A weight pin for use with a stacked weight exercise machine includes a handle portion, and a shaft portion extending outwardly from the handle portion. The shaft portion is configured to be removably positioned adjacent to one or more weights of the exercise machine to selectively engage the one or more weights during use of the exercise machine. The weight pin also includes interrogation circuitry arranged relative to the handle portion, the interrogation circuitry configured to read information from the adjacent one or more weights.