The DHT22 is a basic, low-cost digital temperature and humidity sensor
uses a capacitive humidity sensor and a thermistor to measure the
surrounding air and spits out a digital signal on the data pin. It is
very simple to use with an Arduino...
The DHT22 is a basic, low-cost digital temperature and humidity sensor
uses a capacitive humidity sensor and a thermistor to measure the
surrounding air and spits out a digital signal on the data pin. It is
very simple to use with an Arduino or Raspberry Pi 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 a library,
sensor readings can be up to 2 seconds old.
Connect the first
pin on the left to a 3-5V power source, 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.
Compared
to the DHT11, this sensor is more precise, more accurate and works in a
bigger range of temperature/humidity, but it is larger and slightly
more expensive.
