Description
The DHT22 Temperature and Humidity Sensor 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 outputs a digital signal on the data pin. It's fairly simple to use, but requires careful timing to grab data. The only real downside of this sensor is that 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. We have written an Arduino library with example code.
Compared to the DHT11, this sensor is more precise, more accurate, and works in a bigger range of temperature and humidity — but it is larger and more expensive.
Comes with a 4.7K–10K resistor, which you will want to use as a pull-up from the data pin to VCC.
Technical Details
- 3 to 5V power and I/O
- 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
Downloads
