Added grbl planner Matlab simulator for test reference. Updated line number compile-time option.

- Added a grbl planner simulation tool that was written in Matlab and
Python. It was used to visualize the inner workings of the planner as a
program is streamed to it. The simulation assumes that the planner
buffer is empty, then filled, and kept filled. This is mainly for users
to see how the planner works.

- Updated some of the compile-time ifdefs when enabling line numbers.
The leaving the un-used line numbers in the function calls eats a
non-neglible amount of flash memory. So the new if-defs remove them.

config.h

@@ -86,12 +86,12 @@
 
 // Allows GRBL to tranck and report gcode line numbers.  Enabling this means that the planning buffer
 // goes from 18 or 16 to make room for the additional line number data in the plan_block_t struct
-// #define USE_LINE_NUMBERS
+// #define USE_LINE_NUMBERS // Disabled by default. Uncomment to enable.
 
 // Enables a second coolant control pin via the mist coolant g-code command M7 on the Arduino Uno
 // analog pin 5. Only use this option if you require a second coolant control pin.
 // NOTE: The M8 flood coolant control pin on analog pin 4 will still be functional regardless.
-// #define ENABLE_M7 // Mist coolant disabled by default. See config.h to enable/disable.
+// #define ENABLE_M7 // Disabled by default. Uncomment to enable.
 
 // ---------------------------------------------------------------------------------------
 // ADVANCED CONFIGURATION OPTIONS:

