DHT22/AM2302 Digital Temperature and Humidity Sensor

The DHT22 is a basic, low-cost digital temperature and humidity sensor. 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). It's 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, so when using our library, sensor readings can be up to 2 seconds old.

Simply connect the first pin on the left to 3-5V power, the second pin to your data input pin, and the rightmost 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.

This sensor has a fully calibrated output. One of its features is the ability to measure temperature from minus 40 to plus 80 degrees Celsius with a resolution of 0.1 and an accuracy of 0.5 degrees, and measure humidity from 0 to 100 percent with a resolution of 0.1 and an accuracy of 2 percent. This sensor quickly delivers calibrated data due to its internal microcontroller system and OTP memory.

Specificatoins of DHT22/AM2302 Digital Temperature and Humidity Sensor:

• Low cost
• 3 to 5V power and I/O
• 2.5mA max current use during conversion (while requesting data)
• Good for 0-100% humidity readings with 2-5% accuracy
• Good for -40 to 80°C temperature readings ±0.5°C accuracy
• No more than 0.5 Hz sampling rate (once every 2 seconds)
• Body size 27mm x 59mm x 13.5mm (1.05" x 2.32" x 0.53")
• 4 pins, 0.1" spacing
• Weight (just the DHT22): 2.4g

Extra Notes:

Attention:

1. Do not use this product in cases where the failure of the sensor causes an accident.

2. The soldering temperature should be below 260 degrees Celsius.

3. Do not use this sensor in places with high humidity.

4. It is recommended to place the sensor at a suitable distance from other electronic components as far as possible so that it is not affected by the heat generated by the adjacent components.

5. Too much contact with strong light sources and ultraviolet light affects the performance of this sensor.

Applications:

Monitoring the temperature and humidity of the environment

Greenhouses