The DHT22 is a basic digital temperature and humidity sensor. The sensor uses the same internals as the AM2302, but sits in a much more compact, breadboard friendly package. 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. The sensor is accurate to +/- 0.5°C and +/- 2% relative humidity. This version is breadboard compatible and works well with the Arduino, Raspberry Pi, and just about anything else with a digital I/O pin available.

We recommend a 5.1K Ohm pull up resistor between the power and output line on this sensor to ensure nice, stable communication.