doc/test/grbl_sim.m

@@ -0,0 +1,437 @@
+% ----------------------------------------------------------------------------------------
+% The MIT License (MIT)
+% 
+% Copyright (c) 2014 Sungeun K. Jeon
+% 
+% Permission is hereby granted, free of charge, to any person obtaining a copy
+% of this software and associated documentation files (the "Software"), to deal
+% in the Software without restriction, including without limitation the rights
+% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+% copies of the Software, and to permit persons to whom the Software is
+% furnished to do so, subject to the following conditions:
+% 
+% The above copyright notice and this permission notice shall be included in
+% all copies or substantial portions of the Software.
+% 
+% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+% THE SOFTWARE.
+% ----------------------------------------------------------------------------------------
+
+% This MATLAB script was written for the purpose of being a GRBL planner simulator. This
+% simulator is a rough representation of the actual workings of Grbl on the Arduino, but
+% was used to hone and proof the actual planner by providing quick visual feedback on its 
+% functionality when experimented on. This script should be considered for educational 
+% purposes only. This script requires and executes a pre-parsed g-code file from the 
+% matlab_convert.py script that is in a specific non-g-code format. 
+
+% There will be two figures plotted. The first is the line motion paths of the complete
+% g-code program. The second is a representation of Grbl's planner buffer as new line
+% motions are fed to it, plotting the velocity profiles the stepper motors will execute.
+% Every time the user inputs an <Enter>, this feeds the simulator planner one line motion
+% block. The left side is the first block in the buffer and the one that will be executed
+% by the stepper module first. The right side is the end of the planner buffer, where the
+% most recent streamed block is appended onto the planner buffer. Grbl's planner 
+% optimizes the velocity profiles between the beginning and end of the buffer based on 
+% the acceleration limits, intended velocity/feedrate, and line motion junction angles
+% with their corresponding velocity limits (i.e. junctions with acute angles needs to come
+% to a complete stop vs straight junctions can continue through at full speed.)
+
+% ----------------------------------------------------------------------------------------
+
+
+% Main function 
+% NOTE: This is just a way to keep all functions in one place, but all non-global variables 
+%   are cleared as soon as this script completes.
+function main()
+
+% Load pre-parsed gcode moves.
+close all;
+warning off;
+clearvars -global
+fid = fopen('matlab.gcode','r');
+gcode = textscan(fid,'%d8%f32%f32%f32%f32');
+nblock = length(gcode{1});
+
+% Plot all g-code moves.
+figure
+line(gcode{3},gcode{4},gcode{5});
+axis equal;
+% axis([min(gcode{3}) max(gcode{3}) min(gcode{4}) max(gcode{4}) min(gcode{5}) max(gcode{5})]);
+title('G-code programming line motions');
+view(3);
+
+% Set up figure for planner queue
+figure
+
+% Print help.
+disp('<NOTE: Press Enter to Advance One G-Code Line Motion>');
+disp('   BLUE line indicates completed planner blocks that require no recalculation.');
+disp('   RED line indicates planner blocks that have been recalculated.');
+disp('   GREEN line indicates the location of the BPLANNED pointer. Always a recalculated block.');
+disp('   BLACK dotted-line and ''x'' indicates block nominal speed and max junction velocity, respectively.');
+disp('   CYAN ''.'' indicates block initial entry speed.');
+
+% Define Grbl settings.
+BUFFER_SIZE = 18; % Number of planner blocks in its ring buffer.
+steps_per_mm = 200;
+seekrate = 2500; % mm/min
+acceleration = [100 100 100]; % mm/sec^2 [ X Y Z ] axes
+junction_deviation = 0.1; % mm. See Grbl documentation on this parameter.
+inch_2_mm = 25.4;
+ACCELERATION_TICKS_PER_SECOND = 100;
+
+gcode{2} = gcode{2};
+gcode{2} = inch_2_mm*gcode{2};
+gcode{3} = inch_2_mm*gcode{3};
+gcode{4} = inch_2_mm*gcode{4};
+gcode{5} = inch_2_mm*gcode{5};
+
+% Initialize blocks
+block.steps = [];
+block.step_event_count = [];
+block.delta_mm = [];
+block.millimeters = [];
+block.acceleration = [];
+block.speed = [];
+block.nominal_speed = [];
+block.max_entry_speed = [];
+block.entry_speed = [];
+block.recalculate_flag = false;
+for i = 2:BUFFER_SIZE
+  block(i) = block(1);
+end
+
+% Initialize planner
+position = [0 0 0];
+prev_unit_vec = [0 0 0];
+previous_nominal_speed = 0;
+pos = 0;
+
+% BHEAD and BTAIL act as pointers to the block head and tail. 
+% BPLANNED acts as a pointer of the location of the end of a completed/optimized plan.
+bhead = 1;
+btail = 1;
+bplanned = 1;
+
+global block bhead btail bplanned nind acceleration BUFFER_SIZE pos ACCELERATION_TICKS_PER_SECOND
+
+% Main loop. Simulates plan_buffer_line(). All of the precalculations for the newest incoming
+% block occurs here. Anything independent of the planner changes.
+for i = 1:nblock
+    
+  target = round([gcode{3}(i) gcode{4}(i) gcode{5}(i)].*steps_per_mm);
+  if gcode{1}(i) == 1
+    feedrate = gcode{2}(i);
+  else
+    feedrate = seekrate;
+  end
+  
+  nind = next_block_index(bhead);
+  if nind == btail
+    % Simulate a constantly full buffer. Move buffer tail. 
+    bind = next_block_index(btail);
+    % Push planned pointer if encountered. Prevents it from looping back around the ring buffer.    
+    if btail == bplanned; bplanned = bind; end
+    btail = bind;
+  end
+
+  block(bhead).steps = abs(target-position);
+  block(bhead).step_event_count = max(block(bhead).steps);
+
+  % Bail if this is a zero-length block
