Enhanced G29

- Adapted “Enhanced G29” code referred to in #1499 and posted at
[3dprintboard.com](http://3dprintboard.com/showthread.php?3105-Auto_Bed_
Leveling-Enhanced-G29-command)
- Compatible with current G29 while adding some new arguments
  - `V` sets the verbose level for serial out
  - `T` (or `V` > 2) send a Topology report to serial out
  - `E` works the same way as before
  - `P` works as before (source used `n` or `U`/`u`)
  - `L`, `R`, `B`, `F` work as before
- Still needs sanity checking for `LRBF`

Marlin/Marlin_main.cpp

@@ -1200,22 +1200,24 @@ static void retract_z_probe() {
     #endif
 }
 
+enum ProbeAction { ProbeEngageRetract, ProbeEngage, ProbeStay, ProbeRetract };
+
 /// Probe bed height at position (x,y), returns the measured z value
-static float probe_pt(float x, float y, float z_before, int retract_action=0) {
+static float probe_pt(float x, float y, float z_before, ProbeAction retract_action=ProbeEngageRetract) {
   // move to right place
   do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], z_before);
   do_blocking_move_to(x - X_PROBE_OFFSET_FROM_EXTRUDER, y - Y_PROBE_OFFSET_FROM_EXTRUDER, current_position[Z_AXIS]);
 
-#ifndef Z_PROBE_SLED
+  #ifndef Z_PROBE_SLED
-   if ((retract_action==0) || (retract_action==1)) 
+    if (retract_action == ProbeEngageRetract || retract_action == ProbeEngage) engage_z_probe();
-     engage_z_probe();   // Engage Z Servo endstop if available
+  #endif
-#endif // Z_PROBE_SLED
+
   run_z_probe();
   float measured_z = current_position[Z_AXIS];
-#ifndef Z_PROBE_SLED
+
-  if ((retract_action==0) || (retract_action==3)) 
+  #ifndef Z_PROBE_SLED
-     retract_z_probe();
+    if (retract_action == ProbeEngageRetract || retract_action == ProbeRetract) retract_z_probe();
-#endif // Z_PROBE_SLED
+  #endif
 
   SERIAL_PROTOCOLPGM(MSG_BED);
   SERIAL_PROTOCOLPGM(" x: ");
@@ -1376,6 +1378,11 @@ void refresh_cmd_timeout(void)
 #endif //FWRETRACT
 
 #ifdef Z_PROBE_SLED
+
+  #ifndef SLED_DOCKING_OFFSET
+    #define SLED_DOCKING_OFFSET 0
+  #endif
+
 //
 // Method to dock/undock a sled designed by Charles Bell.
 //
@@ -1719,25 +1726,96 @@ void process_commands()
       break;
 
 #ifdef ENABLE_AUTO_BED_LEVELING
-    case 29: // G29 Detailed Z-Probe, probes the bed at 3 or more points.
+
-    	     // Override probing area by providing [F]ront [B]ack [L]eft [R]ight Grid[P]oints values
-        {
     #if Z_MIN_PIN == -1
-            #error "You must have a Z_MIN endstop in order to enable Auto Bed Leveling feature!!! Z_MIN_PIN must point to a valid hardware pin."
+      #error "You must have a Z_MIN endstop in order to enable Auto Bed Leveling!!! Z_MIN_PIN must point to a valid hardware pin."
     #endif
 
