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 get every 2 seconds. Instructions: imply connect the first pin on the left to 3-5V power, the second pin to your data input pin and the right most pin to ground
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/humidity, but its larger and more expensive
Comes with a 4.7K - 10K resistor, which you will want to use as a pullup from the data pin to VCC.
Arduino library and example code