DHT22 Temperature and Humidity Module

A straightforward, inexpensive digital temperature and humidity sensor is the DHT22. It measures the humidity and temperature of the air around it using a thermistor and a capacitive humidity sensor, and it outputs a digital signal on the data pin without the requirement for analogue input pins. Although it is reasonably straightforward to use, data collection requires precise timing. The only significant drawback of this sensor is that since it only provides updated information once every two seconds, readings may be as much as two seconds old.

Just attach the leftmost pin to 3-5V power, the middle pin to your data input pin, and the rightmost pin to ground. It is not compatible with the Dallas One cable, even though it uses a single cable to deliver data! Multiple sensors are required, and each one has its own data pin.

Specifications

•        Power supply: 3.3V – 6V DC
•        Output signal: single-bus
•        Sensing element: polymer humidity capacitor & DS18B20
•        Measuring range: humidity 0-100% RH / temperature -40°C – 80°C
•        Accuracy: humidity ±2% / temperature ±0.2°C
•        Sensing period: ~2s
•        Module size: 18.3mmx11mmx48mm
•        Module Weight: 5g.