This product is very special since it is a sensor that works well with temperature and humidity, yet still is available in a low suitable price. It measures the air through a thermistor and a capacitive humidity sensor.
It’s very user friendly, yet you have to be careful in the timing for grabbing data. Note that: New data can be obtained from our library every 2 seconds.
Compared to the DHT22, this sensor is less precise, less accurate and works in a smaller range of temperature/humidity, but its smaller and less expensive
Comes with a 4.7K or 10K resistor, which you will want to use as a pullup from the data pin to VCC.
We have the DHT11 datasheet but its in chinese so its not easy to understand. However, the sensor protocol and timing is similar to the DHT22 so check out the DHT22 datasheet for more information
Arduino library and example code