SparkFun: 0.5" Force Sensitive Resistor

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The force-sensitive resistor.

Overview

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 FSR Integration Guide can be accessed here.

Bone Usage

The force-sensitive resistor works well when used with one of the BeagleBone's analog inputs. The images below outline how to hook it up. This schematic on the left is modified and originally from the SparkFun tutorial on the force-sensitive resistor. The example on the right outlines one way to hook-up the resistor to read values from the Bone.

Schematic Bone example

A 27kΩ resistor is used to connect the 3.3V source (pin 3) from the Bone to one pin of the force-sensitive resistor. Then, the other pin of the force-sensitive resistor is connected to ground (pin 1). An analog pin (AIN) on the Bone connects to the node containing both resistors, and values can be read off of that AIN. I'm using AIN5 (pin 36) to read values on the Bone.

Example Program

More to come...