DHT22 Temperature and Humidity Sensor

Description

PLEASE note, this is an authentic DHT22 sensor. Nearly all cheap DHT22 sensors available on eBay and similar sites are clone versions with inferior quality and accuracy!

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 temperature. The result is available via 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 only real downside of this sensor is you can only get new data from it once every 2 seconds. But, for most applications this is not an issue at all.

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.

The DHT11 is a low cost version of this sensor. Compared to the DHT11, this sensor is more precise, more accurate and works in a wider temperature and humidity range.

There are many resources on the internet describing how to use it with Arduino, AVR, PIC and other embedded platforms.

Specifications

• 3.3V to 6V Operating Voltage
• 2.5mA max current use during conversion (while requesting data)
• 40-50 uA standby current
• Humidity from 0-100% RH
• Temperature Range -40 to 80 degrees C
• +-2% to +-5% RH(Relative Humidity) accuracy at 0-100% RH
• +-0.5 degrees C accuracy at -40 to 80°C
• 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

Specs and Docs

• PDF DatasheetPDF Datasheet:
  99tech.com.au/m/sens-dht22_datasheet.pdf
• Comparison between DHT vs SHT vs DS18B20 vs LM35 Temperature and Humidity SensorsComparison between DHT vs SHT vs DS18B20 vs LM35 Temperature and Humidity Sensors:
  99tech.com.au/sensor-information/dht-vs-sht-vs-ds18b20-vs-lm35