/*
gcode.c - rs274/ngc parser.
Part of Grbl
Copyright (c) 2009-2011 Simen Svale Skogsrud
Copyright (c) 2011-2012 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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Grbl is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Grbl. If not, see .
*/
/* This code is inspired by the Arduino GCode Interpreter by Mike Ellery and the NIST RS274/NGC Interpreter
by Kramer, Proctor and Messina. */
#include "gcode.h"
#include
#include "nuts_bolts.h"
#include
#include "settings.h"
#include "motion_control.h"
#include "spindle_control.h"
#include "coolant_control.h"
#include "errno.h"
#include "protocol.h"
#include "report.h"
// Declare gc extern struct
parser_state_t gc;
#define FAIL(status) gc.status_code = status;
static int next_statement(char *letter, float *float_ptr, char *line, uint8_t *char_counter);
static void select_plane(uint8_t axis_0, uint8_t axis_1, uint8_t axis_2)
{
gc.plane_axis_0 = axis_0;
gc.plane_axis_1 = axis_1;
gc.plane_axis_2 = axis_2;
}
void gc_init()
{
memset(&gc, 0, sizeof(gc));
gc.feed_rate = settings.default_feed_rate; // Should be zero at initialization.
// gc.seek_rate = settings.default_seek_rate;
select_plane(X_AXIS, Y_AXIS, Z_AXIS);
gc.absolute_mode = true;
// Load default G54 coordinate system.
if (!(settings_read_coord_data(gc.coord_select,gc.coord_system))) {
report_status_message(STATUS_SETTING_READ_FAIL);
}
}
// Sets g-code parser position in mm. Input in steps. Called by the system abort and hard
// limit pull-off routines.
void gc_set_current_position(int32_t x, int32_t y, int32_t z)
{
gc.position[X_AXIS] = x/settings.steps_per_mm[X_AXIS];
gc.position[Y_AXIS] = y/settings.steps_per_mm[Y_AXIS];
gc.position[Z_AXIS] = z/settings.steps_per_mm[Z_AXIS];
}
static float to_millimeters(float value)
{
return(gc.inches_mode ? (value * MM_PER_INCH) : value);
}
// Executes one line of 0-terminated G-Code. The line is assumed to contain only uppercase
// characters and signed floating point values (no whitespace). Comments and block delete
// characters have been removed. All units and positions are converted and exported to grbl's
// internal functions in terms of (mm, mm/min) and absolute machine coordinates, respectively.
uint8_t gc_execute_line(char *line)
{
// If in alarm state, don't process. Immediately return with error.
// NOTE: Might not be right place for this, but also prevents $N storing during alarm.
if (sys.state == STATE_ALARM) { return(STATUS_ALARM_LOCK); }
uint8_t char_counter = 0;
char letter;
float value;
int int_value;
uint16_t modal_group_words = 0; // Bitflag variable to track and check modal group words in block
uint8_t axis_words = 0; // Bitflag to track which XYZ(ABC) parameters exist in block
float inverse_feed_rate = -1; // negative inverse_feed_rate means no inverse_feed_rate specified
uint8_t absolute_override = false; // true(1) = absolute motion for this block only {G53}
uint8_t non_modal_action = NON_MODAL_NONE; // Tracks the actions of modal group 0 (non-modal)
float target[3], offset[3];
clear_vector(target); // XYZ(ABC) axes parameters.
clear_vector(offset); // IJK Arc offsets are incremental. Value of zero indicates no change.
gc.status_code = STATUS_OK;
/* Pass 1: Commands and set all modes. Check for modal group violations.
