Measure Temperature and Humidity

Objective

Use the DHT22 sensor to measure temperature and humidity levels in an environment and display the results using an Arduino board.

Required Components

• DHT22 Sensor
• Arduino Board (e.g., Arduino Uno)
• Jumper wires
• Breadboard
• Arduino IDE (for programming)

Working Principle

The DHT22 sensor uses a capacitive humidity sensor and a thermistor to measure temperature and humidity. It outputs data in a digital signal to the Arduino for processing.

Circuit Diagram

Connect the sensor as follows:

• Connect VCC to the 5V pin on the Arduino.
• Connect GND to the GND pin on the Arduino.
• Connect the signal pin to digital pin 2 on the Arduino.

Arduino Code

#include 

#define DHTPIN 2  // DHT22 connected to digital pin 2
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

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

void loop() {
    float temperature = dht.readTemperature();
    float humidity = dht.readHumidity();

    if (isnan(temperature) || isnan(humidity)) {
        Serial.println("Failed to read from DHT sensor!");
        return;
    }

    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" °C");
    Serial.print("Humidity: ");
    Serial.print(humidity);
    Serial.println(" %");
    delay(2000);
}
            

Results

The serial monitor will display the temperature and humidity values, refreshed every 2 seconds.

Applications

• Weather monitoring stations
• Smart home climate control
• Industrial climate monitoring

Conclusion

The DHT22 sensor is an excellent tool for accurately measuring temperature and humidity, suitable for a wide range of applications.