A Note about connections

In some cases the DHT sensors might not receive enough power from the breakout board or ribbon cables. You may test to see if the sensor is getting power and delivering information by running the DHTXXD program directly. From the directory you compiled it in, run

./DHTXXD -g17

where -g## is the BCM pin 17 for the device, and you should return some data.

If you get the result

Your device is not communicating and you may need to change how it is hooked up. You may need to bypass the ribbon cable, or use another +3.3v power source. Note that devices like DHT22 and DHT11 require 2.5mA max current to poll data.