DHT22 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 programme in OTP memory, when the sensor is detecting, it will cite coefficient from memory.

Small size & low consumption & long transmission distance(20m) enable DHT22 to be suited in all kinds of harsh application occasions.

Compared to the DHT11, it has Higher Temperature and Humidity measurement Range, Lower Measurement Resolution, greater Long-term stability, but also comes at a higher price.

Data sent by DHT22 is comprised of integral and decimal part, the following is the formula for data. DHT22 send out higher data bit firstly!

DATA = 8 bit integral RH data+8 bit decimal RH data+8 bit integral T data+8 bit decimal T data+8 bit check-sum If the data transmission is right, check-sum should be the last 8 bit of “8 bit integral RH data+8 bit decimal RH data+8 bit integral T data+8 bit decimal T data”.

This module makes is easy to connect the DHT22 sensor to a microcontroller as includes the pull up resistor required to use the sensor. Only three connections are required to be made to use the sensor – VCC, GND and Output.

Features:

• Full range temperature compensated

• Calibrated digital signal

• Supports one-wire interface

• Input Voltage: 3.3~6V

• Measurement Range: 0-100%RH, -40~80℃

• Accuracy: Humidity ±2%RH, Temperature ±0.5℃

• Resolution: Humidity 0.1%RH, Temperature 0.1℃

• Pin Definition: GND,VCC,Signal

Applications:

1. Temperature and Humidity measurement

2. Local Weather station

3. Automatic climate control

4. Environment monitoring