+  if block(bhead).step_event_count == 0
+    disp(['Zero-length block in line ',int2str(i)]);
+  else
+
+    % Compute path vector in terms of absolute step target and current positions  
+    delta_mm = single((target-position)./steps_per_mm);
+    block(bhead).millimeters = single(norm(delta_mm));
+    inverse_millimeters = single(1/block(bhead).millimeters);
+ 
+    % Compute path unit vector                            
+    unit_vec = delta_mm/block(bhead).millimeters;
+ 
+    % Calculate speed in mm/minute for each axis
+    inverse_minute = single(feedrate * inverse_millimeters);
+    block(bhead).speed = delta_mm*inverse_minute;
+    block(bhead).nominal_speed = block(bhead).millimeters*inverse_minute;
+    
+    % Calculate block acceleration. Operates on absolute value of unit vector.
+    [max_acc,ind] = max(abs(unit_vec)./acceleration); % Determine limiting acceleration
+    block(bhead).acceleration = acceleration(ind)/abs(unit_vec(ind));   
+    
+    % Compute maximum junction speed
+    block(bhead).max_entry_speed = 0.0;
+    if previous_nominal_speed > 0.0 
+      cos_theta = dot(-previous_unit_vec,unit_vec);                           
+      if (cos_theta < 0.95) 
+          block(bhead).max_entry_speed = min([block(bhead).nominal_speed,previous_nominal_speed]);
+        if (cos_theta > -0.95) 
+          sin_theta_d2 = sqrt(0.5*(1.0-cos_theta));
+          block(bhead).max_entry_speed = min([block(bhead).max_entry_speed,sqrt(block(bhead).acceleration*3600*junction_deviation*sin_theta_d2/(1.0-sin_theta_d2))]);
+        end
+      end
+    end
+    
+    block(bhead).entry_speed = 0; % Just initialize. Set accurately in the replanning function.  
+    block(bhead).recalculate_flag = true; % Plotting flag to indicate this block has been updated.
+    
+    previous_unit_vec = unit_vec;
+    previous_nominal_speed = block(bhead).nominal_speed;
+    position = target;
+    
+    bhead = nind; % Block complete. Push buffer pointer.
+    planner_recalculate();   
+     
+    plot_buffer_velocities();
+  end
+end
+return
+
+% Computes the next block index in the planner ring buffer
+function block_index = next_block_index(block_index) 
+global BUFFER_SIZE
+  block_index = block_index + 1;
+  if block_index > BUFFER_SIZE
+    block_index = 1;
+  end
+return
+
+% Computes the previous block index in the planner ring buffer
+function block_index = prev_block_index(block_index) 
+global BUFFER_SIZE
+  block_index = block_index-1;
+  if block_index < 1
+    block_index = BUFFER_SIZE;
+  end
+return
+
+
+% Planner recalculate function. The magic happens here.
+function planner_recalculate(block) 
+
+  global block bhead btail bplanned acceleration
+
+  bind = prev_block_index(bhead);
+  if bind == bplanned; return; end  % Bail, if only one block in buffer. Can't be operated on.
+  
+  % Reverse Pass: Coarsely maximize all possible deceleration curves back-planning from the last
+  % block in buffer. Cease planning when the last optimal planned or tail pointer is reached.
+  % NOTE: Forward pass will later refine and correct the reverse pass to create an optimal plan.
+  next = [];
+  curr = bind;  % Last block in buffer.
+
+  % Calculate maximum entry speed for last block in buffer, where the exit speed is always zero.
+  block(curr).entry_speed = min([block(curr).max_entry_speed,sqrt(2*block(curr).acceleration*60*60*block(curr).millimeters)]);
+
+  bind = prev_block_index(bind); % Btail or second to last block
+  if (bind == bplanned)
+     % Only two plannable blocks in buffer. Reverse pass complete.
+     % Check if the first block is the tail. If so, notify stepper module to update its current parameters.
+     % if bind == btail; update_tail_block; end
+  else    
+    % Three or more plannable blocks in buffer. Loop it.
+    while bind ~= bplanned % Loop until bplanned point hits. Replans to last plan point.
+      next = curr; 
+      curr = bind;
+      bind = prev_block_index( bind ); % Previous block pointer.  
+            
+      % Check if the first block is the tail. If so, notify stepper module to update its current parameters.
+      % if bind == btail; update_tail_block; end
+                   
+      % Compute maximum entry speed decelerating over the current block from its exit speed.
+      if block(curr).entry_speed ~= block(curr).max_entry_speed  
+        block(curr).recalculate_flag = true; % Plotting flag to indicate this block has been updated.
+        block(curr).entry_speed = min([ block(curr).max_entry_speed,...
+                                        sqrt(block(next).entry_speed^2 + 2*block(curr).acceleration*60*60*block(curr).millimeters)]);                                        
+      end    
+
+    end
+  end
+
+  % For two blocks, reverse pass is skipped, but forward pass plans second block entry speed
+  % onward. This prevents the first, or the potentially executing block, from being over-written.
+  % NOTE: Can never be bhead, since bsafe is always in active buffer.
+  next = bplanned;  
+  bind = next_block_index(bplanned); % Start at bplanned
+  while bind ~= bhead
+    curr = next;
+    next = bind;
+    
+    % An acceleration block is always an optimally planned block since it starts from the first 
+    % block's current speed or a maximum junction speed. Compute accelerations from this block 
+    % and update the next block's entry speed.
+    if (block(curr).entry_speed < block(next).entry_speed)
+      % Once speed is set by forward planner, the plan for this block is finished and optimal.
+      % Increment the planner pointer forward one block.      
+        
+      entry_speed = sqrt(block(curr).entry_speed^2 + 2*block(curr).acceleration*60*60*block(curr).millimeters);
