diff --git a/README.md b/README.md
index 3b8c5bb..e0d6677 100644
--- a/README.md
+++ b/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.
diff --git a/doc/log/commit_log_v0.9j.txt b/doc/log/commit_log_v0.9j.txt
index 3bf71bb..8c66a42 100644
--- a/doc/log/commit_log_v0.9j.txt
+++ b/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
diff --git a/grbl/config.h b/grbl/config.h
index e8a600b..bd9c0d6 100644
--- a/grbl/config.h
+++ b/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.
-// NOTE: The M8 flood coolant control pin on analog pin 4 will still be functional regardless.
+// 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 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 
diff --git a/grbl/gcode.c b/grbl/gcode.c
index a0a8ad1..c470f67 100644
--- a/grbl/gcode.c
+++ b/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))) { 
@@ -79,8 +79,8 @@ uint8_t gc_execute_line(char *line)
      executed after successful error-checking. The parser block struct also contains a block
      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;
diff --git a/grbl/grbl.h b/grbl/grbl.h
index 52f2525..50f5bf3 100644
--- a/grbl/grbl.h
+++ b/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>
diff --git a/grbl/limits.c b/grbl/limits.c
index 9742a32..90f49ba 100644
--- a/grbl/limits.c
+++ b/grbl/limits.c
@@ -70,12 +70,15 @@ 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;
-	for (idx=0; idx<N_AXIS; idx++) {
-	  if (pin & get_limit_pin_mask(idx)) { limit_state |= (1 << idx); }
-	}
+    uint8_t idx;
+    for (idx=0; idx<N_AXIS; idx++) {
+      if (pin & get_limit_pin_mask(idx)) { limit_state |= (1 << idx); }
+    }
   }
   return(limit_state);
 }
@@ -210,37 +213,37 @@ void limits_go_home(uint8_t cycle_mask)
     
     st_prep_buffer(); // Prep and fill segment buffer from newly planned block.
     st_wake_up(); // Initiate motion
-	do {
-	  if (approach) {
-		// Check limit state. Lock out cycle axes when they change.
-		limit_state = limits_get_state();
-		for (idx=0; idx<N_AXIS; idx++) {
-		  if (axislock & step_pin[idx]) {
-			if (limit_state & (1 << idx)) { axislock &= ~(step_pin[idx]); }
-		  }
-		}
-		sys.homing_axis_lock = axislock;
-	  }
+    do {
+      if (approach) {
+        // Check limit state. Lock out cycle axes when they change.
+        limit_state = limits_get_state();
+        for (idx=0; idx<N_AXIS; idx++) {
+          if (axislock & step_pin[idx]) {
+            if (limit_state & (1 << idx)) { axislock &= ~(step_pin[idx]); }
+          }
+        }
+        sys.homing_axis_lock = axislock;
+      }
 
-	  st_prep_buffer(); // Check and prep segment buffer. NOTE: Should take no longer than 200us.
+      st_prep_buffer(); // Check and prep segment buffer. NOTE: Should take no longer than 200us.
 
-	  // Exit routines: No time to run protocol_execute_realtime() in this loop.
-	  if (sys_rt_exec_state & (EXEC_SAFETY_DOOR | EXEC_RESET | EXEC_CYCLE_STOP)) {
-	    // Homing failure: Limit switches are still engaged after pull-off motion
-		if ( (sys_rt_exec_state & (EXEC_SAFETY_DOOR | EXEC_RESET)) ||  // Safety door or reset issued
-		     (!approach && (limits_get_state() & cycle_mask)) ||  // Limit switch still engaged after pull-off motion
-		     ( approach && (sys_rt_exec_state & EXEC_CYCLE_STOP)) ) { // Limit switch not found during approach.
-     	  mc_reset(); // Stop motors, if they are running.
-		  protocol_execute_realtime();
-		  return;
-		} else {
-		  // Pull-off motion complete. Disable CYCLE_STOP from executing.
+      // Exit routines: No time to run protocol_execute_realtime() in this loop.
+      if (sys_rt_exec_state & (EXEC_SAFETY_DOOR | EXEC_RESET | EXEC_CYCLE_STOP)) {
+        // Homing failure: Limit switches are still engaged after pull-off motion
+        if ( (sys_rt_exec_state & (EXEC_SAFETY_DOOR | EXEC_RESET)) ||  // Safety door or reset issued
+           (!approach && (limits_get_state() & cycle_mask)) ||  // Limit switch still engaged after pull-off motion
+           ( approach && (sys_rt_exec_state & EXEC_CYCLE_STOP)) ) { // Limit switch not found during approach.
+          mc_reset(); // Stop motors, if they are running.
+          protocol_execute_realtime();
+          return;
+        } else {
+          // Pull-off motion complete. Disable CYCLE_STOP from executing.
           bit_false_atomic(sys_rt_exec_state,EXEC_CYCLE_STOP);
-		  break;
-		} 
-	  }
+          break;
+        } 
+      }
 
