The DHT11 sensor is a popular and affordable sensor used for measuring temperature and humidity in many electronics and IoT projects.
📌 Key Features:
Temperature Range: 0°C to 50°C (±2°C accuracy)
Humidity Range: 20% to 90% RH (±5% accuracy)
Operating Voltage: 3V to 5.5V
Digital Output: Sends data using a single-wire protocol
Sampling Rate: 1 reading every second (1Hz)
🧠 Working Principle:
The DHT11 uses a thermistor for temperature and a capacitive humidity sensor for measuring moisture. A small microcontroller inside the module processes the sensor data and sends it as a digital signal to a connected microcontroller like Arduino or NodeMCU.
🔌 Pinout:
VCC – Power supply (3.3V or 5V)
DATA – Serial data output
GND – Ground
📘 Applications:
Home automation systems
Weather stations
Greenhouse monitoring
IoT-based health/environmental monitoring
 
 
Sample codes
 
#include "DHT.h"
#define DHTPIN 2      // Digital pin connected to the DHT11
#define DHTTYPE DHT11 // DHT 11
DHT dht(DHTPIN, DHTTYPE);
void setup() {
  Serial.begin(9600);
  dht.begin();
}
void loop() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print("°C  | Humidity: ");
  Serial.print(humidity);
  Serial.println("%");
  delay(2000); // Wait 2 seconds
}
 
Package: 1XDHT11 Sensor