+      if (block(next).entry_speed > entry_speed)
+        block(next).entry_speed = entry_speed;
+        bplanned = bind;
+      end
+
+    end
+    
+    % Check if the next block entry speed is at max_entry_speed. If so, move the planned pointer, since
+    % this entry speed cannot be improved anymore and all prior blocks have been completed and optimally planned.
+    if block(next).entry_speed == block(next).max_entry_speed
+      bplanned = bind;
+    end
+    
+    % Recalculate trapezoid can be installed here, since it scans through all of the plannable blocks.
+    % NOTE: Eventually this will only be computed when being executed.
+    
+    bind = next_block_index( bind );
+
+  end
+  
+return
+
+% ----------------------------------------------------------------------------------------
+% PLOTTING FUNCTIONS
+
+% Plots the entire buffer plan into a MATLAB figure to visual the plan.
+%   BLUE line indicates completed planner blocks that require no recalculation.
+%   RED line indicates planner blocks that have been recalculated.
+%   GREEN line indicates the location of the BPLANNED pointer. Always a recalculated block.
+%   BLACK dotted-line and 'x' indicates block nominal speed and max junction velocity, respectively.
+%   CYAN '.' indicates block initial entry speed.
+function plot_buffer_velocities() 
+  global block bhead btail bplanned acceleration pos ACCELERATION_TICKS_PER_SECOND
+  bind = btail;
+  curr = [];
+  next = [];
+  
+  pos_initial = 0;
+  pos = 0;
+  while bind ~= bhead
+    curr = next;
+    next = bind;
+    hold on;
+    if ~isempty(curr) 
+      accel_d = estimate_acceleration_distance(block(curr).entry_speed, block(curr).nominal_speed, block(curr).acceleration*60*60);
+      decel_d = estimate_acceleration_distance(block(curr).nominal_speed, block(next).entry_speed,-block(curr).acceleration*60*60);
+      plateau_d = block(curr).millimeters-accel_d-decel_d;
+      if plateau_d < 0
+        accel_d = intersection_distance(block(curr).entry_speed, block(next).entry_speed, block(curr).acceleration*60*60, block(curr).millimeters);
+        if accel_d < 0
+          accel_d = 0;
+        elseif accel_d > block(curr).millimeters
+          accel_d = block(curr).millimeters;
+        end
+        plateau_d = 0;
+      end 
+      color = 'b'; 
+      if (block(curr).recalculate_flag || block(next).recalculate_flag) 
+        block(curr).recalculate_flag = false;
+        color = 'r'; 
+      end
+      if bplanned == curr
+        color = 'g'; 
+      end
+      
+      plot_trap(pos,block(curr).entry_speed,block(next).entry_speed,block(curr).nominal_speed,block(curr).acceleration,accel_d,plateau_d,block(curr).millimeters,color)
+      plot([pos pos+block(curr).millimeters],block(curr).nominal_speed*[1 1],'k:') % BLACK dotted indicates
+      plot(pos,block(curr).max_entry_speed,'kx')
+
+      pos = pos + block(curr).millimeters;
+      plot(pos,block(next).entry_speed,'c.');
+    end
+    bind = next_block_index( bind );
+  end
+
+  accel_d = estimate_acceleration_distance(block(next).entry_speed, block(next).nominal_speed, block(next).acceleration*60*60);
+  decel_d = estimate_acceleration_distance(block(next).nominal_speed, 0, -block(next).acceleration*60*60);
+  plateau_d = block(next).millimeters-accel_d-decel_d;
+  if plateau_d < 0
+     accel_d = intersection_distance(block(next).entry_speed, 0, block(next).acceleration*60*60, block(next).millimeters);
+     if accel_d < 0
+       accel_d = 0;
+     elseif accel_d > block(next).millimeters
+       accel_d = block(next).millimeters;
+     end
+     plateau_d = 0;
+   end 
+   block(next).recalculate_flag = false;
+   color = 'r';
+   if bplanned == next
+     color= 'g';
+   end
+   
+  plot_trap(pos,block(next).entry_speed,0,block(next).nominal_speed,block(next).acceleration,accel_d,plateau_d,block(next).millimeters,color)
+  plot([pos pos+block(next).millimeters],block(next).nominal_speed*[1 1],'k:')
+  plot(pos,block(next).max_entry_speed,'kx')
+
+  plot(pos,block(next).entry_speed,'.');
+  pos = pos + block(next).millimeters;
+  plot(pos,0,'rx');
+  xlabel('mm');
+  ylabel('mm/sec');
+  xlim([pos_initial pos])
+  title('Planner buffer optimized velocity profile');
+  pause();
+  hold off;
+  
+  plot(pos,0)
+return
+
+
+function d_a = estimate_acceleration_distance(initial_rate, target_rate, acceleration,rate_delta)
+  d_a = (target_rate*target_rate-initial_rate*initial_rate)/(2*acceleration);
+return
+
+function d_i = intersection_distance(initial_rate, final_rate, acceleration, distance, rate_delta)
+  d_i = (2*acceleration*distance-initial_rate*initial_rate+final_rate*final_rate)/(4*acceleration);
+return
+
+
+% Simply plots the ac/de-celeration curves and plateaus of a trapezoid.
+function plot_trap(pos,initial_rate,final_rate,rate,accel,accel_d,plateau_d,millimeters,color)
+
+  dx = 1.0; % Line segment length
+  linex = [pos]; liney = [initial_rate];
+
+  % Acceleration
+  np = floor(accel_d/dx);
+  if np
+    v = initial_rate;
+    for i = 1:np
+      v = sqrt(v^2+2*accel*60*60*dx);
+      linex = [linex pos+i*dx];
+      liney = [liney v];
+    end
+  end
+  
+  % Plateau
+  v = sqrt(initial_rate^2 + 2*accel*60*60*accel_d);
+  if v < rate
+    rate = v;
+  end
+  linex = [linex pos+[accel_d accel_d+plateau_d]];
+  liney = [liney [rate rate]];
+  
+  % Deceleration
+  np = floor((millimeters-accel_d-plateau_d)/dx);
+  if np
+    v = rate;
+    for i = 1:np
+      v = sqrt(v^2-2*accel*60*60*dx);
+      linex = [linex pos+i*dx+accel_d+plateau_d];
+      liney = [liney v];
+    end
+  end        
+        
+  linex = [linex pos+millimeters];
+  liney = [ liney final_rate];
+  plot(linex,liney,color);
+
+return
+
+
+

