FSR-400 Pressure Sensor EN

Overview

FSR (Force Sensing Resistor) is a sensor that detects pressure, and its resistance changes when force or pressure is applied.

This guide introduces a simple way to measure pressure using Arduino.

Working Principle

The sensor is made of multiple layers stacked together. When pressure is applied, the contact area between the layers increases, and the resistance decreases.

By connecting the FSR in series with a resistor, the change in resistance is measured through voltage division, and the pressure is read via an Arduino analog pin.

Specifications

Detection Range	0.1 ~ 100N (may vary depending on the model)
Size	7.6 x 38 mm
Diameter	5.08 mm

Example Usage

This example demonstrates how to observe the change in voltage when the FSR-400 pressure sensor is pressed, using the serial monitor.

A pull-down resistor circuit is set up to prevent noise and for voltage division.

If the resistor value is too large, the sensitivity may decrease. If it's too small, the sensitivity becomes too high and can strain the circuit, so it's best to use the appropriate value. In this example, a 10kΩ resistor is used.

Circuit Configuration

The FSR-400 sensor has no polarity, so either pin can be used.

Example Code

const int fsr = A0; // FSR sensor connected to analog pin

void setup() {
  Serial.begin(9600); // Start serial communication
}

void loop() {
  int val = analogRead(fsr); // Read analog value from FSR
  Serial.print("FSR Reading: "); // Output message
  Serial.println(val); // Print the value

  delay(500); // Wait for 0.5 seconds
}

Execution Result

When the sensor is not pressed, the value is 0, and as pressure is applied to the sensor, the voltage value increases.