-	} while (STEP_MASK & axislock);
+    } while (STEP_MASK & axislock);
 
     st_reset(); // Immediately force kill steppers and reset step segment buffer.
     plan_reset(); // Reset planner buffer to zero planner current position and to clear previous motions.
diff --git a/grbl/main.c b/grbl/main.c
index 250baaf..32b2e2b 100644
--- a/grbl/main.c
+++ b/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
 
diff --git a/grbl/planner.c b/grbl/planner.c
index 271fcf4..c0d769d 100644
--- a/grbl/planner.c
+++ b/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)
diff --git a/grbl/spindle_control.c b/grbl/spindle_control.c
index d9c5c10..a98ed23 100644
--- a/grbl/spindle_control.c
+++ b/grbl/spindle_control.c
@@ -50,17 +50,17 @@ void spindle_stop()
     TCCRA_REGISTER &= ~(1<<COMB_BIT); // Disable PWM. Output voltage is zero.
     #if defined(CPU_MAP_ATMEGA2560) || defined(USE_SPINDLE_DIR_AS_ENABLE_PIN)
       #ifdef INVERT_SPINDLE_ENABLE_PIN
-		SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);  // Set pin to high
-	  #else
-		SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT); // Set pin to low
-	  #endif
+        SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);  // Set pin to high
+      #else
+        SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT); // Set pin to low
+      #endif
     #endif
   #else
     #ifdef INVERT_SPINDLE_ENABLE_PIN
-	  SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);  // Set pin to high
-	#else
-	  SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT); // Set pin to low
-	#endif
+      SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);  // Set pin to high
+    #else
+      SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT); // Set pin to low
+    #endif
   #endif  
 }
 
@@ -95,33 +95,39 @@ void spindle_set_state(uint8_t state, float rpm)
         uint8_t current_pwm;
       #endif
 
-      #define SPINDLE_RPM_RANGE (SPINDLE_MAX_RPM-SPINDLE_MIN_RPM)
-      if ( rpm < SPINDLE_MIN_RPM ) { rpm = 0; } 
-      else { 
-        rpm -= SPINDLE_MIN_RPM; 
-        if ( rpm > SPINDLE_RPM_RANGE ) { rpm = SPINDLE_RPM_RANGE; } // Prevent integer overflow
-      }
-      current_pwm = floor( rpm*(PWM_MAX_VALUE/SPINDLE_RPM_RANGE) + 0.5);
-      #ifdef MINIMUM_SPINDLE_PWM
-        if (current_pwm < MINIMUM_SPINDLE_PWM) { current_pwm = MINIMUM_SPINDLE_PWM; }
-      #endif
-      OCR_REGISTER = current_pwm; // Set PWM pin output
+      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 { 
+          rpm -= SPINDLE_MIN_RPM; 
+          if ( rpm > SPINDLE_RPM_RANGE ) { rpm = SPINDLE_RPM_RANGE; } // Prevent integer overflow
+        }
+        current_pwm = floor( rpm*(PWM_MAX_VALUE/SPINDLE_RPM_RANGE) + 0.5);
+        #ifdef MINIMUM_SPINDLE_PWM
+          if (current_pwm < MINIMUM_SPINDLE_PWM) { current_pwm = MINIMUM_SPINDLE_PWM; }
+        #endif
+        OCR_REGISTER = current_pwm; // Set PWM pin output
     
-      // On the Uno, spindle enable and PWM are shared, unless otherwise specified.
-      #if defined(CPU_MAP_ATMEGA2560) || defined(USE_SPINDLE_DIR_AS_ENABLE_PIN) 
+        // On the Uno, spindle enable and PWM are shared, unless otherwise specified.
+        #if defined(CPU_MAP_ATMEGA2560) || defined(USE_SPINDLE_DIR_AS_ENABLE_PIN) 
+          #ifdef INVERT_SPINDLE_ENABLE_PIN
+            SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
+          #else
+            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
-      
-    #else   
-      #ifdef INVERT_SPINDLE_ENABLE_PIN
-		SPINDLE_ENABLE_PORT &= ~(1<<SPINDLE_ENABLE_BIT);
-	  #else
-		SPINDLE_ENABLE_PORT |= (1<<SPINDLE_ENABLE_BIT);
-	  #endif
+      }
     #endif
 
   }
diff --git a/grbl/stepper.c b/grbl/stepper.c
index ce08599..a865e3e 100644
--- a/grbl/stepper.c
+++ b/grbl/stepper.c
@@ -451,8 +451,8 @@ void st_reset()
   st_go_idle();
   
   // Initialize stepper algorithm variables.
-  memset(&prep, 0, sizeof(prep));
-  memset(&st, 0, sizeof(st));
+  memset(&prep, 0, sizeof(st_prep_t));
+  memset(&st, 0, sizeof(stepper_t));
   st.exec_segment = NULL;
   pl_block = NULL;  // Planner block pointer used by segment buffer
   segment_buffer_tail = 0;