The DHT22 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). Its 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.
Humidity measurement precision:±2%RH.
Temperature measurement precision:±0.5?.
No additional components.
Excellent long-term stability.
All calibration, digital output.
Long distance signal transmission.
Relative humidity and temperature measurement.