NOTE: Modal group numbers are defined in Table 4 of NIST RS274-NGC v3, pg.20 */
uint8_t group_number = MODAL_GROUP_NONE;
while(next_statement(&letter, &value, line, &char_counter)) {
int_value = trunc(value);
switch(letter) {
case 'G':
// Set modal group values
switch(int_value) {
case 4: case 10: case 28: case 30: case 53: case 92: group_number = MODAL_GROUP_0; break;
case 0: case 1: case 2: case 3: case 80: group_number = MODAL_GROUP_1; break;
case 17: case 18: case 19: group_number = MODAL_GROUP_2; break;
case 90: case 91: group_number = MODAL_GROUP_3; break;
case 93: case 94: group_number = MODAL_GROUP_5; break;
case 20: case 21: group_number = MODAL_GROUP_6; break;
case 54: case 55: case 56: case 57: case 58: case 59: group_number = MODAL_GROUP_12; break;
}
// Set 'G' commands
switch(int_value) {
case 0: gc.motion_mode = MOTION_MODE_SEEK; break;
case 1: gc.motion_mode = MOTION_MODE_LINEAR; break;
case 2: gc.motion_mode = MOTION_MODE_CW_ARC; break;
case 3: gc.motion_mode = MOTION_MODE_CCW_ARC; break;
case 4: non_modal_action = NON_MODAL_DWELL; break;
case 10: non_modal_action = NON_MODAL_SET_COORDINATE_DATA; break;
case 17: select_plane(X_AXIS, Y_AXIS, Z_AXIS); break;
case 18: select_plane(X_AXIS, Z_AXIS, Y_AXIS); break;
case 19: select_plane(Y_AXIS, Z_AXIS, X_AXIS); break;
case 20: gc.inches_mode = true; break;
case 21: gc.inches_mode = false; break;
case 28: case 30:
int_value = trunc(10*value); // Multiply by 10 to pick up Gxx.1
switch(int_value) {
case 280: non_modal_action = NON_MODAL_GO_HOME_0; break;
case 281: non_modal_action = NON_MODAL_SET_HOME_0; break;
case 300: non_modal_action = NON_MODAL_GO_HOME_1; break;
case 301: non_modal_action = NON_MODAL_SET_HOME_1; break;
default: FAIL(STATUS_UNSUPPORTED_STATEMENT);
}
break;
case 53: absolute_override = true; break;
case 54: case 55: case 56: case 57: case 58: case 59:
gc.coord_select = int_value-54;
break;
case 80: gc.motion_mode = MOTION_MODE_CANCEL; break;
case 90: gc.absolute_mode = true; break;
case 91: gc.absolute_mode = false; break;
case 92:
int_value = trunc(10*value); // Multiply by 10 to pick up G92.1
switch(int_value) {
case 920: non_modal_action = NON_MODAL_SET_COORDINATE_OFFSET; break;
case 921: non_modal_action = NON_MODAL_RESET_COORDINATE_OFFSET; break;
default: FAIL(STATUS_UNSUPPORTED_STATEMENT);
}
break;
case 93: gc.inverse_feed_rate_mode = true; break;
case 94: gc.inverse_feed_rate_mode = false; break;
default: FAIL(STATUS_UNSUPPORTED_STATEMENT);
}
break;
case 'M':
// Set modal group values
switch(int_value) {
case 0: case 1: case 2: case 30: group_number = MODAL_GROUP_4; break;
case 3: case 4: case 5: group_number = MODAL_GROUP_7; break;
}
// Set 'M' commands
switch(int_value) {
case 0: gc.program_flow = PROGRAM_FLOW_PAUSED; break; // Program pause
case 1: break; // Optional stop not supported. Ignore.
case 2: case 30: gc.program_flow = PROGRAM_FLOW_COMPLETED; break; // Program end and reset
case 3: gc.spindle_direction = 1; break;
case 4: gc.spindle_direction = -1; break;
case 5: gc.spindle_direction = 0; break;
#ifdef ENABLE_M7
case 7: gc.coolant_mode = COOLANT_MIST_ENABLE; break;
#endif
case 8: gc.coolant_mode = COOLANT_FLOOD_ENABLE; break;
case 9: gc.coolant_mode = COOLANT_DISABLE; break;
default: FAIL(STATUS_UNSUPPORTED_STATEMENT);
}
break;
}
// Check for modal group multiple command violations in the current block
if (group_number) {
if ( bit_istrue(modal_group_words,bit(group_number)) ) {
FAIL(STATUS_MODAL_GROUP_VIOLATION);
} else {
bit_true(modal_group_words,bit(group_number));
}
group_number = MODAL_GROUP_NONE; // Reset for next command.
