Grove - Temperature & Humidity Sensor Pro (DHT22/AM2302)

Grove - DHT22 is a high-accuracy temperature and humidity sensor based on the DHT22 module (also known as AM2302 or RHT03). High-cost performance and high precision make it ideal for temperature and humidity monitoring of Arduino and Raspberry Pi, you can also use it to make a thermometer and hygrometer.

Features

• High accuracy and wide range of temperature and humidity measurements:
  - Humidity: 0 to 99.9 %RH with ±2% accuracy
  - Temperature: -40 to 80°C with an accuracy of ±0.5°C
• Ultra-low power consumption: standby current supply as low as 40uA
• Professional choice for relatively demanding applications: outperforms the basic DHT11
• Better compatibility: digital output of sensor data, I²C interface makes it more versatile
• Starter-friendly: Factory calibrated, easy to use, and backed by detailed wiki and documentation

Description

The DHT22 includes a capacitive humidity sensor and a high-precision temperature sensor. The range of humidity sensor is 0 to 99.9 %RH with ±2% accuracy while the temperature sensor ranges from -40 to 80℃ with ±0.5℃ accuracy. With the help of a built-in 8-bit microcontroller, the DHT22 converts the analog output of those two sensors to the digital signal, and outputs both temperature and humidity data via a single pin.

Compared with the DHT11, this product has higher precision and a wider measurement range, but the usage and code are almost the same. Simply put, if you need higher measurement accuracy, this product will be a better choice; if you need a higher price/performance ratio, then Grove - Temperature & Humidity Sensor (DHT11) may be more appropriate. The table lists below the main differences between the DHT22, DHt20 and DHT11:

	DHT22	DHT20	DHT11
Supply Voltage	DC: 3.0 - 6.0V	DC: 2.0 – 5.5V	DC: 3.3 – 5.5V
Measuring Range (Temperature)	-40 ~ + 80 ℃	-40 ~ + 80 ℃	-20 ~ + 60 ℃
Measuring Range (Humidity)	0 ~ 100% RH	0 ~ 100% RH	5 ~ 95% RH
Temperature Accuracy	± 0.5 ℃	± 0.5 ℃	± 1 ℃
Humidity Accuracy	± 2 % RH ( 25 ℃ )	± 3 % RH ( 25 ℃ )	± 5 % RH ( 25 ℃ )
Output Signal	I2C signal	I2C signal	1-Wire

DHT22 and DHT11 are both excellent temperatures and humidity sensors and they are widely used in Arduino and Raspberry Pi projects. However, from the comparison, the DHT22 outshines the DHT11 in every aspect from temperature range, temperature accuracy, humidity range to humidity accuracy. The only downside of the DHT22 is of course the slightly higher price but you are paying for the better specs.

So if you want a sensor with a wider range and accuracy, go for the DHT22. If not, the DHT11 should work fine for your projects as well.

All in all, DHT22 is an excellent low-cost temperature and humidity module, so we made this DHT22 breakout board with a Grove connector. Now it has even become more convenient to use. Just plug and play with your Seeeduino or Grove compatible shield. We have developed more than 400 Grove modules, covering a wide range of applications that can fulfill a variety of needs.