-            // Prevent user from running a G29 without first homing in X and Y
+   /**
-            if (! (axis_known_position[X_AXIS] && axis_known_position[Y_AXIS]) )
+    * Enhanced G29 Auto Bed Leveling Probe Routine
+    * 
+    * Parameters With AUTO_BED_LEVELING_GRID:
+    *
+    *  P  Set the size of the grid that will be probed (P x P points).
+    *     Example: "G29 P4"
+    *
+    *  V  Set the verbose level (0-4). Example: "G29 V3"
+    *
+    *  T  Generate a Bed Topology Report. Example: "G29 P5 T" for a detailed report.
+    *     This is useful for manual bed leveling and finding flaws in the bed (to
+    *     assist with part placement).
+    *
+    *  F  Set the Front limit of the probing grid
+    *  B  Set the Back limit of the probing grid
+    *  L  Set the Left limit of the probing grid
+    *  R  Set the Right limit of the probing grid
+    *
+    * Global Parameters:
+    *
+    * E/e By default G29 engages / disengages the probe for each point.
+    *     Include "E" to engage and disengage the probe just once.
+    *     There's no extra effect if you have a fixed probe.
+    *     Usage: "G29 E" or "G29 e"
+    *
+    */
+
+    case 29: // G29 Detailed Z-Probe, probes the bed at 3 or more points.
     {
+      // Use one of these defines to specify the origin
+      // for a topographical map to be printed for your bed.
+      #define ORIGIN_BACK_LEFT   1
+      #define ORIGIN_FRONT_RIGHT 2
+      #define ORIGIN_BACK_RIGHT  3
+      #define ORIGIN_FRONT_LEFT  4
+      #define TOPO_ORIGIN        ORIGIN_FRONT_LEFT
+
+      // Prevent user from running a G29 without first homing in X and Y
+      if (!(axis_known_position[X_AXIS] && axis_known_position[Y_AXIS])) {
         LCD_MESSAGEPGM(MSG_POSITION_UNKNOWN);
         SERIAL_ECHO_START;
         SERIAL_ECHOLNPGM(MSG_POSITION_UNKNOWN);
         break; // abort G29, since we don't know where we are
       }
 
-#ifdef Z_PROBE_SLED
+      bool enhanced_g29 = code_seen('E') || code_seen('e');
-            dock_sled(false);
+
-#endif // Z_PROBE_SLED
+      #ifdef AUTO_BED_LEVELING_GRID
+
+        // Example Syntax:  G29 N4 V2 E T
+        int verbose_level = 1;
+
+        bool topo_flag = code_seen('T') || code_seen('t');
+
+        if (code_seen('V') || code_seen('v')) {
+          verbose_level = code_value();
+          if (verbose_level < 0 || verbose_level > 4) {
+            SERIAL_PROTOCOLPGM("?Verbose Level not plausible (0-4).\n");
+            break;
+          }
+          if (verbose_level > 0) {
+            SERIAL_PROTOCOLPGM("Enhanced G29 Auto_Bed_Leveling Code V1.25:\n");
+            SERIAL_PROTOCOLPGM("Full support at http://3dprintboard.com\n");
+            if (verbose_level > 2) topo_flag = true;
+          }
+        }
+
+        int auto_bed_leveling_grid_points = code_seen('P') ? code_value_long() : AUTO_BED_LEVELING_GRID_POINTS;
+        if (auto_bed_leveling_grid_points < 2 || auto_bed_leveling_grid_points > AUTO_BED_LEVELING_GRID_POINTS) {
+          SERIAL_PROTOCOLPGM("?Number of probed points not plausible (2 minimum).\n");
+          break;
+        }
+
+        int left_probe_bed_position = code_seen('L') ? code_value_long() : LEFT_PROBE_BED_POSITION;
+        int right_probe_bed_position = code_seen('R') ? code_value_long() : RIGHT_PROBE_BED_POSITION;
+        int back_probe_bed_position = code_seen('B') ? code_value_long() : BACK_PROBE_BED_POSITION;
+        int front_probe_bed_position = code_seen('F') ? code_value_long() : FRONT_PROBE_BED_POSITION;
+
+      #endif
+
+      #ifdef Z_PROBE_SLED
+        dock_sled(false); // engage (un-dock) the probe
+      #endif
+
       st_synchronize();
       // make sure the bed_level_rotation_matrix is identity or the planner will get it incorectly
       //vector_3 corrected_position = plan_get_position_mm();
@@ -1752,22 +1830,12 @@ void process_commands()
       setup_for_endstop_move();
 
       feedrate = homing_feedrate[Z_AXIS];
-#ifdef AUTO_BED_LEVELING_GRID
+
+      #ifdef AUTO_BED_LEVELING_GRID
         // probe at the points of a lattice grid
-            int left_probe_bed_position=LEFT_PROBE_BED_POSITION;
-            int right_probe_bed_position=RIGHT_PROBE_BED_POSITION;
-            int back_probe_bed_position=BACK_PROBE_BED_POSITION;
-            int front_probe_bed_position=FRONT_PROBE_BED_POSITION;
-            int auto_bed_leveling_grid_points=AUTO_BED_LEVELING_GRID_POINTS;
-            if (code_seen('L')) left_probe_bed_position=(int)code_value();
-            if (code_seen('R')) right_probe_bed_position=(int)code_value();
-            if (code_seen('B')) back_probe_bed_position=(int)code_value();
-            if (code_seen('F')) front_probe_bed_position=(int)code_value();
-            if (code_seen('P')) auto_bed_leveling_grid_points=(int)code_value();
-
-            int xGridSpacing = (right_probe_bed_position - left_probe_bed_position) / (auto_bed_leveling_grid_points-1);
-            int yGridSpacing = (back_probe_bed_position - front_probe_bed_position) / (auto_bed_leveling_grid_points-1);
 
