FSR402 Force Sensitive Resistor (0.5″ Circular) | Pro Tronix

Product Description

A highly responsive, low-profile force-sensing resistor (FSR) designed to measure physical pressure, squeezes, and weight changes in Arduino, ESP32, and custom wearable layouts. Featuring a 0.5-inch (12.7 mm) circular active sensing zone, the FSR402 acts as a variable dynamic resistor whose resistance decreases dramatically as force is applied to its active surface. When untouched, its standby resistance remains extremely high (greater than 10 M$\Omega$), dropping to a highly readable range under pressure (as low as 1 k$\Omega$ to 10 k$\Omega$ depending on the force). This flexible, ultra-thin polymer membrane sensor is the industry standard for creating robust touch interfaces, custom electronic musical triggers, robotic grip feedback mechanisms, and physical human-computer interaction modules.

Pinout / Layout Connections

The FSR402 is a passive, non-polarized two-terminal analog device, meaning connections can be wired in either direction:

• • Terminal 1: Connects to the system positive voltage reference (typically DC +5V or +3.3V).

  • Terminal 2: Connects to an analog input channel on your microcontroller.

  • Crucial Setup: To read this sensor as a clean analog voltage curve, you must build a voltage divider circuit. Connect a fixed pull-down resistor (typically $10\text{ k}\Omega$) between Terminal 2 and Ground (GND). This creates an analog voltage signal proportional to the applied force that can be read via any standard ADC.