Disclosed herein is a shredder having a throat for receiving at least one article to be shredded therethrough and a shredder mechanism received in a shredder housing which is driven to shred the at least one article fed therein. At least one light-emitting diode (LED) acts as a sensor by emitting and detecting radiation when operated in a forward-biased and reverse-biased direction. The LED(s) may be used to detect the presence of the at least one article in the throat or an amount of shredded particles in a bin. The LED(s) communicate with a controller to operate the shredder mechanism. The controller may also calibrate an intensity of the radiation to or within a predetermined amount above a minimum level in order to reduce wear and run-on conditions.