A control assembly provides autonomous control of various functions ofa grain cart and/or provides guidance to an operator of the grain cart duringtheunloading of a grain cart. The control assembly collects input from one ormore sensorsincluding a speed sensor to monitor speed of a PTO that drives the unloadingauger ofthe grain cart, a height sensor that measures the height of materialdischarged from thegrain cart into a receptacle such as a grain truck, and/or a boundary sensorsthatmeasure lateral position of the grain cart relative to the receptacle or graintruck. Basedon the input, the control assembly may vary the position of the discharge gateof thegrain cart, or provide guidance to the operator to steer and position thegrain cartrelative to an adjacent grain truck.
