The DHT22 is a fundamental, minimal effort computerized temperature and mugginess sensor. It utilizes a capacitive stickiness sensor and a thermistor to gauge the encompassing air and releases an advanced signal on the input pin (no simple information pins required). Its genuinely easy to utilize, however, requires cautious planning to get information. The main genuine drawback of this sensor is you can just get new information from it once like clockwork, so when utilizing our library, sensor readings can be up to 2 seconds old. 

Just interface the primary stick on the left to 3-5V control, the second stick to your information input stick and the privilege most stick to ground. In spite of the fact that it utilizes a solitary wire to send information, it isn't Dallas One Wire perfect! On the off chance that you need various sensors, every one must have its own information stick! Arduino library with precedent code 

Contrasted with the DHT11, this sensor is more exact, more precise and works in a greater scope of temperature/moistness, yet its bigger and more costly 

Accompanies a 4.7K - 10K resistor, which you will need to use as a pull-up from the information stick to VCC.

Specialized Detail : 

Minimal effort 

3 to 5V power and I/O 

2.5mA max current use amid change (while asking for information) 

Useful for 0-100% mugginess readings with 2-5% precision 

Useful for - 40 to 80°C temperature readings ±0.5°C precision 

Close to 0.5 Hz testing rate (when like clockwork) 

Body measure 27mm x 59mm x 13.5mm (1.05" x 2.32" x 0.53") 

4 pins, 0.1" separating

Downloads:

1.  DHT22 datasheet
2. Arduino library and example code