple yet engaging way.
Components and Supplies
1 USB-Cable - Buy Now
1 DHT11 Humidity & Temperature Sensor Module - Buy Now
1 Jumper-Wires - Buy Now
1 Arduino-Uno - Buy Now
1 Breadboard- Buy Now
Step 1: Gather the Required Components
Before starting, make sure you have the following components:
Arduino Uno – The microcontroller board used for processing sensor dataDHT11 Temperature & Humidity Sensor – The sensor that measures temperature and humidity Breadboard – Used for circuit prototyping
Jumper Wires (Male-to-Male) – For making connections
USB Cable – To connect the Arduino to the computer for programming and power
Step 2: Circuit Connections
Now, let’s wire the DHT11 sensor to the Arduino Uno as shown in the diagram below.
Step 3: Install the DHT11 Library in Arduino IDE
Before writing the code, we need to install the DHT11 library in Arduino IDE.
Steps to Install the Library:
Open Arduino IDE.
Go to Sketch → Include Library → Manage Libraries.
In the search bar, type “DHT sensor library”.
Install "DHT sensor library by Adafruit".
Step 4: Code
#include <DHT.h>
#define DHTPIN 2 // Connect the Data pin of DHT11 to Digital Pin 2
#define DHTTYPE DHT11 // Define the sensor type
DHT dht(DHTPIN, DHTTYPE);
void setup() {
Serial.begin(9600);
dht.begin();
}
void loop() {
float humidity = dht.readHumidity();
float temperatureC = dht.readTemperature(); // Read temperature in Celsius
float temperatureF = temperatureC * 1.8 + 32; // Convert to Fahrenheit
float heatIndexC = dht.computeHeatIndex(temperatureC, humidity, false); // Heat index in Celsius
float heatIndexF = dht.computeHeatIndex(temperatureF, humidity); // Heat index in Fahrenheit
Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print(" %\t");
Serial.print("Temperature: ");
Serial.print(temperatureC);
Serial.print(" °C / ");
Serial.print(temperatureF);
Serial.print(" °F\t");
Serial.print("Heat Index: ");
Serial.print(heatIndexC);
Serial.print(" °C / ");
Serial.print(heatIndexF);
Serial.println(" °F");
delay(2000); // Wait for 2 seconds before updating values
}
