The AM2320 sensor is made of two parts, the capacitive humidity sensor and the thermistor. There is also a basic chip inside that converts the analog signal to a digital signal with the temperature and the humidity.The digital signal is easy to read using a microcontroller. It has an I2C interface.  You can buy it cheap on the internet.  It has 3% humidity accuracy and 0.5C temperature accuracy. 

Specifications AM2320

  • Low cost
  • 5V power and I/O
  • 20% to 80% humidity reading with 3% accuracy
  • 0°C to 50°C temparature reading with 0.5°C accuracy.

The AM2320 has four pins to connect to a microocntroller:

pin  Signal 
 1  VCC 5V
 2  SDA
 3  Ground
 4  SCL