doc/test/matlab_convert.py

@@ -0,0 +1,270 @@
+#!/usr/bin/env python
+"""\
+The MIT License (MIT)
+
+Copyright (c) 2014 Sungeun K. Jeon
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+----------------------------------------------------------------------------------------
+"""
+"""\
+G-code preprocessor for the grbl_sim.m MATLAB script. Parses the g-code program to a
+specific file format for the MATLAB script to use. Based on PreGrbl by @chamnit.
+
+How to use: When running this python script, it will process the g-code program under
+the filename "test.gcode" (may be changed below) and produces a file called "matlab.gcode"
+that the grbl_sim.m MATLAB script will search for and execute.
+"""
+
+import re
+from math import *
+from copy import *
+
+# -= SETTINGS =-
+filein = 'test.gcode'   # Input file name
+fileout = 'matlab.gcode'  # Output file name
+ndigits_in = 4 # inch significant digits after '.'
+ndigits_mm = 2 # mm significant digits after '.'
+# mm_per_arc_segment = 0.38 # mm per arc segment      
+arc_tolerance = 0.00005*25.4
+n_arc_correction = 20
+inch2mm = 25.4 # inch to mm conversion scalar
+verbose = False  # Verbose flag to show all progress
+remove_unsupported = True   # Removal flag for all unsupported statements
+
+# Initialize parser state
+gc = { 'current_xyz' : [0,0,0], 
+       'feed_rate' : 0,         # F0
+       'motion_mode' : 'SEEK',  # G00
+       'plane_axis' : [0,1,2],  # G17
+       'inches_mode' : False,   # G21
+       'inverse_feedrate_mode' : False, # G94
+       'absolute_mode' : True}  # G90
+
+def unit_conv(val) : # Converts value to mm
+    if gc['inches_mode'] : val *= inch2mm
+    return(val)
+
+def fout_conv(val) : # Returns converted value as rounded string for output file.
+    if gc['inches_mode'] : return( str(round(val/inch2mm,ndigits_in)) )
+    else : return( str(round(val,ndigits_mm)) )
+
+# Open g-code file
+fin = open(filein,'r');
+fout = open(fileout,'w');
+
+# Iterate through g-code file
+l_count = 0
+for line in fin:
+    l_count += 1 # Iterate line counter
+    
+    # Strip comments/spaces/tabs/new line and capitalize. Comment MSG not supported.
+    block = re.sub('\s|\(.*?\)','',line).upper() 
+    block = re.sub('\\\\','',block) # Strip \ block delete character
+    block = re.sub('%','',block) # Strip % program start/stop character
+    
+    if len(block) == 0 :  # Ignore empty blocks
+        
+        print "Skipping: " + line.strip()
+        
+    else :  # Process valid g-code clean block. Assumes no block delete characters or comments
+        
+        g_cmd = re.findall(r'[^0-9\.\-]+',block) # Extract block command characters
+        g_num = re.findall(r'[0-9\.\-]+',block) # Extract block numbers
+        
+        # G-code block error checks
+        # if len(g_cmd) != len(g_num) : print block; raise Exception('Invalid block. Unbalanced word and values.')
+        if 'N' in g_cmd :
+            if g_cmd[0]!='N': raise Exception('Line number must be first command in line.')
+            if g_cmd.count('N') > 1: raise Exception('More than one line number in block.')
+            g_cmd = g_cmd[1:]  # Remove line number word
+            g_num = g_num[1:]
+        # Block item repeat checks? (0<=n'M'<5, G/M modal groups)
+        
+        # Initialize block state
+        blk = { 'next_action' : 'DEFAULT',
+                'absolute_override' : False,
+                'target_xyz' : deepcopy(gc['current_xyz']),
+                'offset_ijk' : [0,0,0],
+                'radius_mode' : False, 
+                'unsupported': [] }
+
+        # Pass 1
+        for cmd,num in zip(g_cmd,g_num) :
+            fnum = float(num)
+            inum = int(fnum)
+            if cmd is 'G' :
+                if   inum is 0 : gc['motion_mode'] = 'SEEK'
+                elif inum is 1 : gc['motion_mode'] = 'LINEAR'
+                elif inum is 2 : gc['motion_mode'] = 'CW_ARC'
+                elif inum is 3 : gc['motion_mode'] = 'CCW_ARC'
+                elif inum is 4 : blk['next_action'] = 'DWELL'
+                elif inum is 17 : gc['plane_axis'] = [0,1,2]    # Select XY Plane
+                elif inum is 18 : gc['plane_axis'] = [0,2,1]    # Select XZ Plane
+                elif inum is 19 : gc['plane_axis'] = [1,2,0]    # Select YZ Plane
+                elif inum is 20 : gc['inches_mode'] = True      
+                elif inum is 21 : gc['inches_mode'] = False
+                elif inum in [28,30] : blk['next_action'] = 'GO_HOME'
+                elif inum is 53 : blk['absolute_override'] = True
+                elif inum is 54 : pass
+                elif inum is 80 : gc['motion_mode'] = 'MOTION_CANCEL'
+                elif inum is 90 : gc['absolute_mode'] = True
+                elif inum is 91 : gc['absolute_mode'] = False
+                elif inum is 92 : blk['next_action'] = 'SET_OFFSET'
+                elif inum is 93 : gc['inverse_feedrate_mode'] = True
+                elif inum is 94 : gc['inverse_feedrate_mode'] = False
+                else : 
+                    print 'Unsupported command ' + cmd + num + ' on line ' + str(l_count) 
+                    if remove_unsupported : blk['unsupported'].append(zip(g_cmd,g_num).index((cmd,num)))
+            elif cmd is 'M' :
+                if   inum in [0,1] : pass   # Program Pause
+                elif inum in [2,30,60] : pass   # Program Completed
+                elif inum is 3 : pass   # Spindle Direction 1
+                elif inum is 4 : pass   # Spindle Direction -1
+                elif inum is 5 : pass   # Spindle Direction 0
+                else : 
+                    print 'Unsupported command ' + cmd + num + ' on line ' + str(l_count) 
+                    if remove_unsupported : blk['unsupported'].append(zip(g_cmd,g_num).index((cmd,num)))
+            elif cmd is 'T' : pass      # Tool Number
+            
+        # Pass 2
+        for cmd,num in zip(g_cmd,g_num) :
+            fnum = float(num)         
+            if   cmd is 'F' : gc['feed_rate'] = unit_conv(fnum)   # Feed Rate
+            elif cmd in ['I','J','K'] : blk['offset_ijk'][ord(cmd)-ord('I')] = unit_conv(fnum) # Arc Center Offset
+            elif cmd is 'N' : pass
+            elif cmd is 'P' : p = fnum  # Misc value parameter
+            elif cmd is 'R' : r = unit_conv(fnum); blk['radius_mode'] = True    # Arc Radius Mode
+            elif cmd is 'S' : pass      # Spindle Speed
+            elif cmd in ['X','Y','Z'] : # Target Coordinates
