pic: it's a Vex Holonomic Drive!

[artdutra04]

As requested, here is the code from EasyC ver 2.0 that I used for my Vex Holonomic Drive robot. The main drive controls are relative holonomic drive, which is relative to the current position of the robot. So if you push the left joystick to the left, the robot will go to its left. The code works well, and for a lot of people who I let drive this, it was a lot easiar for them to control than the tank drive on my Triple Play / Space Elevator vex robot.

Here's the code:

#include "Main.h"

void main ( void )
{
int LF; // Left Front
int RF; // Right Front
int LR; // Left Rear
int RR; // Right Rear
int leftx;
int lefty;
int rightx;
int spin;
      while ( 1 )
      {
            // Get Data 
            leftx = GetRxInput ( 1 , 4 ) ; // Left Joystick, X Axis
            lefty = GetRxInput ( 1 , 3 ) ; // Left Joystick, Y Axis
            rightx = GetRxInput ( 1 , 1 ) ; // Right Joystick, X Axis
            // Half the input signal (so code does not overflow past 255)
            leftx = leftx / 2 ;
            lefty = lefty / 2 ;
            spin = rightx / 2 ;
            // Drive Code Algorithim
            LF = RR = lefty - leftx + 127 ;
            RF = LR = 255 - lefty - leftx ;
            RR = 255 - RR ; // Reverse Direction of RR motor
            LR = 255 - LR ; // Reverse Direction of LR motor
            // Spin Code Algorithim
            RF = RF - spin + 63 ;
            RR = RR - spin + 63 ;
            LF = LF - spin + 63 ;
            LR = LR - spin + 63 ;
            // Code overflow prevention
            if ( LF < 0 )
            {
                  LF = 0 ;
            }
            else if ( LF > 255 )
            {
                  LF = 255 ;
            }
            if ( RF < 0 )
            {
                  RF = 0 ;
            }
            else if ( RF > 255 )
            {
                  RF = 255 ;
            }
            if ( RR < 0 )
            {
                  RR = 0 ;
            }
            else if ( RR > 255 )
            {
                  RR = 255 ;
            }
            if ( LR < 0 )
            {
                  LR = 0 ;
            }
            else if ( LR > 255 )
            {
                  LR = 255 ;
            }
            // Set Motors
            SetMotor ( 1 , RF ) ;
            SetMotor ( 2 , LF ) ;
            SetMotor ( 3 , LR ) ;
            SetMotor ( 4 , RR ) ;
      }
}

I may resurrect this robot (at least the drive platform) at some point over this summer and utilize the gyro from the FIRST KOP to make the robot a true absolute holonomic drive. But that will be added to my list of designs and ideas to try out, now that I have stock-piled enough Vex stuff in my fallout shelter to last through seven world wars.

I'm dead serious too - I really do have like $2000 worth of Vex stuff.