}
}
// If there were any errors parsing this line, we will return right away with the bad news
if (gc.status_code) { return(gc.status_code); }
/* Pass 2: Parameters. All units converted according to current block commands. Position
parameters are converted and flagged to indicate a change. These can have multiple connotations
for different commands. Each will be converted to their proper value upon execution. */
float p = 0, r = 0;
uint8_t l = 0;
char_counter = 0;
while(next_statement(&letter, &value, line, &char_counter)) {
switch(letter) {
case 'G': case 'M': case 'N': break; // Ignore command statements and line numbers
case 'F':
if (value <= 0) { FAIL(STATUS_INVALID_STATEMENT); } // Must be greater than zero
if (gc.inverse_feed_rate_mode) {
inverse_feed_rate = to_millimeters(value); // seconds per motion for this motion only
} else {
gc.feed_rate = to_millimeters(value); // millimeters per minute
}
break;
case 'I': case 'J': case 'K': offset[letter-'I'] = to_millimeters(value); break;
case 'L': l = trunc(value); break;
case 'P': p = value; break;
case 'R': r = to_millimeters(value); break;
case 'S':
if (value < 0) { FAIL(STATUS_INVALID_STATEMENT); } // Cannot be negative
// TBD: Spindle speed not supported due to PWM issues, but may come back once resolved.
// gc.spindle_speed = value;
break;
case 'T':
if (value < 0) { FAIL(STATUS_INVALID_STATEMENT); } // Cannot be negative
gc.tool = trunc(value);
break;
case 'X': target[X_AXIS] = to_millimeters(value); bit_true(axis_words,bit(X_AXIS)); break;
case 'Y': target[Y_AXIS] = to_millimeters(value); bit_true(axis_words,bit(Y_AXIS)); break;
case 'Z': target[Z_AXIS] = to_millimeters(value); bit_true(axis_words,bit(Z_AXIS)); break;
default: FAIL(STATUS_UNSUPPORTED_STATEMENT);
}
}
// If there were any errors parsing this line, we will return right away with the bad news
if (gc.status_code) { return(gc.status_code); }
/* Execute Commands: Perform by order of execution defined in NIST RS274-NGC.v3, Table 8, pg.41.
NOTE: Independent non-motion/settings parameters are set out of this order for code efficiency
and simplicity purposes, but this should not affect proper g-code execution. */
// ([F]: Set feed and seek rates.)
// TODO: Seek rates can change depending on the direction and maximum speeds of each axes. When
// max axis speed is installed, the calculation can be performed here, or maybe in the planner.
if (sys.state != STATE_CHECK_MODE) {
// ([M6]: Tool change should be executed here.)
// [M3,M4,M5]: Update spindle state
spindle_run(gc.spindle_direction);
// [*M7,M8,M9]: Update coolant state
coolant_run(gc.coolant_mode);
}
// [G54,G55,...,G59]: Coordinate system selection
if ( bit_istrue(modal_group_words,bit(MODAL_GROUP_12)) ) { // Check if called in block
float coord_data[N_AXIS];
if (!(settings_read_coord_data(gc.coord_select,coord_data))) { return(STATUS_SETTING_READ_FAIL); }
memcpy(gc.coord_system,coord_data,sizeof(coord_data));
}
// [G4,G10,G28,G30,G92,G92.1]: Perform dwell, set coordinate system data, homing, or set axis offsets.
