doc/log/commit_log_v0.9g.txt

----------------
Date: 2014-09-05
Author: Sonny Jeon
Subject: Minor bug fix and CPU pin map update.

- Sometime I HATE github. This push is just here to be able to describe
the last two pushes today that had a merging conflict and lost all of
the commit comments before.

- Setting $10 would cause $11 to be the same value. Missed a break
statement in the switch-case. Oops! Now fixed.

- CPU pin map for the future versions of Grbl introduced, but not yet
finalized. Still working on it and it’s subject to change.

- Added a new high-speed machining test g-code routine written by Todd
Fleming. Mills a pocket at 15,000mm/min. Do not use when connected to
your machine! You’ve been warned!


----------------
Date: 2014-09-05
Author: Sonny Jeon
Subject: Updated README.md


----------------
Date: 2014-09-05
Author: Sonny Jeon
Subject: Merge branch 'master' of https://github.com/grbl/grbl

Conflicts:
	README.md


----------------
Date: 2014-08-24
Author: Sonny Jeon
Subject: Merge pull request #472 from BinaryConstruct/edge

Add defaults for OX CNC

----------------
Date: 2014-08-24
Author: BinaryConstruct
Subject: Add defaults for OX CNC


----------------
Date: 2014-08-22
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-22
Author: Sonny Jeon
Subject: Updated build date.


----------------
Date: 2014-08-22
Author: Sonny Jeon
Subject: WPos report bug fix when MPos disabled.


----------------
Date: 2014-08-18
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-17
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-17
Author: Sonny Jeon
Subject: Updated bitly link to master firmware


----------------
Date: 2014-08-17
Author: Sonny Jeon
Subject: Merge branch 'master' into edge


----------------
Date: 2014-08-17
Author: Sonny Jeon
Subject: Final minor updates for master release.

- Updated ShapeOko2 defaults based on machine testing of the basic
model provided by Inventables. (or close to it.) Should be pretty
conservative but much faster than before. For example, X and Y axes are
set at (10x) faster at 5000mm/min. It can run much faster than this,
but this seems like a safe speed for everyone.

- Updated README for master release.

- Added some new settings methods for clearing the EEPROM when changing
versions. Needs some more work, but it should ok for master release.
Should work on it more for the next version.


----------------
Date: 2014-08-13
Author: Sonny Jeon
Subject: Added EEPROM force clear.

- When updating from v0.8, the settings will wipe the startup lines and
build info locations so that it won’t use whatever is already there in
the EEPROM. Parameters (coord offsets) are retained. They should be ok
during an upgrade.


----------------
Date: 2014-08-13
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-13
Author: Sonny Jeon
Subject: G28/30 bug fix. Block '$$' during cycle. SO2 defaults.

- A G28/30 bug would cause it to move to machine coordinate [0,0,0] if
no axis words were sent. It was a typo in the new g-code parser. Fixed
and slightly re-written to be more consistent with the program flow.

- Updated the ShapeOko2 defaults based on testing on the real machine.
A little conservative, but it might change again after some more
testing.

- Now blocks ‘$$’ command during a motion, because the printout takes
too long and can starve the segment buffer.


----------------
Date: 2014-08-08
Author: Sonny Jeon
Subject: XON/XOFF flow control variable typo.


----------------
Date: 2014-08-07
Author: Sonny Jeon
Subject: Moved Grbl Sim to its own repo.


----------------
Date: 2014-08-07
Author: Sonny Jeon
Subject: Updated licensing


----------------
Date: 2014-08-05
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-05
Author: Sonny Jeon
Subject: Fixed bug related to very very low feed rates.

- A very very low feed rate command like `G1 X100 F0.01`  would cause
some floating-point round-off error and freeze Grbl into an infinite
loop. To fix it, introduced a MINIMUM_FEED_RATE parameter in config.h
to ensure motions always complete.

- MINIMUM_FEED_RATE is set at 1.0 mm/min by default. It’s recommended
that no rates are below this value, but 0.1mm/min may be ok in some
situations.


----------------
Date: 2014-08-04
Author: Sonny Jeon
Subject: Allow '$$' in check mode.

- Now allows the ‘$$’ view Grbl settings while in check mode

- Updated the version build date


----------------
Date: 2014-08-04
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-04
Author: Sonny Jeon
Subject: Fixed probe position sync error.

- Restored probe position syncing. Had removed a pull-off motion after
a probe cycle completes, but ended up de-synchronizing the g-code
parser and probing cycle positions. Putting the pull-off motion back
fixed the problem.


----------------
Date: 2014-08-03
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-03
Author: Sonny Jeon
Subject: Probing cycle and view build info bug fixes.

- Probing cycle would drop into a QUEUED state, if multiple G38.2 are
sent. It would not honor the auto cycle start flags. To fix, the auto
cycle start state is saved at the beginning of the probing cycle and
restored at the end, since the feed hold it uses to stop a triggered
probe will disable the auto start flag. For now it’s a patch, rather
than a permanent fix.

- protocol_buffer_synchronize() also has a failure case. Auto cycle
start does not get executed when the system is waiting in here, so if
it’s in a QUEUED state already, it won’t resume. Patched here, but not
fully resolved.

- Fixed a problem with the “view build info” command. The EEPROM write
would do weird things and corrupt the EEPROM. Not sure exactly what
caused it, but it’s likely a compiler problem with an improperly
defined EEPROM address. It didn’t have enough room to store a full
string. To fix, the build info EEPROM range was increased and the max
number of STARTUP_BLOCKS was reduced to 2 from 3.

- Lastly, when a $I view build info is used for the first time, it
would normally show an EEPROM read error, since it wasn’t cleared or
wasn’t therein the first place. It will now not show that error. A
patch rather than a permanent fix again.


----------------
Date: 2014-08-01
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-08-01
Author: Sonny Jeon
Subject: Minor bug fixes.

- Bug fix for step and direction invert masks not immediately being in
effect. Now regenerates the masks when a user changes this setting.

- Bug fix for probing cycle. G-code standard mandates that there is an
error if the probe is already triggered when the cycle is commanded.
However, Grbl may have motions to pull off a previous probing cycle in
queue and can falsely lead to errors. To fix this, the triggered check
is performed within the probing cycle itself, right after the planner
buffer is synced. If there is an error, it will now alarm out as a
probe fail.


----------------
Date: 2014-07-28
Author: Sonny Jeon
Subject: Compile in Atmel Studio fix.


----------------
Date: 2014-07-28
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-07-27
Author: Sonny Jeon
Subject: Added build info feedback in help

- `$I` prints the Grbl build info and version number. NOTE: `$I=xxx`
stores an additional 30 character string into EEPROM, which will be
printed with the build info the next time it’s run. This is for
identification purposes for users that have more than one system using
Grbl.


----------------
Date: 2014-07-26
Author: Sonny Jeon
Subject: Updates to allow Arduino IDE direct compiling.

- Only minor changes were required to make the Arduino IDE compile all
of the Grbl’s source code (correctly using the C-compiler). Tested in
Windows and Mac and with the normal USB upload and with a programmer.


----------------
Date: 2014-07-26
Author: Sonny Jeon
Subject: Settings refactoring. Bug fixes. Misc new features.

This is likely the last major change to the v0.9 code base before push
to master. Only two minor things remain on the agenda (CoreXY support,
force clear EEPROM, and an extremely low federate bug).

- NEW! Grbl is now compile-able and may be flashed directly through the
Arduino IDE. Only minor changes were required for this compatibility.
See the Wiki to learn how to do it.

- New status reporting mask to turn on and off what Grbl sends back.
This includes machine coordinates, work coordinates, serial RX buffer
usage, and planner buffer usage. Expandable to more information on user
request, but that’s it for now.

- Settings have been completely renumbered to allow for future new
settings to be installed without having to constantly reshuffle and
renumber all of the settings every time.

- All settings masks have been standardized to mean bit 0 = X, bit 1 =
Y, and bit 2 = Z, to reduce confusion on how they work. The invert
masks used by the internal Grbl system were updated to accommodate this
change as well.

