HS-S71-L Resistive Film Pressure Sensor

The HS-S71-L Resistive Film Pressure Sensor is a pressure-sensing device based on the principle of resistance variation. It works using the piezoresistive effect: when pressure is applied to the sensor surface, the sensitive film layer undergoes mechanical deformation (compression or stretching), causing changes in the internal conductive pathways of the material. This results in a corresponding change in resistance. By measuring the resistance variation, the applied pressure can be detected and evaluated.

Features

• Resistive thin-film pressure sensing technology
• Digital signal output
• Compatible with Arduino and ESP32
• Supports 3.3V and 5V operating voltage
• PH2.0 3P connector interface
• LEGO-compatible mounting structure
• Simple wiring and easy integration

Pin Description

Specifications

Arduino UNO Example Code

void setup() {
  pinMode(2, INPUT);
  pinMode(3, OUTPUT);
}

void loop() {
  if (digitalRead(2) == LOW) {
    digitalWrite(3, HIGH);
  } else {
    digitalWrite(3, LOW);
  }
}

Working Principle

• When pressure is detected by the sensor, the LED connected to pin 3 turns ON.
• When no pressure is detected, the LED turns OFF.

ESP32 MicroPython Example Code

import machine

pin4 = machine.Pin(4, machine.Pin.IN)
pin12 = machine.Pin(12, machine.Pin.OUT)

while True:
    if pin4.value() == 0:
        pin12.value(1)
    else:
        pin12.value(0)

Required Components for Arduino UNO Testing

• UNO R3 PRO Development Board ×1
• R3P Expansion Board ×1
• USB Type-C Cable ×1
• HS-S71-L Pressure Sensor ×1
• HS-F08L LED Module ×1
• PH2.0 3P Cable ×2

Test Result

After uploading the sample program to the UNO R3 PRO development board and powering the circuit:

• The LED lights up when pressure is applied to the sensor.
• The LED turns off when no pressure is detected.

Applications

• Touch detection systems
• Pressure-triggered projects
• Smart interactive devices
• Educational STEM projects
• Robotics and automation