The AM2302 is a wired version of the DHT22, in a large plastic body. It is a low-cost basic digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the ambient air and spits a digital signal on the data pin (no analog input pin required). It is quite simple to use, but requires careful timing to enter the data. The only real disadvantage of this sensor is that you can only get new data once every 2 seconds, so when you use our library, sensor readings can have up to 2 seconds.

Simply connect the 3-5V red power supply, the yellow wire to the data input pin and the black wire to ground. Although it uses only one wire to send data, it is not compatible with Dallas One Wire! If you want several sensors, each one must have its own data pin.

Compared to DHT11, this sensor is more accurate and operates in a wider temperature/humidity range, but it is larger and more expensive.

There is a 5.1K resistance inside the sensor connecting VCC and DATA, so you do not need any additional pullup resistors.

Technical details

    Low cost
    Power supply 3 to 5V and I/O
    2.5mA max. operating current during conversion (when requesting data)
    Good for humidity readings of 0-100% with an accuracy of 2-5%.
    Good for temperature readings from -40 to 80°C with an accuracy of ±0.5°C
    Not more than 0.5 Hz sampling frequency (once every 2 seconds)
    Body dimensions 27mm x 59mm x 13.5mm (1.05" x 2.32" x 0.53")
    3 wires 23cm long (9")
    27mm wide x 58.75mm high x 13.30mm deep

Documentation

DHT11, DHT22 and AM2302 Sensors