- New invert probe pin setting, which does what it sounds like.

- Fixed a probing cycle bug, where it would freeze intermittently, and
removed some redundant code.

- Homing may now be set to the origin wherever the limit switches are.
Traditionally machine coordinates should always be in negative space,
but when limit switches on are on the opposite side, the machine
coordinate would be set to -max_travel for the axis. Now you can always
make it [0,0,0] via a compile-time option in config.h. (Soft limits
routine was updated to account for this as well.)

 - Probe coordinate message immediately after a probing cycle may now
be turned off via a compile-time option in config.h. By default the
probing location is always reported.

- Reduced the N_ARC_CORRECTION default value to reflect the changes in
how circles are generated by an arc tolerance, rather than a fixed arc
segment setting.

- Increased the incoming line buffer limit from 70 to 80 characters.
Had some extra memory space to invest into this.

- Fixed a bug where tool number T was not being tracked and reported
correctly.

- Added a print free memory function for debugging purposes. Not used
otherwise.

- Realtime rate report should now work during feed holds, but it hasn’t
been tested yet.

- Updated the streaming scripts with MIT-license and added the simple
streaming to the main stream.py script to allow for settings to be sent.

- Some minor code refactoring to improve flash efficiency. Reduced the
flash by several hundred KB, which was re-invested in some of these new
features.


----------------
Date: 2014-07-17
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-07-12
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-07-12
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-07-12
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-07-12
Author: Sonny Jeon
Subject: Updated README


----------------
Date: 2014-07-11
Author: Sonny Jeon
Subject: Updated README


----------------
Date: 2014-07-11
Author: Sonny Jeon
Subject: Merge pull request #441 from ashelly/edge-simfix

Fixes for simulator in alternate configurations.

----------------
Date: 2014-07-10
Author: ashelly
Subject: Restore changes made only for testing.


----------------
Date: 2014-07-10
Author: ashelly
Subject: Bug fixes for timers, added some wdt support for limit debounce.

- Typo in timer def,
- Handle 8 bit timers correctly,
- Don't skip TOP count in CTC mode
- added SREG for atomic bit operations


----------------
Date: 2014-07-09
Author: Sonny Jeon
Subject: Merge branch 'dev' into edge

Conflicts:
	sim/simulator.c
	sim/simulator.h


----------------
Date: 2014-07-09
Author: Sonny Jeon
Subject: Added test g-code programs.


----------------
Date: 2014-07-06
Author: Sonny Jeon
Subject: Version and build update.

- Incremented from v0.9e to v0.9f due to the new g-codes, velocity
reporting option, decimal printing refactoring, grbl-sim updates, and
G0/G1 bug fix.

- Settings version was also incremented since settings.decimal_places
is now gone.


----------------
Date: 2014-07-06
Author: Sonny Jeon
Subject: Isolate atomic bit flag for execution.

- Denoted bit_true_atomic only for sys.execute bit settings. All other
bit_true type calls are for local variables only and don’t need atomic
access. Still looking into other ways of setting these flags without
requiring atomic access, but this is a patch for now.


----------------
Date: 2014-07-06
Author: Sonny Jeon
Subject: Merge pull request #436 from kfoltman/dev

Fixed atomic access to flags in sys.execute.

----------------
Date: 2014-07-06
Author: Sonny Jeon
Subject: Syntax fix for gcode.c

- Whoops! Missed a bracket and it wasn’t compiling. Now fixed.

- Updated the unsupported gcodes listed at the end of the gcode.c file.


----------------
Date: 2014-07-06
Author: Sonny Jeon
Subject: G43.1/G49 tool length offset installed. Minor bug fix.

- Minor bug fix that caused G92.1 not to work. The mantissa of G92.1
was not computed correctly due to floating point round-off errors and
the use of trunc(). Fixed it by changing the computation with round().

- Installed tool length offsets with G43.1 and G49! True tool length
offsets via G43 are not supported, because these require us to store
tool data that we don’t have space for. But we’ve come up with a good
solution for users that need this. Instead we are strictly using the
dynamic version G43.1 via linuxcnc.org. Visit their website for more
details on the command.

- G43.1 operates by requiring an axis word and value to offset the
configured tool length axis, which can be configured for any axis
(default Z-axis) in config.h. For example, ```G43.1 Z0.5``` will offset
the work coordinates from Z0.0 to Z-0.5.

- G49 will cancel the last tool length offset value and reset it to
zero.

- Tweaked the ‘$#’ parameters report. `Probe` is now `PRB` and a new
value `TLO` states the tool length offset value.


----------------
Date: 2014-07-05
Author: Sonny Jeon
Subject: Merge branch 'ashelly-sim-update' into dev


----------------
Date: 2014-07-05
Author: Sonny Jeon
Subject: Merge grbl-sim updates for v0.9.

- Removed some conflicting code in the main Grbl firmware source.

- Temporary patch for coolant and spindle control with streaming
applied.


----------------
Date: 2014-07-05
Author: Sonny Jeon
Subject: New G43.1/G49 gcodes. Not working yet!!

- Pushed this uncompleted code to merge a conflicting pull request.

- New G43.1 and G49 g-codes to be installed. The beginnings of it are
in place. These g-codes are intended to be used in conjunction with
probing and allow GUIs to set tool length offsets without Grbl needing
to store a tool table.

- G43.1 is defined as a dynamic tool length offset that is not stored
in memory. Rather, when commanded, these are applied to the work
coordinates until a reset or disabled by G49. This works much like G92.


----------------
Date: 2014-07-05
Author: ashelly
Subject: formatting

----------------
Date: 2014-07-05
Author: ashelly
Subject: Update readme.md

----------------
Date: 2014-07-04
Author: ashelly
Subject: Don't need kbhit.h

----------------
Date: 2014-07-04
Author: Adam Shelly
Subject: minor tweaks for mingw.


----------------
Date: 2014-07-04
Author: Sonny Jeon
Subject: Realtime rate reporting. Updated decimal places.

- Added a new optional compile-time feature for ‘realtime’ (within
50ms) feed rate reporting. When querying for a status report, a new
data value will state the current operating rate. It’s only beta at the
moment and has some kinks to work out.

- Updated the code for printing floating point values to N decimal
places. Generalized the main floating point print code to accept a new
decimal places value and created a set of handler functions to print
certain floating point value types used in Grbl, like position, rates,
coordinate offsets, etc. All of these have different decimal
requirements and change when printed in mm or inches mode.

- Number of decimal places for the different value types can be
re-defined in config.h, but there shouldn’t be a need for this, as
these are physically limited.

- Removed the decimal places settings, as this was now obsoleted by the
new decimal places code.

- The new decimal places code also saves almost 300kB in flash space,
as it’s more efficient.


----------------
Date: 2014-07-04
Author: ashelly
Subject: reduce diffs with dev branch


----------------
Date: 2014-07-04
Author: ashelly
Subject: Total rework of simulator for dev branch.  Create separate thread for interrupt processes.  Tick-accurate simulation of timers.  Non-blocking character input for running in realtime mode. Decouple hardware sim from grbl code as much as possible. Expanded command line options. Provisions for cross-platform solution.


----------------
Date: 2014-07-03
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-07-03
Author: Sonny Jeon
Subject: G18 reporting bug fix.

- G18 wasn’t getting reported back to the user correctly, even though
it has been set internally. Fixed the reporting code to reflect this
accurately.


----------------
Date: 2014-07-03
Author: Sonny Jeon
Subject: G-code parser G0/G1 bug fix.

- Although stated as invalid in the NIST g-code standard, most g-code
parsers, including linuxcnc, allow G0 and G1 to be commanded without
axis words present. For example, something like ‘G1 F100.0’ to preset
the motion mode and feed rate without a motion commanded. Older CNC
controllers actually required this for feed rate settings. This update
should now allow this type of behavior.


----------------
Date: 2014-07-02
Author: Sonny Jeon
Subject: Minor bug fixes and updates. Line number tracking.

- Line number tracking was getting truncated at 255, since it was using
wrong variable type. Fixed it with a trunc().

