The pressure sensor is an analog sensor that changes the electrical resistance when force, or pressure, is applied. Pressure sensors can be made from different kinds of materials from crystals to metals. This pressure sensor is made from a black plastic-like sheet called Velostat . When pressed or squished, it acts like a resistor to slow down electrical current going to a “pin” in a circuit.  A computer measures the resulting change in voltage and  converts it into an analog value from 0 to 1023.