Air seeder blockage monitoring system

Abstract

A seed blockage monitoring system employs a flexible, generally flat piezoelectric seed sensor element inserted at an acute angle of about 13 degrees into a seed flow path so that a portion of seeds traveling in the seed flow path strike the seed sensor element, preventing damage to the seeds and maintaining forward momentum of all seeds in the seed flow path. In order to provide flexibility in monitoring seeds of different types and to increase the data rate that information can be obtained from numerous multiple seed sensor elements, the use of a one-shot to temporarily store a seed detection signal and serial sampling of the temporarily stored signals from the sensors as in the prior art is avoided. Instead, a comparator that includes a diode in a feedback loop so as to function as a latch is used in conjunction with a serial shift register that has parallel data input lines. This enables the microprocessor to monitor outputs from one or more sensor elements, or a digital representation thereof, at a higher rate than attainable in the prior art seed blockage monitors. As a result of the increased rate at which information can be obtained from the seed sensor elements, the microprocessor can not only provide seed blockage data but can also provide relative flow data for the various monitored seed flow paths and compute an overall seeding rate.