- Increased the max number line allowed by Grbl to 9999999 from the
g-code standard 99999. The latter seems to be an arbitrary number, so
we are allowing larger ones for at least one known use case scenario.

- Created a new test directory to contain some testing g-code to proof
the firmware. Only got started with one test case so far. More will be
inserted as needed.

- Some other commenting updates to clarify certain aspects of the code.


----------------
Date: 2014-06-26
Author: Krzysztof Foltman
Subject: Fixed atomic access to flags in sys.execute.

This seems to fix the bug that caused Grbl to hang during some operations,
especially jogging.


----------------
Date: 2014-05-31
Author: Sonny Jeon
Subject: Arc error-checking update.

- Updated offset-mode arc error-checking to EMC2’s version: The old
NIST definition required the radii to the current location and target
location to differ no more than 0.002mm. This proved to be problematic
and probably why LinuxCNC(EMC2) updated it to be 0.005mm AND 0.1%
radius OR 0.5mm.


----------------
Date: 2014-05-31
Author: Sonny Jeon
Subject: Various minor g-code parser fixes.

- Updated the mantissa calculation that checks for non-integer values
and GXX.X commands that aren’t supported. There was a potential uint8
overflow issue.

- Fixed g-code parser bug related to not using the correct modal
struct. G10 P0 not selecting the current coordinate system when a
G55-59 is issued in the same line.

- Fixed g-code parser bug related to not using the correct modal
struct. Target position locations were not computed correctly when
G90/91 distance modes were changed in the same line. It was using the
previous state, rather than the current block.


----------------
Date: 2014-05-29
Author: Sonny Jeon
Subject: Fixed spindle/coolant/dwell state check.


----------------
Date: 2014-05-25
Author: Sonny Jeon
Subject: Major g-code parser overhaul. 100%* compliant. Other related updates.

- Completely overhauled the g-code parser. It’s now 100%* compliant. (*
may have some bugs). Being compliant, here are some of the major
differences.

- SMALLER and JUST AS FAST! A number of optimizations were found that
sped things up and allowed for the more thorough error-checking to be
installed without a speed hit. Trimmed a lot of ‘fat’ in the parser and
still was able to make it significantly smaller than it was.

- No default feed rate setting! Removed completely! This doesn’t exist
in the g-code standard. So, it now errors out whenever it’s undefined
for motions that require it (G1/2/3/38.2).

- Any g-code parser error expunges the ENTIRE block. This means all
information is lost and not passed on to the running state. Before some
of the states would remain, which could have led to some problems.

- If the g-code block passes all of the error-checks, the g-code state
is updated and all motions are executed according to the order of
execution.

- Changes in spindle speed, when already running, will update the
output pin accordingly. This fixes a bug, where it wouldn’t update the
speed.

- Update g-code parser error reporting. Errors now return detailed
information of what exact went wrong. The most common errors return a
short text description. For less common errors, the parser reports
‘Invalid gcode ID:20’, where 20 is a error ID. A list of error code IDs
and their descriptions will be documented for user reference elsewhere
to save flash space.

- Other notable changes:

- Added a print integer routine for uint8 variables. This saved
significant flash space by switching from a heavier universal print
integer routine.

- Saved some flash space with our own short hypotenuse calculation

- Some arc computation flash and memory optimizations.


----------------
Date: 2014-05-18
Author: Jens Geisler
Subject: Merge pull request #408 from chamnit/master

MIT-Licensing change.

----------------
Date: 2014-05-18
Author: Sonny Jeon
Subject: MIT-licensing change.


----------------
Date: 2014-05-18
Author: Sonny Jeon
Subject: MIT-licensing change


----------------
Date: 2014-04-28
Author: Sonny Jeon
Subject: Merge pull request #391 from paulkaplan/master

Update Shapeoko 2 defaults

----------------
Date: 2014-04-14
Author: Paul Kaplan
Subject: updated shapeoko2 defaults


----------------
Date: 2014-03-14
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-03-13
Author: Sonny Jeon
Subject: Comment corrections and function call update.


----------------
Date: 2014-03-13
Author: Sonny Jeon
Subject: Merge pull request #373 from EliteEng/dev

Added Probing to Mega2560 and fixed Shapeoko2 compile error

----------------
Date: 2014-03-11
Author: Rob Brown
Subject: Added Probing to Mega2560 and fixed Shapeoko2 compile error


----------------
Date: 2014-03-07
Author: henols
Subject: Probing command gets stuck in hold if several g38.2 are submitted
Ex.
G0 X0 Y0 Z0
G38.2 Z-10 F100
G10 L20 P0 Z0
G0 Z2
G38.2 Z-1 F50
G10 L20 P0 Z0
G0 Z2
G0 X0 Y0
G38.2 Z-1 F100
G0 Z2


----------------
Date: 2014-03-10
Author: Sonny Jeon
Subject: Merge pull request #372 from martinstingl/master

Corrected units of default acceleration values

----------------
Date: 2014-03-10
Author: Martin Stingl
Subject: Corrected units of default acceleration values


----------------
Date: 2014-03-07
Author: Sonny Jeon
Subject: Merge pull request #368 from henols/dev

Probing command gets stuck in hold if several g38.2 are submitted

----------------
Date: 2014-03-07
Author: henols
Subject: Probing command gets stuck in hold if several g38.2 are submitted
Ex.
G0 X0 Y0 Z0
G38.2 Z-10 F100
G10 L20 P0 Z0
G0 Z2
G38.2 Z-1 F50
G10 L20 P0 Z0
G0 Z2
G0 X0 Y0
G38.2 Z-1 F100
G0 Z2


----------------
Date: 2014-02-28
Author: Sonny Jeon
Subject: G38.2 probe feature rough draft installed. Working but needs testing.

- G38.2 straight probe now supported. Rough draft. May be tweaked more
as testing ramps up.

- G38.2 requires at least one axis word. Multiple axis words work too.
When commanded, the probe cycle will move at the last ‘F’ feed rate
specified in a straight line.

- During a probe cycle: If the probe pin goes low (normal high), Grbl
will record that immediate position and engage a feed hold. Meaning
that the CNC machine will move a little past the probe switch point, so
keep federates low to stop sooner. Once stopped, Grbl will issue a move
to go back to the recorded probe trigger point.

- During a probe cycle: If the probe switch does not engage by the time
the machine has traveled to its target coordinates, Grbl will issue an
ALARM and the user will be forced to reset Grbl. (Currently G38.3 probe
without error isn’t supported, but would be easy to implement later.)

- After a successful probe, Grbl will send a feedback message
containing the recorded probe coordinates in the machine coordinate
system. This is as the g-code standard on probe parameters specifies.

- The recorded probe parameters are retained in Grbl memory and can be
viewed with the ‘$#’ print parameters command. Upon a power-cycle, not
a soft-reset, Grbl will re-zero these values.

- Moved ‘$#’ command to require IDLE or ALARM mode, because it accesses
EEPROM to fetch the coordinate system offsets.

- Updated the Grbl version to v0.9d.

- The probe cycle is subject to change upon testing or user-feedback.


----------------
Date: 2014-02-27
Author: Sonny Jeon
Subject: Probe cycle line numbers ifdef fixes to get it to compile.

- Updated some of the ifdefs when disabling line numbers feature.
Getting messy with this compile-time option. This will likely get
cleaned up later.

- This is just a push to get the new probing code to compile. Testing
and optimization of the code will soon follow and be pushed next.


----------------
Date: 2014-02-27
Author: Sonny Jeon
Subject: Merge pull request #362 from robgrz/dev

Minimal probing cycle working.  Supports both G38.2 for error and G38.3 ...

----------------
Date: 2014-02-26
Author: Sonny Jeon
Subject: Added grbl planner Matlab simulator for test reference. Updated line number compile-time option.

- Added a grbl planner simulation tool that was written in Matlab and
Python. It was used to visualize the inner workings of the planner as a
program is streamed to it. The simulation assumes that the planner
buffer is empty, then filled, and kept filled. This is mainly for users
to see how the planner works.

