Description
A force sensitive resistor (FSR) is a type of resistor that changes its resistance based on the amount of pressure or force applied to it. FSRs are made of a thin, flexible material that changes its resistance when pressure is applied to it. As pressure is increased on the pad, the resistance across the two pins drops. The detection range is roughly between 0.04 and 4.5lbs, but are generally used to detect interaction (touch pads, inputs, etc.) and are not an ideal method of measuring the force applied.
FSRs are often used in conjunction with a microcontroller, which can measure the resistance of the FSR and interpret it as a specific pressure or force. The resistance of the FSR can be measured using a voltage divider circuit, in which the FSR is placed in series with a fixed resistor. The voltage across the FSR is then measured and used to calculate its resistance.