This Adafruit_DHT_Driver code is deprecated and has been superseded by the Python library at https://github.com/adafruit/Adafruit_Python_DHT You can see the new library's C code for interfacing with the DHT sensors on either a Raspberry Pi or Beaglebone Black in the source/Raspberry_Pi or source/Beaglebone_Black directory of the new library. See more details on installing and using the library in the learning guide at: https://learn.adafruit.com/dht-humidity-sensing-on-raspberry-pi-with-gdocs-logging/overview