Hello, Mora. I tried your library and found that code does not works properly all the time.
After system was powered up, few readings is OK and after that readFloatData() and readRawData() returns error (on my MSP430G2553 Launch pad).
I fixed this problem and also added two classes which buffers data from DHT22 and saves them in the internal memory. So, when you want get data faster than 1 time per 2 seconds (for DHT22) data will be returned from internal memory.
How can I send this fixes to you? Do you want them?