The objective of the research is to speed up the process of selecting the corn kernel from the design and automation of the separator screen with granulometric regulation. The process comprises five stages (mechanical design, machine development, electrical design of the system, calculation of the force of pneumatic cylinders and programming of the Programmable Logic Controller - PLC). With the design, it will be possible to choose the desired granulometry of the selected grain in an easy and accurate way, making use of modern control equipment. The control is in charge of a PLC, in a first version, together with a friendly graphical interface, the common mechanical aspect of a vibrating screen added to the movement control of the overlapping meshes achieves the variation of the selection diameter of the corn kernel, in addition to the speed control of the motor vibrators that will have an effect on the force exerted on the mobile tray. The simulation of efforts was performed with the help of inventor 2019 software. As a result, the optimization to be able to select the grains and homogenize their size is evident. In conclusion, this automation process helps to make the feeding of the birds more efficient by the variable granulometric selection of the corn, in addition the automation of the screen allowed to reduce the time in a ratio of 10 to 1.