Honeywell HumidIconTM Digital Humidity/Temperature Sensors: 
HIH6130/6131 and 6120/6121 Series is a digital output-type relative humidity (RH) 
and temperature sensor combined in the same package. The library uses I2C to 
connect to the sensor (see the Wire library). SPI can also be used, but is not 
implemented in this library.

The library consists of 2 classes (actually 2 libraries):

HIH61XX: Use this one if you just want to get the humidity/temperature.
HIH61XXCommander: Use this one if you want to enter command mode and change (or 
even just read) some of the EEPROM registers. 

If you have multiple devices connected to the I2C bus, remember that this device 
screws up the bus when it is not powered. One solution is to keep the device 
powered all the time. Another possible solution is to add an analog switch to 
physically disconnect the GND line or the SDA line to the device.

This library has been tested, but might still contain bugs, so please be careful.

Bugs, suggestions, comments are always welcome