- Updated some of the compile-time ifdefs when enabling line numbers.
The leaving the un-used line numbers in the function calls eats a
non-neglible amount of flash memory. So the new if-defs remove them.


----------------
Date: 2014-02-25
Author: Robert Grzesek
Subject: Minimal probing cycle working.  Supports both G38.2 for error and G38.3 when no errors are desired.


----------------
Date: 2014-02-19
Author: Sonny Jeon
Subject: Minor updates to line number feature.

- Changed line number integer types from unsigned to signed int32.
G-code mandates values cannot exceed 99999. Negative values can be used
to indicate certain modes.

- Homing cycle line number changed to -1, as an indicator.

- Fixed a reporting define for the spindle states that was broken by
the last merge.


----------------
Date: 2014-02-19
Author: Sonny Jeon
Subject: Merge pull request #356 from robgrz/dev

Line number reporting as compile-time option.

----------------
Date: 2014-02-19
Author: Sonny Jeon
Subject: Commenting updates. Minor bug fix with exit of soft limit event.


----------------
Date: 2014-02-18
Author: Robert Grzesek
Subject: Merge commit 'cd71a90ce8a770e0030ed6c9bac805b89724e275' into dev

Conflicts:
	limits.c
	motion_control.c
	report.c


----------------
Date: 2014-02-15
Author: Sonny Jeon
Subject: Homing and feed hold bug fixes.

WARNING: Bugs may still exist. This branch is a work in progress and
will be pushed to the edge branch when at beta stability. Use at your
own risk.

- Homing freezing issue fixed. Had to do with the cycle stop flag being
set incorrectly after the homing cycles and before the pull-off
maneuver. Now resets the stepper motors before this can happen.

- Fixed an issue with a rare feed hold failure. Had to do with feed
hold ending exactly at the end of a block. The runtime protocol now
sets the QUEUED and IDLE states appropriately when this occurs. Still
need to clean this code up however, as it’s patched rather than written
well.

- Updated version build via $I command.

- Forgot to comment on a new feature for the last commit. Since steps
are integers and millimeters traveled are floats, the old step segment
generator ignored the step fraction differences in generating the
segment velocities. Didn’t see like it would be much of a big deal, but
there were instances that this would be a problem, especially for very
slow feed rates. The stepper algorithm now micro-adjusts the segment
velocities based on the step fractions not executed from the previous
segment. This ensures that Grbl generates the velocity profiles EXACTLY
and noticeably improves overall acceleration performance.


----------------
Date: 2014-02-09
Author: Sonny Jeon
Subject: Refactoring and lots of bug fixes. Updated homing cycle.

WARNING: There are still some bugs to be worked out. Please use caution
if you test this firmware.

- Feed holds work much better, but there are still some failure
conditions that need to be worked out. This is the being worked on
currently and a fix is planned to be pushed next.

- Homing cycle refactoring: Slight adjustment of the homing cycle to
allow for limit pins to be shared by different axes, as long as the
shared limit pins are not homed on the same cycle. Also, removed the
LOCATE_CYCLE portion of the homing cycle configuration. It was
redundant.

- Limit pin sharing: (See above). To clear up one or two limit pins for
other IO, limit pins can now be shared. For example, the Z-limit can be
shared with either X or Y limit pins, because it’s on a separate homing
cycle. Hard limit will still work exactly as before.

- Spindle pin output fixed. The pins weren’t getting initialized
correctly.

- Fixed a cycle issue where streaming was working almost like a single
block mode. This was caused by a problem with the spindle_run() and
coolant_run() commands and issuing an unintended planner buffer sync.

- Refactored the cycle_start, feed_hold, and other runtime routines
into the runtime command module, where they should be handled here
only. These were redundant.

- Moved some function calls around into more appropriate source code
modules.

- Fixed the reporting of spindle state.


----------------
Date: 2014-02-06
Author: Robert Grzesek
Subject: Made line number reporting optional via config.h


----------------
Date: 2014-02-06
Author: Robert Grzesek
Subject: Initial line number reporting


----------------
Date: 2014-02-02
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-01-28
Author: Jens Geisler
Subject: Merge pull request #337 from michmerr/edge

Make sure that cycle_start state is set before simulating steps.

----------------
Date: 2014-01-28
Author: michmerr
Subject: Simplify setting of STATE_CYCLE and ISR interval.

Set sys.state to STATE_CYCLE directly instead of calling back to
st_wakeup().

Convert get_step_time() to a constant and rename it to ISR_INTERVAL.


----------------
Date: 2014-01-22
Author: michmerr
Subject: Make sure that cycle_start state is set before simulating steps.


----------------
Date: 2014-01-15
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-01-14
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-01-10
Author: Sonny Jeon
Subject: Lots of re-organization and cleaning-up. Some bug fixes.

- Added a new source and header file called system. These files contain
the system commands and variables, as well as all of the system headers
and standard libraries Grbl uses. Centralizing some of the code.

- Re-organized the include headers throughout the source code.

- ENABLE_M7 define was missing from config.h. Now there.

- SPINDLE_MAX_RPM and SPINDLE_MIN_RPM now defined in config.h. No
uncommenting to prevent user issues. Minimum spindle RPM now provides
the lower, near 0V, scale adjustment, i.e. some spindles can go really
slow so why use up our 256 voltage bins for them?

- Remove some persistent variables from coolant and spindle control.
They were redundant.

- Removed a VARIABLE_SPINDLE define in cpu_map.h that shouldn’t have
been there.

- Changed the DEFAULT_ARC_TOLERANCE to 0.002mm to improve arc tracing.
Before we had issues with performance, no longer.

- Fixed a bug with the hard limits and the software debounce feature
enabled. The invert limit pin setting wasn’t honored.

- Fixed a bug with the homing direction mask. Now is like it used to
be. At least for now.

- Re-organized main.c to serve as only as the reset/initialization
routine. Makes things a little bit clearer in terms of execution
procedures.

- Re-organized protocol.c as the overall master control unit for
execution procedures. Not quite there yet, but starting to make a
little more sense in how things are run.

- Removed updating of old settings records. So many new settings have
been added that it’s not worth adding the code to migrate old user
settings.

- Tweaked spindle_control.c a bit and made it more clear and consistent
with other parts of Grbl.

- Tweaked the stepper disable bit code in stepper.c. Requires less
flash memory.


----------------
Date: 2014-01-05
Author: Sonny Jeon
Subject: Updates to some stepper algorithm commenting


----------------
Date: 2014-01-05
Author: Sonny Jeon
Subject: New build info feature. (per @Analogreality request)

- New build info feature. Hidden command ‘$I’ will print the build info
for your Grbl firmware. Users may also write an identifying message
within it via ‘$I=‘ with up to 32 characters. (no more, or else it will
break).

- Adjusted the max number of startup lines to 3. Majority of people
will only need one.

- Fixed a compile error with spindle_control.c. A rogue #endif was
causing problems.


----------------
Date: 2014-01-04
Author: Sonny Jeon
Subject: Variable spindle output. Resolved conflicts in last push.

Resolve conflicts.


----------------
Date: 2014-01-04
Author: Sonny Jeon
Subject: Cleaned up variable spindle output (PWM). Code and config comments.

- Variable spindle speed output as a configuration option. Thanks
@EliteEng! When enabled, the Z-limit (D11) and spindle enable(D12) pins
switch to allow access to the hardware PWM output on pin D11.
Otherwise, everything should work as it does.

- Removed option for inverting the spindle and coolant enable pins.
This is a safety hazard, especially for the spindle. When Grbl
initializes, all pins are momentarily low until it finishes booting. If
an invert is enabled, this means the spindles can be energized briefly
during this time. If users need signal inversion, it’s recommended to
just wire in an inversion circuit instead.

- Cleared out references to spindle variable output in terms of step
signal. This isn’t complete and requires more deliberation before
installing.

- Cleared up and cleaned up some code and config comments.


