Untested! Soft limits, max travel, homing changes, new settings.

- WARNING: Completely untested. Will later when there is time. Settings
WILL be overwritten, as there are new settings.

- Soft limits installed. Homing must be enabled for soft limits to work
correctly. Errors out much like a hard limit, locking out everything
and bringing up the alarm mode. Only difference is it forces a feed
hold before doing so. Position is not lost.

- IMPORTANT: Homing had to be updated so that soft limits work better
with less CPU overhead. When homing completes, all axes are assumed to
exist in negative space. If your limit switch is other side, the homing
cycle with set this axis location to the max travel value, rather than
zero.

- Update mc_line() to accept an array, rather than individual variables.

- Added an mc_auto_cycle_start() function handle this feature.
Organization only.

-

settings.h

@@ -3,7 +3,7 @@
   Part of Grbl
 
   Copyright (c) 2009-2011 Simen Svale Skogsrud
-  Copyright (c) 2011-2012 Sungeun K. Jeon
+  Copyright (c) 2011-2013 Sungeun K. Jeon
   
   Grbl is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -29,7 +29,7 @@
 
 // Version of the EEPROM data. Will be used to migrate existing data from older versions of Grbl
 // when firmware is upgraded. Always stored in byte 0 of eeprom
-#define SETTINGS_VERSION 52
+#define SETTINGS_VERSION 53
 
 // Define bit flag masks for the boolean settings in settings.flag.
 #define BITFLAG_REPORT_INCHES      bit(0)
@@ -37,6 +37,7 @@
 #define BITFLAG_INVERT_ST_ENABLE   bit(2)
 #define BITFLAG_HARD_LIMIT_ENABLE  bit(3)
 #define BITFLAG_HOMING_ENABLE      bit(4)
+#define BITFLAG_SOFT_LIMIT_ENABLE  bit(5)
 
 // Define EEPROM memory address location values for Grbl settings and parameters
 // NOTE: The Atmega328p has 1KB EEPROM. The upper half is reserved for parameters and
@@ -74,7 +75,7 @@ typedef struct {
   uint8_t stepper_idle_lock_time; // If max value 255, steppers do not disable.
   uint8_t decimal_places;
   float max_velocity[N_AXIS];
-//  float mm_soft_limit[N_AXIS];
+  float max_travel[N_AXIS];
 //  uint8_t status_report_mask; // Mask to indicate desired report data.
 } settings_t;
 extern settings_t settings;