Planner and printFloat update.

- Planner model update. Improves performance for machines with
different accelerations on each axes. Particularly for 3D carving.

- Print float update to print 13 (from 10) characters. Help reduce
print errors for unusually long floating point values.

doc/log/commit_log_v1.0d.txt

@@ -1,3 +1,13 @@
+----------------
+Date: 2016-04-10
+Author: chamnit
+Subject: Alarm and safety door bug fix.
+
+- Typo in protocol.c caused a safety door to lock out the system during
+an alarm. The correct character should keep that from happening and
+bring back the original door/alarm behavior.
+
+
 ----------------
 Date: 2016-04-04
 Author: Sonny Jeon
@@ -60,31 +70,3 @@ time being. These removal options will go away eventually before they
 become hard-coded in. (They will be toggle-able with the status report
 mask in settings though.)
 
-
-----------------
-Date: 2016-03-19
-Author: Sonny Jeon
-Subject: Removed 328p-related code. Enabled options by default.
-
-- Removed all of the 328p-related code, which seemed to clean up things
-quite a bit without all those ifdefs everywhere.
-
-- Since the 328p was very memory and flash limited, lots of
-compile-time options were disabled by default. These have been now been
-enabled by default. As they are considered generally helpful and does
-not significantly impact how Grbl runs.
-
-- For example, status reports can now report back real time feed rate
-and line number being executed. Variable spindle is standard with a
-separate spindle enable pin. Grbl will now check if a user setting has
-exceeded the maximum step frequency and report an error, if so. And
-finally, M7 flood coolant is enabled.
-
-- In addition, all buffers have been significantly increased to take
-advantage of the additional memory available. The planner buffer can
-plan up to 36 motions. The serial buffers have been doubled in size
-(256/128 bytes RX/TX). And the longest line Grbl can accept is 256
-bytes, per the g-code standard (Grbl 328p is limited to 80).
-
-- Removed the cpu_map folder, since this version is strictly Mega2560.
-

grbl/grbl.h

@@ -23,7 +23,7 @@
 
 // Grbl versioning system
 #define GRBL_VERSION "1.0d"
-#define GRBL_VERSION_BUILD "20160410"
+#define GRBL_VERSION_BUILD "20160510"
 
 // Define standard libraries used by Grbl.
 #include <avr/io.h>

grbl/planner.c

@@ -272,8 +272,6 @@ uint8_t plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rat
   block->line_number = line_number;
 
   // Compute and store initial move distance data.
-  // TODO: After this for-loop, we don't touch the stepper algorithm data. Might be a good idea
-  // to try to keep these types of things completely separate from the planner for portability.
   int32_t target_steps[N_AXIS], position_steps[N_AXIS];
   float unit_vec[N_AXIS], delta_mm;
   uint8_t idx;
@@ -326,7 +324,6 @@ uint8_t plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rat
   if (block->step_event_count == 0) { return(PLAN_EMPTY_BLOCK); } 
   
   // Adjust feed_rate value to mm/min depending on type of rate input (normal, inverse time, or rapids)
-  // TODO: Need to distinguish a rapids vs feed move for overrides. Some flag of some sort.
   if (feed_rate < 0) { feed_rate = SOME_LARGE_VALUE; } // Scaled down to absolute max/rapids rate later
   else if (invert_feed_rate) { feed_rate *= block->millimeters; }
   if (feed_rate < MINIMUM_FEED_RATE) { feed_rate = MINIMUM_FEED_RATE; } // Prevents step generation round-off condition.
@@ -335,23 +332,26 @@ uint8_t plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rat
   // down such that no individual axes maximum values are exceeded with respect to the line direction. 
   // NOTE: This calculation assumes all axes are orthogonal (Cartesian) and works with ABC-axes,
   // if they are also orthogonal/independent. Operates on the absolute value of the unit vector.
-  float inverse_unit_vec_value;
+  float junction_vec[N_AXIS];
   float inverse_millimeters = 1.0/block->millimeters;  // Inverse millimeters to remove multiple float divides	
   float junction_cos_theta = 0.0;
+  float magnitude_junction_vec = 0.0;
   for (idx=0; idx<N_AXIS; idx++) {
     if (unit_vec[idx] != 0) {  // Avoid divide by zero.
       unit_vec[idx] *= inverse_millimeters;  // Complete unit vector calculation
-      inverse_unit_vec_value = fabs(1.0/unit_vec[idx]); // Inverse to remove multiple float divides.
 