----------------
Date: 2014-01-03
Author: Sonny Jeon
Subject: Merge pull request #322 from EliteEng/dev

Update to fix compile error

----------------
Date: 2014-01-03
Author: Rob Brown
Subject: Update to fix compile error

Update to fix compile error


----------------
Date: 2014-01-02
Author: Sonny Jeon
Subject: Merge pull request #318 from EliteEng/dev

PWM Spindle Control and Invert Spindle & Coolant Pins

----------------
Date: 2014-01-03
Author: Rob Brown
Subject: Update spindle_control.c

Updated spindle_control.c due to compile error.

----------------
Date: 2014-01-02
Author: Sonny Jeon
Subject: Fix for M7/8/9 modal group checks. Updated AMASS frequency cutoffs and code cleaned.

- Updated Grbl version to 0.9c and build number.

- G-code parser was missing modal group violation checks for M7/8/9
commands. Added them.

- Updated the Adaptive Multi-Axis Step Smoothing (AMASS) cutoff
frequencies so that the trade between the 16-bit Timer1 accuracy and
the level step smoothing are somewhat better balanced. (Smoothing isn’t
free, but a higher accuracy timer would provide high cutoff
frequencies.)


----------------
Date: 2014-01-02
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2014-01-02
Author: Rob Brown
Subject: PWM Spindle Control and Invert Spindle & Coolant Pins

PWM Spindle Control and Invert Spindle & Coolant Pins


----------------
Date: 2013-12-30
Author: Sonny Jeon
Subject: Minor bug fixes: Homing travel calculations. Cycle resuming after spindle and dwell commands.

- Homing travel calculations fixed. It was computing the min travel
rather than max.

- Auto-start disable and pausing after spindle or dwell commands.
Related to plan_synchronize() function call. Now fixed, but still need
to work on the system state.

- Pushed a fix to make this branch more Arduino IDE compatible. Removed
extern call in nuts_bolts.c

- Updated the stepper configuration option of enabling or disabling the
new Adaptive Multi-Axis Step Smoothing Algorithm. Now works either way.

- Updated some copyright info.


----------------
Date: 2013-12-30
Author: Sonny Jeon
Subject: Merge pull request #201 from Protoneer/master

Made a few changes to make the code compatible with the Arduino IDE. Sorry about the tardiness!

----------------
Date: 2013-12-30
Author: Sonny Jeon
Subject: Incomplete push but working. Lots more stuff. More to come.

- NEW! An active multi-axis step smoothing algorithm that automatically
adjusts dependent on step frequency. This solves the long standing
issue to aliasing when moving with multiple axes. Similar in scheme to
Smoothieware, but more advanced in ensuring a more consistent CPU
overhead throughout all frequencies while maintaining step exactness.

- Switched from Timer2 to Timer0 for the Step Port Reset Interrupt.
Mainly to free up hardware PWM pins.

- Seperated the direction and step pin assignments, so we can now move
them to seperate ports. This means that we can more easily support 4+
axes in the future.

- Added a setting for inverting the limit pins, as so many users have
request. Better late than never.

- Bug fix related to EEPROM calls when in cycle. The EEPROM would kill
the stepper motion. Now protocol mandates that the system be either in
IDLE or ALARM to access or change any settings.

- Bug fix related to resuming the cycle after a spindle or dwell
command if auto start has been disabled. This fix is somewhat temporary
or more of a patch. Doesn’t work with a straight call-response
streaming protocol, but works fine with serial buffer pre-filling
streaming that most clients use.

- Renamed the pin_map.h to cpu_map.h to more accurately describe what
the file is.

- Pushed an auto start bug fix upon re-initialization.

- Much more polishing to do!


----------------
Date: 2013-12-29
Author: Sonny Jeon
Subject: Incomplete dev code push, but working. Lots of updates/fixes/improvements. Much still to polish.

- Ugh. Github just erased my list of improvements and changes due to a
conflict and forcing me to resolve it. Hope this goes through.

- Major stepper algorithm change. Trashed the old v0.9 edge
branch-style stepper algorithm. It’s fine, but it was susceptible to
aliasing noise when moving very slow or very fast. It also had a bit of
CPU overhead. It was written to solve a standing issue with v0.8
master, where it couldn’t generate a smooth acceleration abocve
10-15kHz. But, with new step segment buffer in v0.9c, it inadvertently
fixed the acceleration problem with v0.8 stepper algorithm. So, what
does it mean for you? Smoother stepper pulses and likely higher step
frequencies.

- Stepper algorithm now uses Timer1 and Timer2, instead of Timer0 and
Timer2. Timers 0 and 2 can be swapped if there is an issue.

- With the old v0.8 stepper algorithm, the STEP_DELAY_PULSE
configuration option is also back.

- NEW! Hard limit software debouncing. Grbl now employs the AVR’s
watchdog timer as a way to monitor the hard limit pins and checking
their states after a delay. This is a simple software debouncing
technique and may help alleviate some of the false trigger some users
have been complaining about. BUT, this won’t fix electric noise issues!

- Fixed an issue with the new homing cycle routine where it wasn’t
honoring the acceleration and axis speed limits depending on the homing
cycle mask. Now does. Also, updated the homing direction mask code to
be a little cleaner.

- Moved the main part of the homing cycle control and execution to
motion_control.c, where it fits better.

- Removed the STATE_INIT system state as it was redundant. Made the
system states into bitflags so multiple system states can be checked
via one if statement.

- Reorganized the power-up routine to work with the new system states.


----------------
Date: 2013-12-29
Author: Sonny Jeon
Subject: Merge branch 'dev' of https://github.com/grbl/grbl into dev

Conflicts:
	limits.c


----------------
Date: 2013-12-29
Author: Sonny Jeon
Subject: Merge branch 'dev' of https://github.com/grbl/grbl into dev

Conflicts:
	limits.c


----------------
Date: 2013-12-27
Author: Sonny Jeon
Subject: Merge pull request #312 from scottrcarlson/dev

Fixed homing_dir_mask functionality in the re-written homing_cycle.

----------------
Date: 2013-12-27
Author: Scott R Carlson
Subject: Hard Limits configured for active high.

Added the use of homing_dir_mask to homing_cycle


----------------
Date: 2013-12-10
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2013-12-10
Author: Sonny Jeon
Subject: Revamped homing cycle. Axis limits and max travel bug fixes. Build info. Refactored config.h.

- Revamped and improved homing cycle. Now tied directly into the main
planner and stepper code, which enables much faster homing seek rates.
Also dropped the compiled flash size by almost 1KB, meaning 1KB more
for other features.

- Refactored config.h. Removed obsolete defines and configuration
options. Moved lots of “advanced” options into the advanced area of the
file.

- Updated defaults.h with the new homing cycle. Also updated the
Sherline 5400 defaults and added the ShapeOko2 defaults per user
submissions.

- Fixed a bug where the individual axes limits on velocity and
acceleration were not working correctly. Caused by abs() returning a
int, rather than a float. Corrected with fabs(). Duh.

- Added build version/date to the Grbl welcome message to help indicate
which version a user is operating on.

- Max travel settings were not being defaulted into the settings EEPROM
correctly. Fixed.

- To stop a single axis during a multi-axes homing move, the stepper
algorithm now has a simple axis lock mask which inhibits the desired
axes from moving. Meaning, if one of the limit switches engages before
the other, we stop that one axes and keep moving the other.


----------------
Date: 2013-12-10
Author: Sonny Jeon
Subject: Merge pull request #301 from shapeoko/master

added shapeoko2 profile

----------------
Date: 2013-12-10
Author: Edward
Subject: added shapeoko2 profile

shapeoko 2 uses 2mm GT2 belting and 20tooth pulleys


----------------
Date: 2013-12-07
Author: Sonny Jeon
Subject: Deceleration to zero speed improvements. Update defaults.

- A minor issue with deceleration ramps when close to zero velocity.
Should be virtually unnoticeable for most CNC systems, but fixed in
this push and accurate to physics.

- Updated some of the junction deviation defaults. Because the new
stepper algorithm can easily maximize a CNC machine’s capabilities or
simply go much faster, this means the speed in which it enters
junctions has to be a little more constrained. Meaning that, we have to
slow a little bit down more so that we don’t exceed the acceleration
limits of the stepper motors.


