// Directs and executes one line of formatted input from protocol_process. While mostly
// incoming streaming g-code blocks, this also directs and executes Grbl internal commands,
// such as settings, initiating the homing cycle, and toggling switch states.
static void protocol_execute_line(char *line)
{
protocol_execute_realtime(); // Runtime command check point.
if (sys.abort) { return; } // Bail to calling function upon system abort
#ifdef REPORT_ECHO_LINE_RECEIVED
report_echo_line_received(line);
#endif
if (line[0] == 0) {
// Empty or comment line. Send status message for syncing purposes.
report_status_message(STATUS_OK);
} else if (line[0] == '$') {
// Grbl '$' system command
report_status_message(system_execute_line(line));
} else if (sys.state == STATE_ALARM) {
// Everything else is gcode. Block if in alarm mode.
report_status_message(STATUS_ALARM_LOCK);
} else {
// Parse and execute g-code block!
report_status_message(gc_execute_line(line));
}
}
// Block until all buffered steps are executed or in a cycle state. Works with feed hold
// during a synchronize call, if it should happen. Also, waits for clean cycle end.
void protocol_buffer_synchronize()
{
// If system is queued, ensure cycle resumes if the auto start flag is present.
protocol_auto_cycle_start();
do {
protocol_execute_realtime(); // Check and execute run-time commands
if (sys.abort) { return; } // Check for system abort
} while (plan_get_current_block() || (sys.state == STATE_CYCLE));
}
// Performs a soft limit check. Called from mc_line() only. Assumes the machine has been homed,
// the workspace volume is in all negative space, and the system is in normal operation.
void limits_soft_check(float *target)
{
uint8_t idx;
uint8_t soft_limit_error = false;
for (idx=0; idx<N_AXIS; idx++) {
#ifdef HOMING_FORCE_SET_ORIGIN
// When homing forced set origin is enabled, soft limits checks need to account for directionality.
// NOTE: max_travel is stored as negative
if (bit_istrue(settings.homing_dir_mask,bit(idx))) {
if (target[idx] < 0 || target[idx] > -settings.max_travel[idx]) { soft_limit_error = true; }
} else {
if (target[idx] > 0 || target[idx] < settings.max_travel[idx]) { soft_limit_error = true; }
}
#else
// NOTE: max_travel is stored as negative
if (target[idx] > 0 || target[idx] < settings.max_travel[idx]) { soft_limit_error = true; }
#endif
if (soft_limit_error) {
// Force feed hold if cycle is active. All buffered blocks are guaranteed to be within
// workspace volume so just come to a controlled stop so position is not lost. When complete
// enter alarm mode.
if (sys.state == STATE_CYCLE) {
system_set_exec_state_flag(EXEC_FEED_HOLD);
do {
protocol_execute_realtime();
if (sys.abort) { return; }
} while ( sys.state != STATE_IDLE );
}
mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.
system_set_exec_alarm_flag((EXEC_ALARM_SOFT_LIMIT|EXEC_CRITICAL_EVENT)); // Indicate soft limit critical event
protocol_execute_realtime(); // Execute to enter critical event loop and system abort
return;
}
}
}
// Execute dwell in seconds.
void mc_dwell(float seconds)
{
if (sys.state == STATE_CHECK_MODE) { return; }
uint16_t i = floor(1000/DWELL_TIME_STEP*seconds);
protocol_buffer_synchronize();
delay_ms(floor(1000*seconds-i*DWELL_TIME_STEP)); // Delay millisecond remainder.
while (i-- > 0) {
// NOTE: Check and execute realtime commands during dwell every <= DWELL_TIME_STEP milliseconds.
protocol_execute_realtime();
if (sys.abort) { return; }
_delay_ms(DWELL_TIME_STEP); // Delay DWELL_TIME_STEP increment
}
}
// Perform homing cycle to locate and set machine zero. Only '$H' executes this command.
// NOTE: There should be no motions in the buffer and Grbl must be in an idle state before
// executing the homing cycle. This prevents incorrect buffered plans after homing.
void mc_homing_cycle()
{
// Check and abort homing cycle, if hard limits are already enabled. Helps prevent problems
// with machines with limits wired on both ends of travel to one limit pin.
// TODO: Move the pin-specific LIMIT_PIN call to limits.c as a function.
#ifdef LIMITS_TWO_SWITCHES_ON_AXES
if (limits_get_state()) {
mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.
bit_true_atomic(sys_rt_exec_alarm, (EXEC_ALARM_HARD_LIMIT|EXEC_CRITICAL_EVENT));
return;
}
#endif
limits_disable(); // Disable hard limits pin change register for cycle duration
// -------------------------------------------------------------------------------------
// Perform homing routine. NOTE: Special motion case. Only system reset works.
