DHT22 Sensor for Temperature and Humidity
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.
DHT 22 output calibrated digital signal. It utilizes exclusive digital-signal-collecting-technique and humidity sensing technology, assuring its reliability and stability.Its sensing elements is connected with 8-bit single-chip computer.
Every sensor of this model is temperature compensated and calibrated in accurate calibration chamber and the calibration-coefficient is saved in type of program in OTP memory, when the sensor is detecting, it will cite coefficient from memory.
Small size & low consumption & long transmission distance(20 m) enable DHT 22 to be suited in all kinds of harsh application occasions.
this sensor is more precise, more accurate and works in a bigger range of temperature/humidity, but its larger and more expensive.
Comes with a 4.7K – 10K resistor, which you will want to use as a pullup from the data pin to VCC.