----------------
Date: 2013-12-07
Author: Sonny Jeon
Subject: Pushed bug fixes. Updated readme.

- G18 plane select fix from XZ-plane to ZX-plane per right hand rule.

- Added volatile declaration for rx_buffer_tail in serial.c. No real
effect to operation as avr-gcc adds this upon compilation. Helps with
porting issues when using a different compiler.


----------------
Date: 2013-12-07
Author: Sonny Jeon
Subject: Pushed limits active high option. Updated defaults.h. Misc bug fixes. Cleaned up codebase.

- Pushed limit switch active high option (i.e. NC switches).

- Updated defaults.h to be in-line with the new settings.

- Refactored feed hold handling and step segment buffer to be more
generalized in effort to make adding feedrate overrides easier in the
future. Also made it a little more clean.

- Fixed G18 plane select issue. Now ZX-plane, rather than XZ-plane, per
right hand rule.

- Cleaned some of the system settings by more accurately renaming some
of the variables and removing old obsolete ones.

- Declared serial.c rx_buffer_tail to be volatile. No effect, since
avr-gcc automatically does this during compilation. Helps with porting
when using other compilers.

- Updated version number to v0.9b.

- Updates to README.md


----------------
Date: 2013-12-04
Author: Sonny Jeon
Subject: Reinstated feed holds into new stepper algorithm and planner. Rough draft, but working.

- Reinstated the feed hold feature with the new stepper algorithm and
new optimized planner. It works, but will be re-factored a bit soon to
clean up the code.

- At this point, feedrate overrides may need to be installed in the
v1.0 version of grbl, while this version will likely be pushed to the
edge branch soon and pushed to master after the bugs have been squashed.

- Measured the overall performance of the new planner and stepper
algorithm on an oscilloscope. The new planner is about 4x faster than
before, where it is completing a plan in around 1ms. The stepper
algorithm itself is minutely faster, as it is a little lighter. The
trade-off in the increased planner performance comes from the new step
segment buffer. However, even in the worse case scenario, the step
segment buffer generates a new segment with a typical 0.2 ms, and the
worse case is 1ms upon a new block or replanning the active block.
Added altogether, it’s argubly still twice as efficient as the old one.


----------------
Date: 2013-11-23
Author: Sonny Jeon
Subject: Merge pull request #289 from Travis-Snoozy/master

Add support for active-high limit switches

----------------
Date: 2013-11-22
Author: Travis Snoozy
Subject: Add support for active-high limit switches


----------------
Date: 2013-11-22
Author: Sonny Jeon
Subject: Yet another major stepper algorithm and planner overhaul.

- Overhauled the stepper algorithm and planner again. This time
concentrating on the decoupling of the stepper ISR completely. It is
now dumb, relying on the segment generator to provide the number of
steps to execute and how fast it needs to go. This freed up lots of
memory as well because it made a lot tracked variables obsolete.

- The segment generator now computes the velocity profile of the
executing planner block on the fly in floating point math, instead of
allowing the stepper algorithm to govern accelerations in the previous
code. What this accomplishes is the ability and framework to (somewhat)
easily install a different physics model for generating a velocity
profile, i.e. s-curves.

- Made some more planner enhancements and increased efficiency a bit.

- The changes also did not increase the compiled size of Grbl, but
decreased it slightly as well.

- Cleaned up a lot of the commenting.

- Still much to do, but this push works and still is missing feedholds
(coming next.)


----------------
Date: 2013-10-29
Author: Sonny Jeon
Subject: Another merge fix.


----------------
Date: 2013-10-29
Author: Sonny Jeon
Subject: Merge fixes.


----------------
Date: 2013-10-29
Author: Sonny Jeon
Subject: Merge branch 'dev_2' into dev

Conflicts:
	README.md
	gcode.c
	motion_control.c
	planner.c
	planner.h
	protocol.c
	report.c
	settings.c
	settings.h
	stepper.c
	stepper.h


----------------
Date: 2013-10-29
Author: Sonny Jeon
Subject: Merge branch 'dev_2' into dev

Conflicts:
README.md
gcode.c
motion_control.c
planner.c
planner.h
protocol.c
report.c
settings.c
settings.h
stepper.c
stepper.h


----------------
Date: 2013-10-29
Author: Sonny Jeon
Subject: Planner function call fix. More clean up.


----------------
Date: 2013-10-29
Author: Sonny Jeon
Subject: Updated comments. Changed stepper variable names to be more understandable. Added step locking note.

- Updated config comments and stepper code comments for the new changes.

- Changed stepper algorithm variable names to be more understandable in
what they actually do.

- Added a stepper lock note in default.h per user request.

- Started some code layout in handling feed holds and refactoring the
homing routine to use the main stepper algorithm instead of a seperate
version.


----------------
Date: 2013-10-24
Author: Sonny Jeon
Subject: Cleaned up stepper and planner code.

- Added some compile-time error checking. Will add more in future
pushes to ensure settings are correct and within parameters that won't
break anything.

- Pushed some master branch changes with MEGA pin settings.

- Cleaned up planner code and comments to clarify some of the new
changes. Still much to do here.

- Cleaned up the new stepper code. May need to abstract some of the
segment buffer more to fix the feed holds (and integrate homing into
the main stepper routine). With what's planned, this should make the
stepper algorithm easier to attach other types of processes to it,
where it is now tightly integrated with the planner buffer and nothing
else.


----------------
Date: 2013-10-21
Author: Sonny Jeon
Subject: Merge pull request #279 from EliteEng/master

Changed Stepper Pins

----------------
Date: 2013-10-18
Author: Rob Brown
Subject: Changed Stepper Pins

Changed Stepper Pins so the Step Port Invert Mask matches the UNO


----------------
Date: 2013-10-17
Author: Sonny Jeon
Subject: Merge pull request #278 from EliteEng/master

Update Pin Change Interrupts on Mega 2560

----------------
Date: 2013-10-17
Author: Rob Brown
Subject: Update Pin Change Interrupts so it works

PCIE1 - Interrupt 8 on the Mega is attached to USART0 RX so when any
serial communication was transmitted it was triggering the Reset
Interrupt


----------------
Date: 2013-10-14
Author: Sonny Jeon
Subject: Fine tuning of new stepper algorithm with protected planner. Adaptive step prediction for segment buffer.

- Cleaned up the new stepper algorithm code with more commenting and
better logic flow.

- The new segment buffer now predicts the number of steps each segment
should have to execute over about 8 milliseconds each (based on the
ACCELERATION_TICKS_PER_SECOND setting). So, for when the whole segment
buffer is full, the stepper algorithm has roughly 40 milliseconds of
steps queued before it needs to refilled by the main program.

- Readjusted the max supported step rate back to 30kHz from the lower
development 20kHz. Everything still works amazing great and the test
CNC machine still runs twice as fast with the new stepper algorithm and
planner.

- Upped the standard serial baudrate to 115200 baud, as it is clear
that the bottleneck is the serial interface. Will now support this, as
well as the old 9600 baud, in new firmware builds.


----------------
Date: 2013-10-12
Author: Sonny Jeon
Subject: New stepper subsystem bug fixes.

- New stepper algorithm with the new optimized planner seems to be
working nearly twice as fast as the previous algorithm.

- For one, the planner computation overhead is probably a fraction of
what it used to be with the worst case being about half still.

- Secondly, anytime the planner plans back to the first executing
block, it no longer overwrites the block conditions and allows it to
complete without lost steps. So no matter if the streams slows, the
protected planner should keep the steppers moving without risk of lost
steps (although this still needs to be tested thoroughly and may
audibly sound weird when this happens.)

- It now seems that the bottleneck is the serial baudrate (which is
good!)


----------------
Date: 2013-10-09
Author: Sonny Jeon
Subject: Protected buffer works! Vast improvements to planner efficiency.  Many things still broken with overhaul.

Development push. Lots still broken.

- Protected planner concept works! This is a critical precursor to
enabling feedrate overrides in allowing the planner buffer and the
stepper execution operate atomically. This is done through a
intermediary segment buffer.