+                if (gc['absolute_mode'] | blk['absolute_override']) :
+                    blk['target_xyz'][ord(cmd)-ord('X')] = unit_conv(fnum)
+                else :
+                    blk['target_xyz'][ord(cmd)-ord('X')] += unit_conv(fnum)
+
+        # Execute actions
+        if   blk['next_action'] is 'GO_HOME' : 
+            gc['current_xyz'] = deepcopy(blk['target_xyz']) # Update position      
+        elif blk['next_action'] is 'SET_OFFSET' : 
+            pass 
+        elif blk['next_action'] is 'DWELL' :
+            if p < 0 : raise Exception('Dwell time negative.')
+        else : # 'DEFAULT'
+            if gc['motion_mode'] is 'SEEK' : 
+                fout.write('0 '+fout_conv(gc['feed_rate']))
+                fout.write(' '+fout_conv(blk['target_xyz'][0]))
+                fout.write(' '+fout_conv(blk['target_xyz'][1]))
+                fout.write(' '+fout_conv(blk['target_xyz'][2]))
+                fout.write('\n')  
+                gc['current_xyz'] = deepcopy(blk['target_xyz']) # Update position
+            elif gc['motion_mode'] is 'LINEAR' :
+                fout.write('1 '+fout_conv(gc['feed_rate']))
+                fout.write(' '+fout_conv(blk['target_xyz'][0]))
+                fout.write(' '+fout_conv(blk['target_xyz'][1]))
+                fout.write(' '+fout_conv(blk['target_xyz'][2]))
+                fout.write('\n')  
+                gc['current_xyz'] = deepcopy(blk['target_xyz']) # Update position
+            elif gc['motion_mode'] in ['CW_ARC','CCW_ARC'] :
+                axis = gc['plane_axis']
+                
+                # Convert radius mode to ijk mode
+                if blk['radius_mode'] :
+                    x = blk['target_xyz'][axis[0]]-gc['current_xyz'][axis[0]]
+                    y = blk['target_xyz'][axis[1]]-gc['current_xyz'][axis[1]]
+                    if not (x==0 and y==0) : raise Exception('Same target and current XYZ not allowed in arc radius mode.') 
+                    h_x2_div_d = -sqrt(4 * r*r - x*x - y*y)/hypot(x,y)
+                    if isnan(h_x2_div_d) : raise Exception('Floating point error in arc conversion')
+                    if gc['motion_mode'] is 'CCW_ARC' : h_x2_div_d = -h_x2_div_d
+                    if r < 0 : h_x2_div_d = -h_x2_div_d
+                    blk['offset_ijk'][axis[0]] = (x-(y*h_x2_div_d))/2;
+                    blk['offset_ijk'][axis[1]] = (y+(x*h_x2_div_d))/2;
+                else :
+                    radius = sqrt(blk['offset_ijk'][axis[0]]**2+blk['offset_ijk'][axis[1]]**2)
+
+                center_axis0 = gc['current_xyz'][axis[0]]+blk['offset_ijk'][axis[0]]
+                center_axis1 = gc['current_xyz'][axis[1]]+blk['offset_ijk'][axis[1]]
+                linear_travel = blk['target_xyz'][axis[2]]-gc['current_xyz'][axis[2]]
+                r_axis0 = -blk['offset_ijk'][axis[0]]
+                r_axis1 = -blk['offset_ijk'][axis[1]]
+                rt_axis0 = blk['target_xyz'][axis[0]] - center_axis0;
+                rt_axis1 = blk['target_xyz'][axis[1]] - center_axis1;
+                clockwise_sign = 1
+                if gc['motion_mode'] is 'CW_ARC' : clockwise_sign = -1
+
+                angular_travel = atan2(r_axis0*rt_axis1-r_axis1*rt_axis0, r_axis0*rt_axis0+r_axis1*rt_axis1)
+                if gc['motion_mode'] is 'CW_ARC' :
+                    if angular_travel >= 0 :
+                        angular_travel -= 2*pi
+                else :
+                    if angular_travel <= 0 :
+                        angular_travel += 2*pi
+               
+                millimeters_of_travel = sqrt((angular_travel*radius)**2 + abs(linear_travel)**2)
+
+                mm_per_arc_segment = sqrt(4*(2*radius*arc_tolerance-arc_tolerance**2))
+                segments = int(millimeters_of_travel/mm_per_arc_segment)
+                print segments
+                print l_count
+                theta_per_segment = angular_travel/segments
+                linear_per_segment = linear_travel/segments
+                cos_T = 1-0.5*theta_per_segment*theta_per_segment
+                sin_T = theta_per_segment-theta_per_segment**3/6
+                print(fout_conv(mm_per_arc_segment))  
+                print theta_per_segment*180/pi
+                                
+                arc_target = [0,0,0]
+                arc_target[axis[2]] = gc['current_xyz'][axis[2]]
+
+                count = 0
+                for i in range(1,segments+1) :
+                    if i < segments :
+                        if count < n_arc_correction :
+                            r_axisi = r_axis0*sin_T + r_axis1*cos_T       
+                            r_axis0 = r_axis0*cos_T - r_axis1*sin_T
+                            r_axis1 = deepcopy(r_axisi)
+                            count += 1
+                        else :
+                            cos_Ti = cos((i-1)*theta_per_segment)
+                            sin_Ti = sin((i-1)*theta_per_segment)
+                            print n_arc_correction*(r_axis0 -( -blk['offset_ijk'][axis[0]]*cos_Ti + blk['offset_ijk'][axis[1]]*sin_Ti))
+                            print n_arc_correction*(r_axis1 -( -blk['offset_ijk'][axis[0]]*sin_Ti - blk['offset_ijk'][axis[1]]*cos_Ti))
+                            cos_Ti = cos(i*theta_per_segment)
+                            sin_Ti = sin(i*theta_per_segment)
+                            r_axis0 = -blk['offset_ijk'][axis[0]]*cos_Ti + blk['offset_ijk'][axis[1]]*sin_Ti
+                            r_axis1 = -blk['offset_ijk'][axis[0]]*sin_Ti - blk['offset_ijk'][axis[1]]*cos_Ti
+                            count = 0
+                        arc_target[axis[0]] = center_axis0 + r_axis0
+                        arc_target[axis[1]] = center_axis1 + r_axis1
+                        arc_target[axis[2]] += linear_per_segment
+                    else : 
+                        arc_target = deepcopy(blk['target_xyz']) # Last segment at target_xyz
+                    # Write only changed variables. 
+                    fout.write('1 '+fout_conv(gc['feed_rate']))
+                    fout.write(' '+fout_conv(arc_target[0]))
+                    fout.write(' '+fout_conv(arc_target[1]))
+                    fout.write(' '+fout_conv(arc_target[2]))
+                    fout.write('\n')            
+                    gc['current_xyz'] = deepcopy(arc_target) # Update position
+
+
+print 'Done!'
+
+# Close files
+fin.close()
+fout.close()

