DHT22 temperature and humidity sensor

The DHT22 temperature and humidity sensor is a low-cost high precision humidity and temperature sensor with a single wire digital interface, meaning many of these sensors can be strung (daisy chained) together from one digital pin.

The sensor is pre-calibrated and doesn't require extra components so you can get right to measuring relative humidity and temperature.

DHT22 temperature and humidity sensor Features:
3.3 - 6 V Input
1-1.5 mA measuring current
40-50 uA standby current
Humidity from 0 - 100 % RH
-40 - 80 degrees C temperature range
+- 2 % RH accuracy
+- 0.5 degrees C
20 m max wire length

Sketch example

/* DHT11/ DHT22 Sensor Temperature and Humidity Tutorial
 * Program made by Dejan Nedelkovski,
 * www.HowToMechatronics.com 
 */
/*
 * You can find the DHT Library from Arduino official website
 * http://playground.arduino.cc/Main/DHTLib
 */
 
#include <dht.h>
#define dataPin 8 // Defines pin number to which the sensor is connected
dht DHT; // Creats a DHT object
void setup() {
 Serial.begin(9600);
}
void loop() {
 int readData = DHT.read22(dataPin); // Reads the data from the sensor
 float t = DHT.temperature; // Gets the values of the temperature
 float h = DHT.humidity; // Gets the values of the humidity
 
 // Printing the results on the serial monitor
 Serial.print("Temperature = ");
 Serial.print(t);
 Serial.print(" *C ");
 Serial.print(" Humidity = ");
 Serial.print(h);
 Serial.println(" % ");
 
 delay(2000); // Delays 2 secods, as the DHT22 sampling rate is 0.5Hz
}