       // Check and limit feed rate against max individual axis velocities and accelerations
-      feed_rate = min(feed_rate,settings.max_rate[idx]*inverse_unit_vec_value);
-      block->acceleration = min(block->acceleration,settings.acceleration[idx]*inverse_unit_vec_value);
-
+      block->acceleration = min(block->acceleration,fabs(settings.acceleration[idx]/unit_vec[idx]));
+      feed_rate = min(feed_rate,fabs(settings.max_rate[idx]/unit_vec[idx]));
+      
       // Incrementally compute cosine of angle between previous and current path. Cos(theta) of the junction
       // between the current move and the previous move is simply the dot product of the two unit vectors, 
       // where prev_unit_vec is negative. Used later to compute maximum junction speed.
-      junction_cos_theta -= pl.previous_unit_vec[idx] * unit_vec[idx];
+      junction_cos_theta -= pl.previous_unit_vec[idx]*unit_vec[idx];
     }
+    // Compute junction acceleration vector. Magnitude completed later when necessary.
+    junction_vec[idx] = unit_vec[idx]-pl.previous_unit_vec[idx];
+    magnitude_junction_vec += junction_vec[idx]*junction_vec[idx];
   }
 
   // TODO: Need to check this method handling zero junction speeds when starting from rest.
@@ -386,19 +386,28 @@ uint8_t plan_buffer_line(float *target, float feed_rate, uint8_t invert_feed_rat
        memory in the event of a feedrate override changing the nominal speeds of blocks, which can 
        change the overall maximum entry speed conditions of all blocks.
     */
+    
     // NOTE: Computed without any expensive trig, sin() or acos(), by trig half angle identity of cos(theta).
     if (junction_cos_theta > 0.999999) {
       //  For a 0 degree acute junction, just set minimum junction speed. 
       block->max_junction_speed_sqr = MINIMUM_JUNCTION_SPEED*MINIMUM_JUNCTION_SPEED;
     } else {
-      junction_cos_theta = max(junction_cos_theta,-0.999999); // Check for numerical round-off to avoid divide by zero.
-      float sin_theta_d2 = sqrt(0.5*(1.0-junction_cos_theta)); // Trig half angle identity. Always positive.
-
-      // TODO: Technically, the acceleration used in calculation needs to be limited by the minimum of the
-      // two junctions. However, this shouldn't be a significant problem except in extreme circumstances.
-      block->max_junction_speed_sqr = max( MINIMUM_JUNCTION_SPEED*MINIMUM_JUNCTION_SPEED,
-                     (block->acceleration * settings.junction_deviation * sin_theta_d2)/(1.0-sin_theta_d2) );
-
+      if (junction_cos_theta < -0.999999) {
+        // Junction is a straight line or 180 degrees. Junction speed is infinite.
+        block->max_junction_speed_sqr = SOME_LARGE_VALUE;
+      } else {
+        float junction_acceleration = SOME_LARGE_VALUE;
+        magnitude_junction_vec = sqrt(magnitude_junction_vec); // Complete magnitude calculation.
+        for (idx=0; idx<N_AXIS; idx++) {
+          if (junction_vec[idx] != 0) {  // Avoid divide by zero.
+            junction_acceleration = min( junction_acceleration,
+                  fabs((settings.acceleration[idx]*magnitude_junction_vec)/junction_vec[idx]) );
+          }
+        }
+        float sin_theta_d2 = sqrt(0.5*(1.0-junction_cos_theta)); // Trig half angle identity. Always positive.
+        block->max_junction_speed_sqr = max( MINIMUM_JUNCTION_SPEED*MINIMUM_JUNCTION_SPEED,
+                       (junction_acceleration * settings.junction_deviation * sin_theta_d2)/(1.0-sin_theta_d2) );
+      }
     }
   }
   

grbl/print.c

@@ -145,7 +145,7 @@ void printFloat(float n, uint8_t decimal_places)
   n += 0.5; // Add rounding factor. Ensures carryover through entire value.
     
   // Generate digits backwards and store in string.
-  unsigned char buf[10]; 
+  unsigned char buf[13]; 
   uint8_t i = 0;
   uint32_t a = (long)n;  
   buf[decimal_places] = '.'; // Place decimal point, even if decimal places are zero.