Bug fixes and more limit configurability

- Strange sizeof() bug in the most recent releases. Manifested as an
alarm upon a power up even when homing was disabled. Fixed by declaring
sizeof() with struct types, rather than variable names, even though
they were validated to give the same value.

- Spindle speed zero should disable the spindle. Now fixed.

- New configuration option for inverting certain limit pins. Handy for
mixed NO and NC switch machines. See config.h for details.

- Incremented version and pre-build firmware link.

README.md

@@ -27,7 +27,7 @@ Grbl includes full acceleration management with look ahead. That means the contr
 ***
 
 _**Master Branch:**_
-* [Grbl v0.9j Atmega328p 16mhz 115200baud with generic defaults](http://bit.ly/1I8Ey4S) _(2015-12-18)_
+* [Grbl v0.9j Atmega328p 16mhz 115200baud with generic defaults](http://bit.ly/1I8Ey4S) _(2016-03-03)_
   - **IMPORTANT INFO WHEN UPGRADING TO GRBL v0.9 :** 
   - Baudrate is now **115200** (Up from 9600). 
   - Homing cycle updated. Located based on switch trigger, rather than release point.

doc/log/commit_log_v0.9j.txt

@@ -1,3 +1,19 @@
+----------------
+Date: 2015-12-18
+Author: Sonny Jeon
+Subject: Minor bug fixes.
+
+- Planner was under-estimating maximum speeds through straight
+junctions in certain cases. The calculations have been updated to be
+more accurate.
+
+- Type declaration fix in probe.c.
+
+ - Commit log for v0.9j generated separately from v0.9i’s.
+
+- Incremented version and updated pre-built firmware link.
+
+
 ----------------
 Date: 2015-09-30
 Author: Sonny Jeon

grbl/config.h

@@ -126,8 +126,8 @@
 #define MESSAGE_PROBE_COORDINATES // Enabled by default. Comment to disable.
  
 // 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.
+// analog pin 4. 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.
+// NOTE: The M8 flood coolant control pin on analog pin 3 will still be functional regardless.
 // #define ENABLE_M7 // Disabled by default. Uncomment to enable.
 
 // This option causes the feed hold input to act as a safety door switch. A safety door, when triggered,
@@ -157,6 +157,14 @@
 //   the CONTROL_INVERT_MASK definition in cpu_map.h files.
 // #define INVERT_ALL_CONTROL_PINS // Default disabled. Uncomment to enable.
 
+// Inverts select limit pin states based on the following mask. This effects all limit pin functions, 
+// such as hard limits and homing. However, this is different from overall invert limits setting. 
+// This build option will invert only the limit pins defined here, and then the invert limits setting
+// will be applied to all of them. This is useful when a user has a mixed set of limit pins with both
+// normally-open(NO) and normally-closed(NC) switches installed on their machine.
+// NOTE: PLEASE DO NOT USE THIS, unless you have a situation that needs it.
+// #define INVERT_LIMIT_PIN_MASK ((1<<X_LIMIT_BIT)|(1<<Y_LIMIT_BIT)) // Default disabled. Uncomment to enable.
+
 // Inverts the spindle enable pin from low-disabled/high-enabled to low-enabled/high-disabled. Useful
 // for some pre-built electronic boards.
 // NOTE: If VARIABLE_SPINDLE is enabled(default), this option has no effect as the PWM output and 

grbl/gcode.c

@@ -40,7 +40,7 @@ parser_block_t gc_block;
 
 void gc_init() 
 {
-  memset(&gc_state, 0, sizeof(gc_state));
+  memset(&gc_state, 0, sizeof(parser_state_t));
   
   // Load default G54 coordinate system.
   if (!(settings_read_coord_data(gc_state.modal.coord_select,gc_state.coord_system))) { 
@@ -80,7 +80,7 @@ uint8_t gc_execute_line(char *line)
      values struct, word tracking variables, and a non-modal commands tracker for the new 
      block. This struct contains all of the necessary information to execute the block. */
 
-  memset(&gc_block, 0, sizeof(gc_block)); // Initialize the parser block struct.
+  memset(&gc_block, 0, sizeof(parser_block_t)); // Initialize the parser block struct.
   memcpy(&gc_block.modal,&gc_state.modal,sizeof(gc_modal_t)); // Copy current modes
   uint8_t axis_command = AXIS_COMMAND_NONE;
   uint8_t axis_0, axis_1, axis_linear;

grbl/grbl.h

@@ -23,7 +23,7 @@
 
 // Grbl versioning system
 #define GRBL_VERSION "0.9j"
-#define GRBL_VERSION_BUILD "20151218"
+#define GRBL_VERSION_BUILD "20160303"
 
 // Define standard libraries used by Grbl.
 #include <avr/io.h>

grbl/limits.c

@@ -70,6 +70,9 @@ uint8_t limits_get_state()
 {
   uint8_t limit_state = 0;
   uint8_t pin = (LIMIT_PIN & LIMIT_MASK);
+  #ifdef INVERT_LIMIT_PIN_MASK
+    pin ^= INVERT_LIMIT_PIN_MASK;
+  #endif
   if (bit_isfalse(settings.flags,BITFLAG_INVERT_LIMIT_PINS)) { pin ^= LIMIT_MASK; }
   if (pin) {  
     uint8_t idx;

grbl/main.c

@@ -34,7 +34,7 @@ int main(void)
   stepper_init();  // Configure stepper pins and interrupt timers
   system_init();   // Configure pinout pins and pin-change interrupt
   
-  memset(&sys, 0, sizeof(sys));  // Clear all system variables
+  memset(&sys, 0, sizeof(system_t));  // Clear all system variables
   sys.abort = true;   // Set abort to complete initialization
   sei(); // Enable interrupts
 

grbl/planner.c

@@ -200,7 +200,7 @@ static void planner_recalculate()
 
 void plan_reset() 
 {
-  memset(&pl, 0, sizeof(pl)); // Clear planner struct
+  memset(&pl, 0, sizeof(planner_t)); // Clear planner struct
   block_buffer_tail = 0;
   block_buffer_head = 0; // Empty = tail
   next_buffer_head = 1; // plan_next_block_index(block_buffer_head)

grbl/spindle_control.c

@@ -95,6 +95,8 @@ void spindle_set_state(uint8_t state, float rpm)
         uint8_t current_pwm;
       #endif
 
+      if (rpm <= 0.0) { spindle_stop(); } // RPM should never be negative, but check anyway.
+      else {
         #define SPINDLE_RPM_RANGE (SPINDLE_MAX_RPM-SPINDLE_MIN_RPM)
         if ( rpm < SPINDLE_MIN_RPM ) { rpm = 0; } 
         else { 
@@ -115,13 +117,17 @@ void spindle_set_state(uint8_t state, float rpm)
             SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
           #endif
         #endif
+      }
       
     #else
+      if (rpm <= 0.0) { spindle_stop(); } // RPM should never be negative, but check anyway.
+      else {
         #ifdef INVERT_SPINDLE_ENABLE_PIN
           SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
         #else
           SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
         #endif
+      }
     #endif
 
   }

grbl/stepper.c

@@ -451,8 +451,8 @@ void st_reset()
   st_go_idle();
   
   // Initialize stepper algorithm variables.
-  memset(&prep, 0, sizeof(prep));
+  memset(&prep, 0, sizeof(st_prep_t));
-  memset(&st, 0, sizeof(st));
+  memset(&st, 0, sizeof(stepper_t));
   st.exec_segment = NULL;
   pl_block = NULL;  // Planner block pointer used by segment buffer
   segment_buffer_tail = 0;