+        int xGridSpacing = (right_probe_bed_position - left_probe_bed_position) / (auto_bed_leveling_grid_points - 1);
+        int yGridSpacing = (back_probe_bed_position - front_probe_bed_position) / (auto_bed_leveling_grid_points - 1);
 
         // solve the plane equation ax + by + d = z
         // A is the matrix with rows [x y 1] for all the probed points
@@ -1775,125 +1843,155 @@ void process_commands()
         // the normal vector to the plane is formed by the coefficients of the plane equation in the standard form, which is Vx*x+Vy*y+Vz*z+d = 0
         // so Vx = -a Vy = -b Vz = 1 (we want the vector facing towards positive Z
 
-            // "A" matrix of the linear system of equations
+        int abl2 = auto_bed_leveling_grid_points * auto_bed_leveling_grid_points;
-            double eqnAMatrix[auto_bed_leveling_grid_points*auto_bed_leveling_grid_points*3];
-
-            // "B" vector of Z points
-            double eqnBVector[auto_bed_leveling_grid_points*auto_bed_leveling_grid_points];
-
 
+        double eqnAMatrix[abl2 * 3], // "A" matrix of the linear system of equations
+               eqnBVector[abl2],     // "B" vector of Z points
+               mean = 0.0;
 
         int probePointCounter = 0;
         bool zig = true;
 
-            for (int yProbe=front_probe_bed_position; yProbe <= back_probe_bed_position; yProbe += yGridSpacing)
+        for (int yProbe = front_probe_bed_position; yProbe <= back_probe_bed_position; yProbe += yGridSpacing) {
-
-            {
           int xProbe, xInc;
+
           if (zig)
-              {
+            xProbe = left_probe_bed_position, xInc = xGridSpacing;
-                xProbe = left_probe_bed_position;
+          else
-                //xEnd = right_probe_bed_position;
+            xProbe = right_probe_bed_position, xInc = -xGridSpacing;
-                xInc = xGridSpacing;
-                zig = false;
-              } else // zag
-              {
-                xProbe = right_probe_bed_position;
-                //xEnd = left_probe_bed_position;
-                xInc = -xGridSpacing;
-                zig = true;
-              }
 
-              for (int xCount=0; xCount < auto_bed_leveling_grid_points; xCount++)
+          // If topo_flag is set then don't zig-zag. Just scan in one direction.
-              {
+          // This gets the probe points in more readable order.
-                float z_before;
+          if (!topo_flag) zig = !zig;
-                if (probePointCounter == 0)
+
-                {
+          for (int xCount = 0; xCount < auto_bed_leveling_grid_points; xCount++) {
-                  // raise before probing
-                  z_before = Z_RAISE_BEFORE_PROBING;
-                } else
-                {
             // raise extruder
-                  z_before = current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS;
+            float z_before = probePointCounter == 0 ? Z_RAISE_BEFORE_PROBING : current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS,
-                }
+                  measured_z;
 
-                float measured_z;
+            // Enhanced G29 - Do not retract servo between probes
-                //Enhanced G29 - Do not retract servo between probes
+            ProbeAction act;
-                if (code_seen('E') || code_seen('e') )
+            if (enhanced_g29) {
-                   {
+              if (yProbe == front_probe_bed_position && xCount == 0)
-                   if ((yProbe==FRONT_PROBE_BED_POSITION) && (xCount==0))
+                act = ProbeEngage;
-                       {
+              else if (yProbe == front_probe_bed_position + (yGridSpacing * (auto_bed_leveling_grid_points - 1)) && xCount == auto_bed_leveling_grid_points - 1)
-                        measured_z = probe_pt(xProbe, yProbe, z_before,1);
+                act = ProbeRetract;
-                       } else if ((yProbe==FRONT_PROBE_BED_POSITION + (yGridSpacing * (AUTO_BED_LEVELING_GRID_POINTS-1))) && (xCount == AUTO_BED_LEVELING_GRID_POINTS-1))
+              else
-                         {
+                act = ProbeStay;
-                         measured_z = probe_pt(xProbe, yProbe, z_before,3);
-                         } else {
-                           measured_z = probe_pt(xProbe, yProbe, z_before,2);
-                         }
-                    } else {
-                    measured_z = probe_pt(xProbe, yProbe, z_before);
             }
+            else
+              act = ProbeEngageRetract;
+
+            measured_z = probe_pt(xProbe, yProbe, z_before, act);
+
+            mean += measured_z;
 