- Still lots of work to be done, as this was a complete overhaul of the
planner and stepper subsystems. The code can be cleaned up quite a bit,
re-enabling some of the broken features like feed holds, and finishing
up some of the concepts

- Pushed some of the fixes from the master and edge branch to here, as
this will likely replace the edge branch when done.


----------------
Date: 2013-08-25
Author: Sonny Jeon
Subject: Merge pull request #263 from 0xPIT/master

remove mcu argument for avr-size in makefile as it is not present in GNU...

----------------
Date: 2013-08-25
Author: 0xPIT
Subject: remove mcu argument for avr-size in makefile as it is not present in GNU Binutils 2.22


----------------
Date: 2013-08-20
Author: Sonny Jeon
Subject: Pin map definition cleanup.


----------------
Date: 2013-08-19
Author: Sonny Jeon
Subject: Processor-independent pin mapping feature.

- Cleaned up and organized pin mapping concept by @elmom.

- pin_map.h allows for user-supplied pin mapping and port vector
definitions in a centralized file. With more processor types, more
definitions could be added.


----------------
Date: 2013-08-19
Author: Sonny Jeon
Subject: Merge pull request #260 from elmom/master

Thanks for the contribution! Looks good. Will update some of the semantics shortly, but the idea is solid.

----------------
Date: 2013-08-19
Author: Sonny Jeon
Subject: Push old dev_2 draft to work on other things.

- **NON-FUNCTIONAL**
- Contains an old draft of separating the stepper driver direct access
to the planner buffer. This is designed to keep the stepper and planner
modules independent and prevent overwriting or other complications. In
this way, feedrate override should be able to be installed as well.
- A number of planner optimizations are installed too.
- Not sure where the bugs are. Either in the new planner optimizations,
new stepper module updates, or in both. Or it just could be that the
Arduino AVR is choking with the new things it has to do.


----------------
Date: 2013-08-19
Author: Sonny Jeon
Subject: Merge pull request #229 from 0xPIT/patch-1

fix command line parameter for avr-size

----------------
Date: 2013-07-21
Author: Elmo Mäntynen
Subject: Refactor config.h to allow defaults for chips/boards with different pin mappings


----------------
Date: 2013-07-21
Author: Elmo Mäntynen
Subject: Added pin mapping list to docs, useful for porting


----------------
Date: 2013-07-21
Author: Elmo Mäntynen
Subject: Make serial work with most chips by default


----------------
Date: 2013-05-16
Author: 0xPIT
Subject: fix command line parameter for avr-size

----------------
Date: 2013-04-05
Author: Sonny Jeon
Subject: Updated readme


----------------
Date: 2013-04-05
Author: Sonny Jeon
Subject: Increased g-code parser line buffer. Added line overflow feedback.

- Increased g-code parser line buffer from 50 to 70 characters. Should
fix most all issues with long arc statements, provided that they are 8
digits(float) long only.

- Added a line buffer overflow feedback error to let the user know when
it encounters this problem. Resets the line whenever this occurs.
(Thanks @BHSPitMonkey!)


----------------
Date: 2013-04-05
Author: Sonny Jeon
Subject: Updates to edge/dev. Line buffer increased/planner buffer decreased. Line overflow feedback.

- Increased g-code parser line buffer to 70 characters (from 50) to
prevent some long arc commands from getting truncated.

- Decreased planner buffer from 18 to 17 blocks to free up memory for
line buffer.

- Added a line buffer overflow feedback error (Thanks @BHSPitMonkey!)


----------------
Date: 2013-03-28
Author: Sonny Jeon
Subject: Minor updates to code and commenting.


----------------
Date: 2013-03-22
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2013-03-21
Author: Sonny Jeon
Subject: 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.

-


----------------
Date: 2013-03-19
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2013-03-19
Author: Sonny Jeon
Subject: G-code updates for G10 L2 and L20

- Updated g-codes G10 L2 and G10 L20 to the new descriptions on
linuxcnc.org


----------------
Date: 2013-03-19
Author: Sonny Jeon
Subject: G-code updates for G10 L2 and L20.

- LinuxCNC's g-code definitions changed for G10. Updated to their
descriptions.


----------------
Date: 2013-03-13
Author: Bertus Kruger
Subject: Update planner.c

Removed inline from all functions. 

If this is really needed is there another way that we can get 
around using it? (The Arduino IDE does not recognize it) 

----------------
Date: 2013-03-13
Author: Bertus Kruger
Subject: Update nuts_bolts.c

Removed __floatunsisf and used normal casting on line 81. 
This makes it compatible with the Arduino IDE.

----------------
Date: 2013-03-12
Author: Sonny Jeon
Subject: Pushed minor changes. Thanks @Protoneer!


----------------
Date: 2013-03-12
Author: Sonny Jeon
Subject: Merge pull request #200 from Protoneer/master

Fixed small bug.

----------------
Date: 2013-03-13
Author: Bertus Kruger
Subject: Update gcode.c

Removed the home_select variable.

----------------
Date: 2013-03-13
Author: Bertus Kruger
Subject: Update eeprom.h

Fixed the function signature.

----------------
Date: 2013-03-13
Author: Bertus Kruger
Subject: Update eeprom.c

Changed back

----------------
Date: 2013-03-12
Author: Bertus Kruger
Subject: Update gcode.c

home_select defined out of scope. Moved it outside the switch 
so the rest of the switch can see it properly. 

----------------
Date: 2013-03-12
Author: Bertus Kruger
Subject: Update eeprom.c

Function eeprom_put_char's parameters did not align with the .h file.

----------------
Date: 2013-03-01
Author: Sonny Jeon
Subject: Bug fix to-do note on soft limit checks. Not yet completed.


----------------
Date: 2013-03-01
Author: Sonny Jeon
Subject: Minor changes and added notes to soft limits routines.

- Changed up mc_line to accept an array rather than individual x,y,z
coordinates. Makes some of the position data handling more effective,
especially for a 4th-axis later on.

- Changed up some soft limits variable names.


----------------
Date: 2013-02-26
Author: Sonny Jeon
Subject: Merge pull request #193 from bungao/soft_limts

integrating soft limits

----------------
Date: 2013-02-26
Author: Jens Geisler
Subject: bugfix: uninitiallized curr_block->new_entry_speed_sqr lead to step loss
in some cases

----------------
Date: 2013-02-26
Author: bungao
Subject: integrating soft limits


----------------
Date: 2013-02-22
Author: Sonny Jeon
Subject: Added some prelimary notes to new changes.


----------------
Date: 2013-02-22
Author: Sonny Jeon
Subject: Push additional updates from @jgeisler0303


----------------
Date: 2013-02-22
Author: Jens Geisler
Subject: changed atomic access for updating the acceleration profile
the stepper interrupt is only halted when necessary and for the shortest
time possible (8% cycle time)

----------------
Date: 2013-02-20
Author: Sonny Jeon
Subject: Merge pull request #188 from jgeisler0303/new_planner

New planner commits merge into dev branch.

----------------
Date: 2013-02-20
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2013-02-20
Author: Jens Geisler
Subject: added counter for planner steps

----------------
Date: 2013-02-20
Author: Jens Geisler
Subject: implemented a mixture of Sonny's MATLAB and my previous grbl planner
ontop of the edge planner
examples run byte for byte identical old and new version

----------------
Date: 2013-01-18
Author: Sonny Jeon
Subject: Merge pull request #169 from silasb/fix-execute-bit-on-files

Removing executable bit on the files

----------------
Date: 2013-01-18
Author: Sonny Jeon
Subject: Merge bug fixes from recent v0.8c push. Added readme for Grbl Sim.


----------------
Date: 2013-01-18
Author: Sonny Jeon
Subject: Merge pull request #167 from tmpvar/simulator-mac

Fix sim makefile so it works on mac

----------------
Date: 2013-01-18
Author: Elijah Insua
Subject: Fix sim makefile so it works on mac

These changes include a path separator fix and the removal of --gc-sections which causes ld failures, and is not needed on a pc.

