Note: If you already configured your system and the sensor is not working all the time have a look at your cpu power saving settings.
In contrast to the Raspberry Pi unfortunately the Cubietruck is not as popular. Because of this there are much less instructions for how to use GPIO pins. Goal of this article is to measure the temperatur with a DS18B20 sensor. First of all you need the sensor (e.g. via Amazon or ebay). It has 3 wires: Ground (GND), 3,3 volt (VDD) and signal (DQ).