Designing car backseat table

This post is about use of servo motor in Car backseat tray system.  Servo motor :                                     Servo motor is a dc motor with a derive circuit and position sensor for precise movements. position sensor used in servo motor is normally potentiometer attached to gears of motor. Derive circuit typically consists of  pulse width modulation to voltage converter feedback from potentiometer supply voltages Feedback from position sensor is compared with converted voltage and resulted output is used to correct position of motor until both signals are equal. Servo motor will maintain its position and resist  to any external change as long as modulated pulse is present at control wire of motor. Control signal :                               control signal is most complex signal out of three signal required to operate DC Servo motor . Other two signals are 0 v and 5 volts out of battery. To generate control signal we are using Pic 16f1789 micro-controller

Before installing micro controller to operate car backseat table read previous posts about how to install mechanical parts, installing dc motor and position sensors First of all select any  micro-controller   which is available and have external interrupts. I am using PIC-16f1789 in car backseat tray table Identify signals to operate the system To operate Car back seat table using micro-controller we need 3 signals for each table. One signal from open and close command to each table Detect open position of each table Detect close position of each table Here we are operating two tables so we need total six signals which are connected to port A through current limiting resistors(value of which depends on device type, specified on datasheet of I.C. you  are using). Electrical specifications for PIC 16f1789 Port A is used for interrupt input.Connections will be as follows. port A,1 connect with open/close button for table 1. port A,2 connect with open/close button