// NOTE: These commands are in the same modal group, hence are mutually exclusive. G53 is in this
// modal group and do not effect these actions.
switch (non_modal_action) {
case NON_MODAL_DWELL:
if (p < 0) { // Time cannot be negative.
FAIL(STATUS_INVALID_STATEMENT);
} else {
// Ignore dwell in check gcode modes
if (sys.state != STATE_CHECK_MODE) { mc_dwell(p); }
}
break;
case NON_MODAL_SET_COORDINATE_DATA:
int_value = trunc(p); // Convert p value to int.
if ((l != 2 && l != 20) || (int_value < 1 || int_value > N_COORDINATE_SYSTEM)) { // L2 and L20. P1=G54, P2=G55, ...
FAIL(STATUS_UNSUPPORTED_STATEMENT);
} else if (!axis_words && l==2) { // No axis words.
FAIL(STATUS_INVALID_STATEMENT);
} else {
int_value--; // Adjust P index to EEPROM coordinate data indexing.
if (l == 20) {
settings_write_coord_data(int_value,gc.position);
// Update system coordinate system if currently active.
if (gc.coord_select == int_value) { memcpy(gc.coord_system,gc.position,sizeof(gc.position)); }
} else {
float coord_data[N_AXIS];
if (!settings_read_coord_data(int_value,coord_data)) { return(STATUS_SETTING_READ_FAIL); }
// Update axes defined only in block. Always in machine coordinates. Can change non-active system.
uint8_t i;
for (i=0; i C -----------------+--------------- T <- [x,y]
| <------ d/2 ---->|
C - Current position
T - Target position
O - center of circle that pass through both C and T
d - distance from C to T
r - designated radius
h - distance from center of CT to O
Expanding the equations:
d -> sqrt(x^2 + y^2)
h -> sqrt(4 * r^2 - x^2 - y^2)/2
i -> (x - (y * sqrt(4 * r^2 - x^2 - y^2)) / sqrt(x^2 + y^2)) / 2
j -> (y + (x * sqrt(4 * r^2 - x^2 - y^2)) / sqrt(x^2 + y^2)) / 2
Which can be written:
i -> (x - (y * sqrt(4 * r^2 - x^2 - y^2))/sqrt(x^2 + y^2))/2
j -> (y + (x * sqrt(4 * r^2 - x^2 - y^2))/sqrt(x^2 + y^2))/2
Which we for size and speed reasons optimize to:
h_x2_div_d = sqrt(4 * r^2 - x^2 - y^2)/sqrt(x^2 + y^2)
i = (x - (y * h_x2_div_d))/2
j = (y + (x * h_x2_div_d))/2
*/
// Calculate the change in position along each selected axis
float x = target[gc.plane_axis_0]-gc.position[gc.plane_axis_0];
float y = target[gc.plane_axis_1]-gc.position[gc.plane_axis_1];
clear_vector(offset);
// First, use h_x2_div_d to compute 4*h^2 to check if it is negative or r is smaller
// than d. If so, the sqrt of a negative number is complex and error out.
float h_x2_div_d = 4 * r*r - x*x - y*y;
if (h_x2_div_d < 0) { FAIL(STATUS_ARC_RADIUS_ERROR); return(gc.status_code); }
// Finish computing h_x2_div_d.
h_x2_div_d = -sqrt(h_x2_div_d)/hypot(x,y); // == -(h * 2 / d)
// Invert the sign of h_x2_div_d if the circle is counter clockwise (see sketch below)
if (gc.motion_mode == MOTION_MODE_CCW_ARC) { h_x2_div_d = -h_x2_div_d; }
/* The counter clockwise circle lies to the left of the target direction. When offset is positive,
the left hand circle will be generated - when it is negative the right hand circle is generated.
T <-- Target position
^
Clockwise circles with this center | Clockwise circles with this center will have
will have > 180 deg of angular travel | < 180 deg of angular travel, which is a good thing!
