Abstract
This study aims to develop a computer-based seeding rate control using sensors for detecting the seeds dropped from the hopper and traveling speed and a personal computer to control the seed metering mechanism using pulse width modulation technique. As a first step, the rotational speed of the metering mechanism driven by a 12V DC motor was established and ranges from 7 to 87rpm using six different pulse frequencies and nine duty ratios ranging from 20 to 100 percent. The seed metering calibration curve of the seed metering mechanism under those speed ranges was also established. Finally equations to calculate the “On” and “Off” periods to be used for the control program were developed.
