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Unread 05-10-2008, 17:41
Foster Foster is offline
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Re: Omni Vex code in easyc?

If you search for holonomic drive, you can find a number of posts about it.

Arthur Dutra wrote this code (and posted it) to support a holononmic drive. One joystick stick moves forward/back and side-side (and diagonally) for translation motion. The other joystic moves left/right to rotate, both can be moved at the same time.

The platform consists of four omni wheels mounted at 180 degrees from the next corner (ie two go "forward / backwards" two go "left / right"

Code is for the WPILibrary, so it should work fine with EasyC.

Let us know how you make out.

Code:
#include "API.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 ) ;
      }
}