\ | /
center of arc when h_x2_div_d is positive -> x <----- | -----> x <- center of arc when h_x2_div_d is negative
|
|
C <-- Current position */
// Negative R is g-code-alese for "I want a circle with more than 180 degrees of travel" (go figure!),
// even though it is advised against ever generating such circles in a single line of g-code. By
// inverting the sign of h_x2_div_d the center of the circles is placed on the opposite side of the line of
// travel and thus we get the unadvisably long arcs as prescribed.
if (r < 0) {
h_x2_div_d = -h_x2_div_d;
r = -r; // Finished with r. Set to positive for mc_arc
}
// Complete the operation by calculating the actual center of the arc
offset[gc.plane_axis_0] = 0.5*(x-(y*h_x2_div_d));
offset[gc.plane_axis_1] = 0.5*(y+(x*h_x2_div_d));
} else { // Arc Center Format Offset Mode
r = hypot(offset[gc.plane_axis_0], offset[gc.plane_axis_1]); // Compute arc radius for mc_arc
}
// Set clockwise/counter-clockwise sign for mc_arc computations
uint8_t isclockwise = false;
if (gc.motion_mode == MOTION_MODE_CW_ARC) { isclockwise = true; }
// Trace the arc
mc_arc(gc.position, target, offset, gc.plane_axis_0, gc.plane_axis_1, gc.plane_axis_2,
(gc.inverse_feed_rate_mode) ? inverse_feed_rate : gc.feed_rate, gc.inverse_feed_rate_mode,
r, isclockwise);
}
break;
}
// Report any errors.
if (gc.status_code) { return(gc.status_code); }
// As far as the parser is concerned, the position is now == target. In reality the
// motion control system might still be processing the action and the real tool position
// in any intermediate location.
memcpy(gc.position, target, sizeof(target)); // gc.position[] = target[];
}
// M0,M1,M2,M30: Perform non-running program flow actions. During a program pause, the buffer may
// refill and can only be resumed by the cycle start run-time command.
if (gc.program_flow) {
plan_synchronize(); // Finish all remaining buffered motions. Program paused when complete.
sys.auto_start = false; // Disable auto cycle start. Forces pause until cycle start issued.
// If complete, reset to reload defaults (G92.2,G54,G17,G90,G94,M48,G40,M5,M9). Otherwise,
// re-enable program flow after pause complete, where cycle start will resume the program.
if (gc.program_flow == PROGRAM_FLOW_COMPLETED) { mc_reset(); }
else { gc.program_flow = PROGRAM_FLOW_RUNNING; }
}
return(gc.status_code);
}
// Parses the next statement and leaves the counter on the first character following
// the statement. Returns 1 if there was a statements, 0 if end of string was reached
// or there was an error (check state.status_code).
static int next_statement(char *letter, float *float_ptr, char *line, uint8_t *char_counter)
{
if (line[*char_counter] == 0) {
return(0); // No more statements
}
*letter = line[*char_counter];
if((*letter < 'A') || (*letter > 'Z')) {
FAIL(STATUS_EXPECTED_COMMAND_LETTER);
return(0);
}
(*char_counter)++;
if (!read_float(line, char_counter, float_ptr)) {
FAIL(STATUS_BAD_NUMBER_FORMAT);
return(0);
};
return(1);
}
/*
Not supported:
- Canned cycles
- Tool radius compensation
- A,B,C-axes
- Evaluation of expressions
- Variables
- Probing
- Override control (TBD)
- Tool changes
- Switches
(*) Indicates optional parameter, enabled through config.h and re-compile
group 0 = {G92.2, G92.3} (Non modal: Cancel and re-enable G92 offsets)
group 1 = {G38.2, G81 - G89} (Motion modes: straight probe, canned cycles)
group 4 = {M1} (Optional stop, ignored)
group 6 = {M6} (Tool change)
group 8 = {*M7} enable mist coolant
group 9 = {M48, M49} enable/disable feed and speed override switches
group 13 = {G61, G61.1, G64} path control mode
*/