The DHT22 is a basic, low-cost digital temperature and humidity sensor. Due to its low cost and ease of use, you’ll find project examples all over the web for these simple sensors.

Compared to the DHT11, this sensor is more precise, more accurate and works in a bigger range of temperature/humidity, at the cost of size and a slightly higher cost.

The DHT22 uses a capacitive humidity sensor and thermistor to measure the surrounding air, then provides that data via a digital output signal on the data pin. They’re easyto use, however, they require some careful timing to grab data.

You can only read data every 2 seconds, so when using something like the Adafruit library below, sensor readings can be up to 2 seconds old (not really a big deal for most projects).

Just connect the first pin on the left to 3-5V power, the second pin to your data input pin and the rightmost pin to GND. If you want multiple sensors, each one must have its own data pin (this isn’t OneWire folks!).

We have an Adafruit have a great guide with Arduino & CircuitPython code examples!

Comes with a 4.7K-10K resistor, for use as a pullup from the data pin to VCC.

Specifications

• 3-5V power and I/O
• 2.5mA max current use during conversion (while requesting data)
• 0-100% humidity readings with 2-5% accuracy
• -40 to 80C temperature readings 0.5C accuracy
• No more than 0.5 Hz sampling rate (once every 2 seconds)
• Body size 27mm x 59mm x 13.5mm
• 2.54mm/0.1″ pins (breadboard compatible)
• Weight: 2.4g