DHT22 Temperature and Humidity Sensor

Description

This is a very popular, low cost digital temperature and humidity sensor (also known as RHT03). It uses a capacitive humidity sensor, and a thermistor to measure the surrounding air temperature. The result is available via 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. But, for most applications this is not an issue at all.

Simply connect the first pin on the left to 3-5V power, the second pin to your data input pin and the right most pin to ground. Although it uses a single-wire to send data it is not Dallas One Wire compatible! If you want multiple sensors, each one must have its own data pin!

The DHT11 is a low cost version of this sensor. Compared to the DHT11, this sensor is more precise, more accurate and works in a wider temperature and humidity range.

There are many resources on the internet describing how to use it with Arduino, AVR, PIC and other embedded platforms.

Specifications

• 3.3V to 6V Operating Voltage
• 1-1.5mA measuring current
• 40-50 uA standby current
• Humidity from 0-100% RH
• -40 – 80 degrees C temperature range
• +-2% RH accuracy
• +-0.5 degrees C

Using this sensor with a Controller board

We stock a wide range of embedded Single Board Computers (Arduino, PIC Microchip SBC…) that can be used together with this sensor. Seeing that this sensors works with a wide operating voltage, it is compatible with any of our 3.3V and 5V boards. See the Boards section of our menu at the top of this page (or use search box) for our full range of SBC Boards. Following are some lists (created by search terms) of compatible accessories.

• 5V SBC Boards (search for “5v sbc”)
• 3.3V SBC Boards (search for “3.3v sbc”)
• Dual voltage 5V and 3.3V SBC Boards (search for “5v/3.3v sbc board”)
• Modtronix SBC Boards (search for “modtronix sbc”)
• Arduino Main SBC Boards (search for “arduino main board”)
• ….. For other lists, use search box on the top of this page!

Documentation, Sample Code and Resources

• The product datasheet in PDF format is available here.
• To post a question, or share code, see our user forum.

What is included

• 1 x DHT22 Temperature and Humidity Sensor