Auto Bed Leveling Solutions

[Roxy]

Yes, expanding the Gcodes M500, M501 and M502 commands and save, restore and load the Bed Level Correction Matrix from EEPROM are a solution to me, but how to do this?

In configurationstore.cpp there are 3 functions: void Config_StoreSettings(), void Config_PrintSettings(), void Config_RetrieveSettings()

In the store function... I would change:

EEPROM_WRITE_VAR(i,zprobe_zoffset);

to

EEPROM_WRITE_VAR(i,zprobe_zoffset);

EEPROM_WRITE_VAR(i,plan_bed_level_matrix[0][0]);
EEPROM_WRITE_VAR(i,plan_bed_level_matrix[0][1]);
EEPROM_WRITE_VAR(i,plan_bed_level_matrix[0][2]);

EEPROM_WRITE_VAR(i, plan_bed_level_matrix[1][0] );
EEPROM_WRITE_VAR(i, plan_bed_level_matrix[1][1] );
EEPROM_WRITE_VAR(i, plan_bed_level_matrix[1][2]);

EEPROM_WRITE_VAR(i, plan_bed_level_matrix[2][0] );
EEPROM_WRITE_VAR(i, plan_bed_level_matrix[2][1] );
EEPROM_WRITE_VAR(i, plan_bed_level_matrix[2][2] );

Corresponding changes would need to be made to the Config and Retrieve functions.

Can you give me some clues on Marlin code to find the function where as You said: "it just does a matrix multiply of the coordinate and the correction matrix."

Thanks

The matrix name with the correction matrix is called: plan_bed_level_matrix

You can find references to it in Marlin_main.cpp, Planner.cpp and Planner.h The Planner code is where Marlin 'Plans' its moves. That is where the coordinates are actually 'corrected'. It does this by doing: apply_rotation_xyz(plan_bed_level_matrix, x, y, z);

This function is defined in vector_3.cpp It looks like this:


void vector_3::apply_rotation(matrix_3x3 matrix)
{
float resultX = x * matrix.matrix[3*0+0] + y * matrix.matrix[3*1+0] + z * matrix.matrix[3*2+0];
float resultY = x * matrix.matrix[3*0+1] + y * matrix.matrix[3*1+1] + z * matrix.matrix[3*2+1];
float resultZ = x * matrix.matrix[3*0+2] + y * matrix.matrix[3*1+2] + z * matrix.matrix[3*2+2];

x = resultX;
y = resultY;
z = resultZ;
}

That would be a [1x3] matrix multiplied by a [3x3] matrix. [x,y,z] * [bed level correction matrix]