Force Sensitive Resistors

heater pad

Overview

Force-Sensitive-Resistors (FSR) are specialised sensors that allow you to detect physical pressure, squeezing and weight. They are simple to use and they change the resistive value (in ohms Ω) depending on how much it’s pressed. In hackSpace we have two types: a square 1.75×1.5 inches and a round one 0.5 inches both sensitive in range of 100g-10kg.

However, the sensor is rarely accurate as the tolerance is in-between 10%. So basically when you use FSR’s you should only expect to get ranges of response, which are close to the value you are looking for. While FSRs can detect weight, they’re a bad choice for detecting exactly how many pounds of weight are on them.

FSR has two connections positive and negative and it doesn’t really matter which way around the sensor is to your microcontroller. However the best way to connect to these is to simply plug them into a breadboard or use a clamp-style connector like alligator clips, female header, or a terminal block.

It is possible to solder onto the tabs but you must be very fast because if your iron is not good quality or you dally even a few seconds, you will melt the plastic and ruin the Force resistor. Don’t attempt to solder directly to your FSR unless you are absolutely sure you have the skills to do so.

 

Health & safety

  • Ensure you are familiar with all H&S rules that apply to the environment you are working in.
  • Identify where first aid can be found in your work space
  • Keep all components dry and free from liquid spillages
  • To avoid static, make sure your work surface is sufficiently earthed