v1.1c: New sleep mode. Laser mode and other bug fixes.

- New $SLP sleep mode that will disable spindle, coolant, and stepper
enable pins. Allows users to disable their steppers without having to
alter their settings. A reset is required to exit and re-initializes in
alarm state.

- Laser mode wasn’t updating the spindle PWM correctly (effected
spindle speed overrides) and not checking for modal states either.
Fixed both issues.

- While in laser mode, parking motions are ignored, since the power off
delay with the retract motion would burn the material. It will just
turn off and not move. A restore immediately powers up and resumes. No
delays.

- Changing rpm max and min settings did not update the spindle PWM
calculations. Now fixed.

- Increased default planner buffer from 16 to 17 block. It seems to be
stable, but need to monitor this carefully.

- Removed software debounce routine for limit pins. Obsolete.

- Fixed a couple parking motion bugs. One related to restoring
incorrectly and the other the parking rate wasn’t compatible with the
planner structs.

- Fixed a bug caused by refactoring the critical alarms in a recent
push. Soft limits weren’t invoking a critical alarm.

- Updated the documentation with the new sleep feature and added some
more details to the change summary.

grbl/config.h

@@ -420,7 +420,7 @@
 // available RAM, like when re-compiling for a Mega2560. Or decrease if the Arduino begins to
 // crash due to the lack of available RAM or if the CPU is having trouble keeping up with planning
 // new incoming motions as they are executed.
-// #define BLOCK_BUFFER_SIZE 16 // Uncomment to override default in planner.h.
+// #define BLOCK_BUFFER_SIZE 17 // Uncomment to override default in planner.h.
 
 // Governs the size of the intermediary step segment buffer between the step execution algorithm
 // and the planner blocks. Each segment is set of steps executed at a constant velocity over a
@@ -453,15 +453,6 @@
 // #define RX_BUFFER_SIZE 128 // (1-254) Uncomment to override defaults in serial.h
 // #define TX_BUFFER_SIZE 90  // (1-254)
 
-// A simple software debouncing feature for hard limit switches. When enabled, the interrupt
-// monitoring the hard limit switch pins will enable the Arduino's watchdog timer to re-check
-// the limit pin state after a delay of about 32msec. This can help with CNC machines with
-// problematic false triggering of their hard limit switches, but it WILL NOT fix issues with
-// electrical interference on the signal cables from external sources. It's recommended to first
-// use shielded signal cables with their shielding connected to ground (old USB/computer cables
-// work well and are cheap to find) and wire in a low-pass circuit into each limit pin.
-// #define ENABLE_SOFTWARE_DEBOUNCE // Default disabled. Uncomment to enable.
-
 // Configures the position after a probing cycle during Grbl's check mode. Disabled sets
 // the position to the probe target, when enabled sets the position to the start position.
 // #define SET_CHECK_MODE_PROBE_TO_START // Default disabled. Uncomment to enable.
@@ -548,8 +539,8 @@
 // Configure options for the parking motion, if enabled.
 #define PARKING_AXIS Z_AXIS // Define which axis that performs the parking motion
 #define PARKING_TARGET -5.0 // Parking axis target. In mm, as machine coordinate [-max_travel,0].
-#define PARKING_RATE -1.0 // Parking fast rate after pull-out. In mm/min or (-1.0) for seek rate.
-#define PARKING_PULLOUT_RATE 250.0 // Pull-out/plunge slow feed rate in mm/min.
+#define PARKING_RATE 500.0 // Parking fast rate after pull-out in mm/min.
+#define PARKING_PULLOUT_RATE 100.0 // Pull-out/plunge slow feed rate in mm/min.
 #define PARKING_PULLOUT_INCREMENT 5.0 // Spindle pull-out and plunge distance in mm. Incremental distance.
                                       // Must be positive value or equal to zero.