The lie detector uses an effect known as galvanic skin response. As a person becomes nervous - for example, when telling a lie - his or her skin resistance decreases. We can measure this resistance using an analog input and use an LED and buzzer to indicate an untruth.
Web Post Requirements (50 points)
Your body acts as a resistor between two paper clips The galvanic skin resistance drops for most people when they lie
You have to "tune" the lie detector (turn the potentiometer knob to green while the person holds the two paper clips