A sensor assembly includes a sensor in the form of a microwave radar device to dispense microwaves in an area where seed or other particulate material is to be sensed. This may be a seed tube of a row unit. The microwaves of the radar provide an accurate determination if a seed or other particulate material has passed through the field of vision of the sensor to provide an accurate sensing of a seed event. This information can be used to determine the rate of planting, skips, doubles, as well as any other information related to the passing of a seed or other particulate material.