Build a Simple Weather Station using Arduino and DHT11 Sensor

Weather logging is a classic project for electronics beginners. Today, we will build a standalone indoor environment monitor using an Arduino board and a DHT11 sensor.

Introduction & Concept

The DHT11 sensor measures temperature and humidity using a resistive component and a thermistor. It sends pre-calibrated digital signals over a single data line to the Arduino Uno. This eliminates the need for manual analog scaling calculations.

Required Components

Component Name	Store Link
Arduino Uno R3 Board	Buy Arduino Board
DHT11 Temperature Sensor Module	Buy DHT11 Sensor

Wiring Table

DHT11 Pin	Arduino Pin	Voltage Details
VCC	5V Pin	5V Input Power
GND	GND Pin	Ground
DATA	Digital Pin 2	Digital Signal

Arduino Program Code

#include <DHT.h>

DHT dht(2, DHT11); // Configured on Pin 2

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

void loop() {
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  
  if (isnan(temp) || isnan(hum)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  
  Serial.print("Temperature: ");
  Serial.print(temp);
  Serial.print(" C | Humidity: ");
  Serial.print(hum);
  Serial.println(" %");
  
  delay(2000); // 2-second measurement gap
}