This patch also changes how a compiler is selected.  The makefile will now select the system compiler , which should work fine
under mingw and linux.


----------------
Date: 2013-01-17
Author: Silas Baronda
Subject: Removing executable bit on the files


----------------
Date: 2013-01-17
Author: Sonny Jeon
Subject: Merge pull request #112 from jgeisler0303/simulator

Grbl Simulator. Oh yeah. 

----------------
Date: 2013-01-17
Author: Jens Geisler
Subject: relaunch ontop of latest grbl edge
code very messy but tested

----------------
Date: 2013-01-09
Author: Sonny Jeon
Subject: Merge pull request #160 from daapp/edge

Replace some constants with N_AXIS.

----------------
Date: 2013-01-10
Author: Alexander Danilov
Subject: Replace some constants with N_AXIS.


----------------
Date: 2013-01-06
Author: Sonny Jeon
Subject: Fixed bug with homing and polling at the same time. Updated readme.


----------------
Date: 2013-01-06
Author: Sonny Jeon
Subject: Minor changes.

- Changed some names up and removed a plan_reset() function that is
never used.


----------------
Date: 2012-12-21
Author: Sonny Jeon
Subject: Readme link to edge build 2012-12-21


----------------
Date: 2012-12-21
Author: Sonny Jeon
Subject: Updated README. Max step rate back at 30kHz. Acceleration minor bug fix.

- Returned the max step rate to 30kHz. The new arc algorithm works uses
so much less CPU overhead, because the segments are longer, that the
planner has no problem computing through them.

- Fixed an issue with the acceleration independence scaling. Should now
work with accelerations above 400mm/sec^2 or so.

- Updated README


----------------
Date: 2012-12-19
Author: Sonny Jeon
Subject: Arc mm_per_segment removed, now in terms of tolerance. Stepper ramp counter variable type corrected.

- Arc mm_per_segment parameter was removed and replaced with an
arc_tolerance parameter, which scales all arc segments automatically to
radius, such that the line segment error doesn't exceed the tolerance.
Significantly improves arc performance through larger radius arc,
because the segments are much longer and the planner buffer has more to
work with.

- Moved n_arc correction from the settings to config.h. Mathematically
this doesn't need to be a setting anymore, as the default config value
will work for all known CNC applications. The error does not accumulate
as much anymore, since the small angle approximation used by the arc
generation has been updated to a third-order approximation and how the
line segment length scale with radius and tolerance now. Left in
config.h for extraneous circumstances.

- Corrected the st.ramp_count variable (acceleration tick counter) to a
8-bit vs. 32-bit variable. Should make the stepper algorithm just a
touch faster overall.


----------------
Date: 2012-12-16
Author: Sonny Jeon
Subject: Slow trailing steps fix. Added more defaults.

- Fixed an issue (hopefully) with slow trailing steps after a
triangular velocity profile move. Sets the trapezoid tick cycle counter
to the correct value for an accurate reproduction of the deceleration
curve. Keeps it from arriving too early to the target position, which
causes the slow trailing steps.

- Added Zen Toolworks 7x7 to default settings.

- Updated readme with new edge build.


----------------
Date: 2012-12-16
Author: Sonny Jeon
Subject: Max velocity axes independence installed. Fixed intermittent slow trailing steps. Timer0 disable fix.

- Maximum velocity for each axis is now configurable in settings. All
rapids/seek move at these maximums. All feed rates(including rapids)
may be limited and scaled down so that no axis does not exceed their
limits.

- Moved around auto-cycle start. May change later, but mainly to ensure
the planner buffer is completely full before cycle starting a streaming
program. Otherwise it should auto-start when there is a break in the
serial stream.

- Reverted old block->max_entry_speed_sqr calculations. Feedrate
overrides not close to ready at all.

- Fixed intermittent slow trailing steps for some triangle velocity
profile moves. The acceleration tick counter updating was corrected to
be exact for that particular transition. Should be ok for normal
trapezoidal profiles.

- Fixed the Timer0 disable after a step pulse falling edge. Thanks
@blinkenlight!


----------------
Date: 2012-12-14
Author: Sonny Jeon
Subject: Acceleration independence installed. Initial re-work of planner for feedrate overrides.

NOTE: This push is a work-in-progress and there are known bugs that
need to be fixed, like homing acceleration being incompatible. Released
for testing. Settings will definitely be overwritten, as new settings
were needed.

- Acceleration independence installed in planner. Each axis can now
have different accelerations and Grbl will maximize the accelerations
depending on the direction its moving. Very useful for users like on
the ShapeOko with vastly different Z-axis properties.

- More planner optimizations and re-factoring. Slightly improved some
of the older calculations, but new acceleration calculations offset
these improvements. Overall no change in processing speed.

- Removed planner nominal length checks. It was arguable whether or not
this improved planner efficiency, especially in the worst case scenario
of arcs.

- Updated readme and changed to markdown format.


----------------
Date: 2012-12-12
Author: Sonny Jeon
Subject: Update README.md

----------------
Date: 2012-12-12
Author: Sonny Jeon
Subject: Changed README to markdown


----------------
Date: 2012-12-12
Author: Sonny Jeon
Subject: Added download links to README.


----------------
Date: 2012-12-12
Author: Sonny Jeon
Subject: Moved compiled builds to different repo.


----------------
Date: 2012-12-11
Author: Sonny Jeon
Subject: Added builds folder.

Because the Downloads section has been removed, added a builds folder
for users to download pre-compiled firmware without needing to compile
it themselves.


----------------
Date: 2012-12-11
Author: Sonny Jeon
Subject: Added builds folder.

In light of the downloads section in Github being removed, added a
builds folder for all of the .hex files. Hopefully these won't be
removed either.


----------------
Date: 2012-12-11
Author: Sonny Jeon
Subject: Planner optimizations.

- Improved planner execution speed by 5% or more. Re-factored most of
the calculations in terms of the square of velocity. This removed a lot
of sqrt() calculations for every planner_recalculate.


----------------
Date: 2012-12-10
Author: Sonny Jeon
Subject: (Another) Planner bug fix.

- Oops again. Thought the new planner changes made things much better,
but there was a bug. Improvements we on the order of 20% execution time
reduction, rather than half. The increase to 30kHz Ranade timer
frequency also increased the overall overhead, so the total planner
change? Zero. But, it's still better.


----------------
Date: 2012-12-10
Author: Sonny Jeon
Subject: Planner bug fix.

- Oops! Misplace an if-then statement. Should work as advertised now.
(Hopefully)


----------------
Date: 2012-12-10
Author: Sonny Jeon
Subject: Planner execution time halved and bug fixes. Increased step rate limit to 30kHz.

- Planner execute speed has been more than halved from 4ms to 1.9ms
when computing a plan for a single line segment during arc generation.
This means that Grbl can now run through an arc (or complex curve)
twice as fast as before without starving the buffer. For 0.1mm arc
segments, this means about the theoretical feed rate limit is about
3000mm/min for arcs now.

- Increased the Ranade timer frequency to 30kHz, as there doesn't seem
to be any problems with increasing the frequency. This means that the
maximum step frequency is now back at 30kHz.

- Added Zen Toolworks 7x7 defaults.


----------------
Date: 2012-12-08
Author: Sonny Jeon
Subject: New stepper algorithm. Optimized planner.

- Brand-new stepper algorithm. Based on the Pramod Ranade inverse time
algorithm, but modified to ensure step events are exact. Currently
limited to about 15kHz step rates, much more to be done to enable 30kHz
again.

- Removed Timer1. Stepper algorithm now uses Timer0 and Timer2.

- Much improved step generation during accelerations. Smoother. Allows
much higher accelerations (and speeds) than before on the same machine.

- Cleaner algorithm that is more easily portable to other CPU types.

- Streamlined planner calculations. Removed accelerate_until and
final_rate variables from block buffer since the new stepper algorithm
is that much more accurate.

- Improved planner efficiency by about 15-20% during worst case
scenarios (arcs).

- New config.h options to tune new stepper algorithm.