GSR Based Lie Detector Device

The GSR Based Lie Detector Device operates by measuring changes in human skin electrical conductivity, known as Galvanic Skin Response (GSR). The core of the circuit is built around an Arduino Uno connected to a GSR sensor, which typically uses two electrodes attached to a person's fingers. When an individual experiences physiological arousal, stress, or emotional stimuli—such as answering a question deceptively—their sweat glands become more active. This increase in moisture alters the electrical resistance of the skin. The GSR sensor detects this fluctuating resistance and outputs an analog voltage signal corresponding to the conductivity level. The Arduino board reads this analog signal through one of its input pins using an analog-to-digital converter. Inside the microcontroller, the code processes the incoming data stream to monitor baseline skin conductance and detect sudden peaks or shifts. If the measured conductance exceeds a predefined threshold, the Arduino triggers an output device, such as a buzzer or an LED indicator, to signal a potential deception event. A breadboard and jumper wires are used to distribute power from the Arduino and cleanly interconnect the sensor and indicators into a complete, portable monitoring circuit.