SparkFun: 0.5" Force Sensitive Resistor
The SparkFun 0.5" Force Sensitive Resistor varies its resistance based on the amount of force applied to it. The larger the force, the lower the resistance of the device. When no force is being applied, the resistance is larger than 1MΩ. Like a regular resistor, it only has two leads.
The force-sensitive resistor works well when used with the BeagleBone's analog inputs. The schematic below outlines how to hook it up. This image is modified and originally from the SparkFun tutorial on the force-sensitive resistor.
A 27kΩ resistor is used to connect the 3.3V source from the Bone to one pin of the force-sensitive resistor. Then, the other pin of the force-sensitive resistor is connected to ground. An analog pin (AIN) on the Bone connects between the two resistors, and values can be read off of that AIN.
More to come...