Marlin firmware fork for MakerFarm i3v w/ auto bed level & Roxy's enhancements

[Roxy]

Dacb: Random new topic here: You modified the code to allocate space this way:
(I might have already added this code to your branch of the Marlin tree... But I could not Sync it)

// "A" matrix of the linear system of equations
double* eqnAMatrix = (double*)malloc(sizeof(double) * (n_points*n_points*3));
// "B" vector of Z points
double* eqnBVector = (double*)malloc(sizeof(double) * (n_points*n_points))

This really is a better way of doing it than assumming the stack is deep enough to handle those large arrays. But we probably should check that the memory was available on the heap. We might want to add right after the malloc()'s something like:

if ( eqnAMatrix==NULL || eqnBVector==NULL) {
            SERIAL_PROTOCOLPGM("?Memory not available for Auto Bed Leveling.\n");
            if (eqnAVector)
                 free(eqnAVector);
            if (eqnBVector)
                 free(eqnBVector);
            break;
}

and the memory isn't free()'ed at the end. At some point, the Arduino board won't be able to do Auto Bed Leveling any more!

#endif  // ORIGIN_FRONT_RIGHT
}
            set_bed_level_equation_lsq(plane_equation_coefficients);

            free(plane_equation_coefficients);
            free(eqnAVector);
            free(eqnBVector);
#else // AUTO_BED_LEVELING_GRID not defined

Mean while.... I've got my post processing script for Slic3r finding the print's size and modifying the G29 in the GCode file. I guess I'll use F, B, L, R for right now... But I think my vote is for using XMIN, YMIN, XMAX and YMAX.