Feeling Force with an FSR

Table of Contents

1. Introduction
2. Assemble the Parts
3. Configure the Radio
4. Wire up the Circuit
5. Use it!

1) Introduction

As opposed to a simple push button, force sensitive resistors (FSR’s for short) can sense how hard a user is pressing down. The resistance across the two leads on an FSR varies based on how much pressure is on the pad. With no pressure, there’s no continuity between the two leads. When you push softly, a connection is made between the two leads with some resistance. As you start pushing harder, the resistance drops.

By connecting the FSR to one of the two analog inputs on an XBee, we can create a wireless force sensor. This guide will walk you through how to configure and wire up an 802.15.4 XBee radio (Series 1) to read and transmit the levels from an FSR.