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DHT11 Temperature and Humidity Meter

A starter project that measures the room's temperature and humidity with a DHT11 sensor and writes the values to the Arduino IDE's Serial Monitor once a second. Before uploading the code, install the DHTlib library in the Arduino IDE.

What you need

• 1 × Arduino Uno R3
• 1 × DHT11 Temperature/Humidity Sensor
• 3 × Jumper Wire - Male/Female

Wiring steps

1. 1

   Power the sensor

   

   Plug a red jumper wire into the 5V pin on the Arduino's POWER header. Connect its other end to the top pin of the DHT11 module, marked + (VCC).

2. 2

   Connect the data line

   

   Plug a blue jumper wire into the Arduino's digital pin 2. Connect its other end to the middle data (DATA) pin of the DHT11 module. The code reads the sensor on this pin.

3. 3

   Ground (GND) connection

   

   Plug a black jumper wire into the GND pin on the Arduino's digital header, next to pin 13. Connect its other end to the bottom pin of the DHT11 module, marked −. That completes all three of the sensor's connections.

Arduino sketch

#include <dht.h>

dht DHT;

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

void loop() {
  // DHT11 sensörünü 2 numaralı pinden okuyoruz
  int chk = DHT.read11(2);

  // Sıcaklık verisini Serial Monitor'e yazdır
  Serial.print("Temp: ");
  Serial.print(DHT.temperature);
  Serial.print(" °C\t"); // '\t' ile araya bir tab boşluğu ekliyoruz

  // Nem verisini Serial Monitor'e yazdır
  Serial.print("Humidity: ");
  Serial.print(DHT.humidity);
  Serial.println(" %"); // Satırı bitirip bir alt satıra geçmek için println kullanıyoruz

  delay(1000);
}

What the Serial Monitor shows

Temp: 24.00 °C    Humidity: 45.00 %
Temp: 24.00 °C    Humidity: 45.00 %