If you are wandering to build a device that detects temperature and humidity from the atmosphere, then This sensor is needed for you. 

The DHT22 Digital Temperature and Humidity Sensor Module AM2302 is a basic, low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air and spits out a digital signal on the data pin (no analog input pins needed).

It’s fairly simple to use but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, so when using our library, sensor readings can be up to 2 seconds old.

Features :

1. High precision
2. Capacitive type
3. Full range temperature compensated
4. Relative humidity and temperature measurement
5. Calibrated digital signal
6. Outstanding long-term stability
7. Extra components not needed
8. Long transmission distance
9. Low power consumption
10. 4 pins packaged and fully interchangeable

Package Includes :

1 x DHT22 Digital Temperature and Humidity Sensor Module AM2302