             eqnBVector[probePointCounter] = measured_z;
+            eqnAMatrix[probePointCounter + 0 * abl2] = xProbe;
+            eqnAMatrix[probePointCounter + 1 * abl2] = yProbe;
+            eqnAMatrix[probePointCounter + 2 * abl2] = 1;
 
-                eqnAMatrix[probePointCounter + 0*auto_bed_leveling_grid_points*auto_bed_leveling_grid_points] = xProbe;
-                eqnAMatrix[probePointCounter + 1*auto_bed_leveling_grid_points*auto_bed_leveling_grid_points] = yProbe;
-                eqnAMatrix[probePointCounter + 2*auto_bed_leveling_grid_points*auto_bed_leveling_grid_points] = 1;
             probePointCounter++;
             xProbe += xInc;
-              }
+
-            }
+          } //xProbe
+
+        } //yProbe
+
         clean_up_after_endstop_move();
 
         // solve lsq problem
-            double *plane_equation_coefficients = qr_solve(auto_bed_leveling_grid_points*auto_bed_leveling_grid_points, 3, eqnAMatrix, eqnBVector);
+        double *plane_equation_coefficients = qr_solve(abl2, 3, eqnAMatrix, eqnBVector);
 
+        mean /= abl2;
+
+        if (verbose_level) {
           SERIAL_PROTOCOLPGM("Eqn coefficients: a: ");
           SERIAL_PROTOCOL(plane_equation_coefficients[0]);
           SERIAL_PROTOCOLPGM(" b: ");
           SERIAL_PROTOCOL(plane_equation_coefficients[1]);
           SERIAL_PROTOCOLPGM(" d: ");
           SERIAL_PROTOCOLLN(plane_equation_coefficients[2]);
+          if (verbose_level > 2) {
+            SERIAL_PROTOCOLPGM("Mean of sampled points: ");
+            SERIAL_PROTOCOL_F(mean, 6);
+            SERIAL_PROTOCOLPGM(" \n");
+          }
+        }
+
+        if (topo_flag) {
+
+          int xx, yy;
+
+          SERIAL_PROTOCOLPGM(" \nBed Height Topography: \n");
+          #if TOPO_ORIGIN == ORIGIN_FRONT_LEFT
+            for (yy = auto_bed_leveling_grid_points - 1; yy >= 0; yy--)
+          #else
+            for (yy = 0; yy < auto_bed_leveling_grid_points; yy++)
+          #endif
+            {
+              #if TOPO_ORIGIN == ORIGIN_BACK_RIGHT
+                for (xx = auto_bed_leveling_grid_points - 1; xx >= 0; xx--)
+              #else
+                for (xx = 0; xx < auto_bed_leveling_grid_points; xx++)
+              #endif
+                {
+                  int ind =
+                    #if TOPO_ORIGIN == ORIGIN_BACK_RIGHT || TOPO_ORIGIN == ORIGIN_FRONT_LEFT
+                      yy * auto_bed_leveling_grid_points + xx
+                    #elif TOPO_ORIGIN == ORIGIN_BACK_LEFT
+                      xx * auto_bed_leveling_grid_points + yy
+                    #elif TOPO_ORIGIN == ORIGIN_FRONT_RIGHT
+                      abl2 - xx * auto_bed_leveling_grid_points - yy - 1
+                    #endif
+                  ;
+                  float diff = eqnBVector[ind] - mean;
+                  if (diff >= 0.0)
+                    SERIAL_PROTOCOLPGM(" +");   // Watch column alignment in Pronterface
+                  else
+                    SERIAL_PROTOCOLPGM(" -");
+                  SERIAL_PROTOCOL_F(diff, 5);
+                } // xx
+                SERIAL_PROTOCOLPGM("\n");
+            } // yy
+            SERIAL_PROTOCOLPGM("\n");
+
+        } //topo_flag
 
 
         set_bed_level_equation_lsq(plane_equation_coefficients);
-
         free(plane_equation_coefficients);
 
