SoftPot Hookup Guide
jimblom SoftPot Overview
Softpots come in a variety of sizes. The SparkFun catalog sports 50mm, 200mm, and 500mm long softpot strips. You can also find circular, arc-shaped, or other uniquely-shaped softpots in the market.
The 50mm and 200mm softpot's feature a 10kΩ overall resistance between the outer-two terminals, while the larger 500mm softpot measures in at 20kΩ.
Placing your wiper at the base of the soft pot will effect a nearly 0Ω resistance between the middle pin and pin 1 (indicated by the arrow). When the wiper reaches the far end of the soft pot, the resistance will approach 10kΩ. And, if the wiper is in the middle, the resistance should be around 5kΩ.
The softpot is generally linear across the entire sensor area, so any math you'll do to determine a wiper's position should be relatively simple!