gcode.c

@@ -101,7 +101,9 @@ uint8_t gc_execute_line(char *line)
   float target[N_AXIS];
   clear_vector(target); // XYZ(ABC) axes parameters.
 
+  #ifdef USE_LINE_NUMBERS
   int32_t line_number = 0;
+  #endif
   gc.arc_radius = 0;
   clear_vector(gc.arc_offset); // IJK Arc offsets are incremental. Value of zero indicates no change.
 
@@ -227,7 +229,11 @@ uint8_t gc_execute_line(char *line)
         break;
       case 'I': case 'J': case 'K': gc.arc_offset[letter-'I'] = to_millimeters(value); break;
       case 'L': l = trunc(value); break;
-      case 'N': line_number = trunc(value); break;
+      case 'N': 
+        #ifdef USE_LINE_NUMBERS
+        line_number = trunc(value); 
+        #endif
+        break;
       case 'P': p = value; break;                    
       case 'R': gc.arc_radius = to_millimeters(value); break;
       case 'S': 
@@ -331,7 +337,11 @@ uint8_t gc_execute_line(char *line)
             target[idx] = gc.position[idx];
           }
         }
+        #ifdef USE_LINE_NUMBERS
         mc_line(target, -1.0, false, line_number);
+        #else
+        mc_line(target, -1.0, false);
+        #endif
       }
       // Retreive G28/30 go-home position data (in machine coordinates) from EEPROM
       float coord_data[N_AXIS];
@@ -340,7 +350,11 @@ uint8_t gc_execute_line(char *line)
       } else {
         if (!settings_read_coord_data(SETTING_INDEX_G30,coord_data)) { return(STATUS_SETTING_READ_FAIL); }
       }
+      #ifdef USE_LINE_NUMBERS
       mc_line(coord_data, -1.0, false, line_number); 
+      #else
+      mc_line(coord_data, -1.0, false); 
+      #endif
       memcpy(gc.position, coord_data, sizeof(coord_data)); // gc.position[] = coord_data[];
       axis_words = 0; // Axis words used. Lock out from motion modes by clearing flags.
       break;
@@ -411,7 +425,13 @@ uint8_t gc_execute_line(char *line)
         break;
       case MOTION_MODE_SEEK:
         if (!axis_words) { FAIL(STATUS_INVALID_STATEMENT);} 
-        else { mc_line(target, -1.0, false, line_number); }
+        else { 
+          #ifdef USE_LINE_NUMBERS
+          mc_line(target, -1.0, false, line_number);
+          #else
+          mc_line(target, -1.0, false);
+          #endif
+        }
         break;
       case MOTION_MODE_LINEAR:
         // TODO: Inverse time requires F-word with each statement. Need to do a check. Also need
@@ -419,7 +439,13 @@ uint8_t gc_execute_line(char *line)
         // and after an inverse time move and then check for non-zero feed rate each time. This
         // should be efficient and effective.
         if (!axis_words) { FAIL(STATUS_INVALID_STATEMENT);} 
-        else { mc_line(target, (gc.inverse_feed_rate_mode) ? inverse_feed_rate : gc.feed_rate, gc.inverse_feed_rate_mode, line_number); }
+        else { 
+          #ifdef USE_LINE_NUMBERS
+          mc_line(target, (gc.inverse_feed_rate_mode) ? inverse_feed_rate : gc.feed_rate, gc.inverse_feed_rate_mode, line_number);
+          #else
+          mc_line(target, (gc.inverse_feed_rate_mode) ? inverse_feed_rate : gc.feed_rate, gc.inverse_feed_rate_mode);
+          #endif
+        }
         break;
       case MOTION_MODE_CW_ARC: case MOTION_MODE_CCW_ARC:
         // Check if at least one of the axes of the selected plane has been specified. If in center 
@@ -441,9 +467,15 @@ uint8_t gc_execute_line(char *line)
           if (gc.motion_mode == MOTION_MODE_CW_ARC) { isclockwise = true; }
     
           // Trace the arc
+          #ifdef USE_LINE_NUMBERS
           mc_arc(gc.position, target, gc.arc_offset, gc.plane_axis_0, gc.plane_axis_1, gc.plane_axis_2,
             (gc.inverse_feed_rate_mode) ? inverse_feed_rate : gc.feed_rate, gc.inverse_feed_rate_mode,
             gc.arc_radius, isclockwise, line_number);
+          #else
+          mc_arc(gc.position, target, gc.arc_offset, gc.plane_axis_0, gc.plane_axis_1, gc.plane_axis_2,
+            (gc.inverse_feed_rate_mode) ? inverse_feed_rate : gc.feed_rate, gc.inverse_feed_rate_mode,
+            gc.arc_radius, isclockwise);
+          #endif
         }            
         break;
     }

limits.c

@@ -168,7 +168,11 @@ void limits_go_home(uint8_t cycle_mask)
   
     // Perform homing cycle. Planner buffer should be empty, as required to initiate the homing cycle.
     uint8_t limit_state;
+    #ifdef USE_LINE_NUMBERS
     plan_buffer_line(target, homing_rate, false, HOMING_CYCLE_LINE_NUMBER); // Bypass mc_line(). Directly plan homing motion.
+    #else
+    plan_buffer_line(target, homing_rate, false); // Bypass mc_line(). Directly plan homing motion.
+    #endif
     st_prep_buffer(); // Prep and fill segment buffer from newly planned block.
     st_wake_up(); // Initiate motion
     do {
@@ -225,7 +229,11 @@ void limits_go_home(uint8_t cycle_mask)
     }
   }
   plan_sync_position(); // Sync planner position to current machine position for pull-off move.
+  #ifdef USE_LINE_NUMBERS
   plan_buffer_line(target, settings.homing_seek_rate, false, HOMING_CYCLE_LINE_NUMBER); // Bypass mc_line(). Directly plan motion.
+  #else
+  plan_buffer_line(target, settings.homing_seek_rate, false); // Bypass mc_line(). Directly plan motion.
+  #endif
   