-#else // AUTO_BED_LEVELING_GRID not defined
+      #else // !AUTO_BED_LEVELING_GRID
 
         // Probe at 3 arbitrary points
-            // Enhanced G29
-            
         float z_at_pt_1, z_at_pt_2, z_at_pt_3;
 
-            if (code_seen('E') || code_seen('e')) {
+        if (enhanced_g29) {
-              // probe 1               
+          // Basic Enhanced G29
-              z_at_pt_1 = probe_pt(ABL_PROBE_PT_1_X, ABL_PROBE_PT_1_Y, Z_RAISE_BEFORE_PROBING,1);
+          z_at_pt_1 = probe_pt(ABL_PROBE_PT_1_X, ABL_PROBE_PT_1_Y, Z_RAISE_BEFORE_PROBING, ProbeEngage);
-              // probe 2
+          z_at_pt_2 = probe_pt(ABL_PROBE_PT_2_X, ABL_PROBE_PT_2_Y, current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS, ProbeStay);
-              z_at_pt_2 = probe_pt(ABL_PROBE_PT_2_X, ABL_PROBE_PT_2_Y, current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS,2);
+          z_at_pt_3 = probe_pt(ABL_PROBE_PT_3_X, ABL_PROBE_PT_3_Y, current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS, ProbeRetract);
-              // probe 3
-              z_at_pt_3 = probe_pt(ABL_PROBE_PT_3_X, ABL_PROBE_PT_3_Y, current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS,3); 
         }
         else {
-              // probe 1
           z_at_pt_1 = probe_pt(ABL_PROBE_PT_1_X, ABL_PROBE_PT_1_Y, Z_RAISE_BEFORE_PROBING);
-              // probe 2
           z_at_pt_2 = probe_pt(ABL_PROBE_PT_2_X, ABL_PROBE_PT_2_Y, current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS);
-              // probe 3
           z_at_pt_3 = probe_pt(ABL_PROBE_PT_3_X, ABL_PROBE_PT_3_Y, current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS);
         }
         clean_up_after_endstop_move();
         set_bed_level_equation_3pts(z_at_pt_1, z_at_pt_2, z_at_pt_3);
 
+      #endif // !AUTO_BED_LEVELING_GRID
 
-#endif // AUTO_BED_LEVELING_GRID
       st_synchronize();
 
+      if (verbose_level > 0)
+        plan_bed_level_matrix.debug(" \n\nBed Level Correction Matrix:");
+
       // The following code correct the Z height difference from z-probe position and hotend tip position.
       // The Z height on homing is measured by Z-Probe, but the probe is quite far from the hotend.
       // When the bed is uneven, this height must be corrected.
-            real_z = float(st_get_position(Z_AXIS))/axis_steps_per_unit[Z_AXIS];  //get the real Z (since the auto bed leveling is already correcting the plane)
+      real_z = float(st_get_position(Z_AXIS)) / axis_steps_per_unit[Z_AXIS];  //get the real Z (since the auto bed leveling is already correcting the plane)
       x_tmp = current_position[X_AXIS] + X_PROBE_OFFSET_FROM_EXTRUDER;
       y_tmp = current_position[Y_AXIS] + Y_PROBE_OFFSET_FROM_EXTRUDER;
       z_tmp = current_position[Z_AXIS];
@@ -1901,11 +1999,13 @@ void process_commands()
       apply_rotation_xyz(plan_bed_level_matrix, x_tmp, y_tmp, z_tmp);         //Apply the correction sending the probe offset
       current_position[Z_AXIS] = z_tmp - real_z + current_position[Z_AXIS];   //The difference is added to current position and sent to planner.
       plan_set_position(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS]);
-#ifdef Z_PROBE_SLED
+
-            dock_sled(true, -SLED_DOCKING_OFFSET); // correct for over travel.
+      #ifdef Z_PROBE_SLED
-#endif // Z_PROBE_SLED
+        dock_sled(true, -SLED_DOCKING_OFFSET); // dock the probe, correcting for over-travel
+      #endif
     }
     break;
+
 #ifndef Z_PROBE_SLED
     case 30: // G30 Single Z Probe
         {