   // Initiate pull-off using main motion control routines. 
   // TODO : Clean up state routines so that this motion still shows homing state.

motion_control.c

@@ -39,7 +39,11 @@
 // segments, must pass through this routine before being passed to the planner. The seperation of
 // mc_line and plan_buffer_line is done primarily to place non-planner-type functions from being
 // in the planner and to let backlash compensation or canned cycle integration simple and direct.
+#ifdef USE_LINE_NUMBERS
 void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate, int32_t line_number)
+#else
+void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate)
+#endif
 {
   // If enabled, check for soft limit violations. Placed here all line motions are picked up
   // from everywhere in Grbl.
@@ -71,7 +75,11 @@ void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate, int32_t l
     else { break; }
   } while (1);
 
+  #ifdef USE_LINE_NUMBERS
   plan_buffer_line(target, feed_rate, invert_feed_rate, line_number);
+  #else
+  plan_buffer_line(target, feed_rate, invert_feed_rate);
+  #endif
   
   // If idle, indicate to the system there is now a planned block in the buffer ready to cycle 
   // start. Otherwise ignore and continue on.
@@ -86,8 +94,13 @@ void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate, int32_t l
 // The arc is approximated by generating a huge number of tiny, linear segments. The chordal tolerance
 // of each segment is configured in settings.arc_tolerance, which is defined to be the maximum normal
 // distance from segment to the circle when the end points both lie on the circle.
+#ifdef USE_LINE_NUMBERS
 void mc_arc(float *position, float *target, float *offset, uint8_t axis_0, uint8_t axis_1, 
   uint8_t axis_linear, float feed_rate, uint8_t invert_feed_rate, float radius, uint8_t isclockwise, int32_t line_number)
+#else
+void mc_arc(float *position, float *target, float *offset, uint8_t axis_0, uint8_t axis_1, 
+  uint8_t axis_linear, float feed_rate, uint8_t invert_feed_rate, float radius, uint8_t isclockwise)
+#endif
 {      
   float center_axis0 = position[axis_0] + offset[axis_0];
   float center_axis1 = position[axis_1] + offset[axis_1];
@@ -183,14 +196,23 @@ void mc_arc(float *position, float *target, float *offset, uint8_t axis_0, uint8
       arc_target[axis_0] = center_axis0 + r_axis0;
       arc_target[axis_1] = center_axis1 + r_axis1;
       arc_target[axis_linear] += linear_per_segment;
+      
+      #ifdef USE_LINE_NUMBERS
       mc_line(arc_target, feed_rate, invert_feed_rate, line_number);
+      #else
+      mc_line(arc_target, feed_rate, invert_feed_rate);
+      #endif
       
       // Bail mid-circle on system abort. Runtime command check already performed by mc_line.
       if (sys.abort) { return; }
     }
   }
   // Ensure last segment arrives at target location.
+  #ifdef USE_LINE_NUMBERS
   mc_line(target, feed_rate, invert_feed_rate, line_number);
+  #else
+  mc_line(target, feed_rate, invert_feed_rate);
+  #endif
 }
 
 

motion_control.h

@@ -24,18 +24,26 @@
 
 #define HOMING_CYCLE_LINE_NUMBER -1
 
-
 // Execute linear motion in absolute millimeter coordinates. Feed rate given in millimeters/second
 // unless invert_feed_rate is true. Then the feed_rate means that the motion should be completed in
 // (1 minute)/feed_rate time.
+#ifdef USE_LINE_NUMBERS
 void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate, int32_t line_number);
+#else
+void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate);
+#endif
 
 // Execute an arc in offset mode format. position == current xyz, target == target xyz, 
 // offset == offset from current xyz, axis_XXX defines circle plane in tool space, axis_linear is
 // the direction of helical travel, radius == circle radius, isclockwise boolean. Used
 // for vector transformation direction.
+#ifdef USE_LINE_NUMBERS
 void mc_arc(float *position, float *target, float *offset, uint8_t axis_0, uint8_t axis_1,
   uint8_t axis_linear, float feed_rate, uint8_t invert_feed_rate, float radius, uint8_t isclockwise, int32_t line_number);
+#else
+void mc_arc(float *position, float *target, float *offset, uint8_t axis_0, uint8_t axis_1,
+  uint8_t axis_linear, float feed_rate, uint8_t invert_feed_rate, float radius, uint8_t isclockwise);
+#endif
   
 // Dwell for a specific number of seconds
 void mc_dwell(float seconds);

planner.c

@@ -259,7 +259,11 @@ uint8_t plan_check_full_buffer()
    is used in three ways: as a normal feed rate if invert_feed_rate is false, as inverse time if
    invert_feed_rate is true, or as seek/rapids rate if the feed_rate value is negative (and
    invert_feed_rate always false). */
+#ifdef USE_LINE_NUMBERS   
 void plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rate, int32_t line_number) 
+#else
+void plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rate) 
+#endif
 {
   // Prepare and initialize new block
   plan_block_t *block = &block_buffer[block_buffer_head];

planner.h

@@ -64,7 +64,11 @@ void plan_reset();
 // Add a new linear movement to the buffer. target[N_AXIS] is the signed, absolute target position 
 // in millimeters. Feed rate specifies the speed of the motion. If feed rate is inverted, the feed
 // rate is taken to mean "frequency" and would complete the operation in 1/feed_rate minutes.
+#ifdef USE_LINE_NUMBERS
 void plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rate, int32_t line_number);
+#else
+void plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rate);
+#endif
 
 // Called when the current block is no longer needed. Discards the block and makes the memory
 // availible for new blocks.