// Search to engage all axes limit switches at faster homing seek rate.
limits_go_home(HOMING_CYCLE_0); // Homing cycle 0
#ifdef HOMING_CYCLE_1
limits_go_home(HOMING_CYCLE_1); // Homing cycle 1
#endif
#ifdef HOMING_CYCLE_2
limits_go_home(HOMING_CYCLE_2); // Homing cycle 2
#endif
#ifdef HOMING_CYCLE_3
limits_go_home(HOMING_CYCLE_3); // Homing cycle 3
#endif
#ifdef HOMING_CYCLE_4
limits_go_home(HOMING_CYCLE_4); // Homing cycle 4
#endif
#ifdef HOMING_CYCLE_5
limits_go_home(HOMING_CYCLE_5); // Homing cycle 5
#endif
protocol_execute_realtime(); // Check for reset and set system abort.
if (sys.abort) { return; } // Did not complete. Alarm state set by mc_alarm.
// Homing cycle complete! Setup system for normal operation.
// -------------------------------------------------------------------------------------
// Gcode parser position was circumvented by the limits_go_home() routine, so sync position now.
gc_sync_position();
// If hard limits feature enabled, re-enable hard limits pin change register after homing cycle.
limits_init();
}
// Perform homing cycle to locate and set machine zero. Only '$H' executes this command.
// NOTE: There should be no motions in the buffer and Grbl must be in an idle state before
// executing the homing cycle. This prevents incorrect buffered plans after homing.
void mc_homing_cycle(uint8_t cycle_mask)
{
// Check and abort homing cycle, if hard limits are already enabled. Helps prevent problems
// with machines with limits wired on both ends of travel to one limit pin.
// TODO: Move the pin-specific LIMIT_PIN call to limits.c as a function.
#ifdef LIMITS_TWO_SWITCHES_ON_AXES
if (limits_get_state()) {
mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.
system_set_exec_alarm(EXEC_ALARM_HARD_LIMIT);
return;
}
#endif
limits_disable(); // Disable hard limits pin change register for cycle duration
// -------------------------------------------------------------------------------------
// Perform homing routine. NOTE: Special motion case. Only system reset works.
#ifdef HOMING_SINGLE_AXIS_COMMANDS
if (cycle_mask) { limits_go_home(cycle_mask); } // Perform homing cycle based on mask.
else
#endif
{
// Search to engage all axes limit switches at faster homing seek rate.
limits_go_home(HOMING_CYCLE_0); // Homing cycle 0
#ifdef HOMING_CYCLE_1
limits_go_home(HOMING_CYCLE_1); // Homing cycle 1
#endif
#ifdef HOMING_CYCLE_2
limits_go_home(HOMING_CYCLE_2); // Homing cycle 2
#endif
}
protocol_execute_realtime(); // Check for reset and set system abort.
if (sys.abort) { return; } // Did not complete. Alarm state set by mc_alarm.
// Homing cycle complete! Setup system for normal operation.
// -------------------------------------------------------------------------------------
// Sync gcode parser and planner positions to homed position.
gc_sync_position();
plan_sync_position();
// If hard limits feature enabled, re-enable hard limits pin change register after homing cycle.
limits_init();
}
void punch()
{
if (sys.state == STATE_CHECK_MODE) {
return ;
}
punch_stop();
// wait for current awaited commands
protocol_buffer_synchronize();
// wait for the end of move
do {
protocol_execute_realtime();
if (sys.abort) {
return;
}
} while ( sys.state != STATE_IDLE );
punch_activate_actuator(COMMAND_PUNCH_UNACTIVATED);
punch_activate_actuator(COMMAND_PUNCH_DOWN);
// wait_a_bit();
punch_wait_sensor_state(PUNCH_SENSOR_DOWN_BIT);
// wait_a_bit();
punch_activate_actuator(COMMAND_PUNCH_UNACTIVATED);
// wait_a_bit();
// activate the punch up
punch_activate_actuator(COMMAND_PUNCH_UP);
// wait_a_bit();
// activate the punch up, and release the down
punch_wait_sensor_state(PUNCH_SENSOR_UP_BIT);
// wait_a_bit();
}
void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate)
#endif
{
// If enabled, check for soft limit violations. Placed here all line motions are picked up
// from everywhere in Grbl.
if (bit_istrue(settings.flags,BITFLAG_SOFT_LIMIT_ENABLE)) { limits_soft_check(target); }
// If in check gcode mode, prevent motion by blocking planner. Soft limits still work.
if (sys.state == STATE_CHECK_MODE) { return; }
// NOTE: Backlash compensation may be installed here. It will need direction info to track when
// to insert a backlash line motion(s) before the intended line motion and will require its own
// plan_check_full_buffer() and check for system abort loop. Also for position reporting
// backlash steps will need to be also tracked, which will need to be kept at a system level.
// There are likely some other things that will need to be tracked as well. However, we feel
// that backlash compensation should NOT be handled by Grbl itself, because there are a myriad
// of ways to implement it and can be effective or ineffective for different CNC machines. This
// would be better handled by the interface as a post-processor task, where the original g-code
// is translated and inserts backlash motions that best suits the machine.
// NOTE: Perhaps as a middle-ground, all that needs to be sent is a flag or special command that
// indicates to Grbl what is a backlash compensation motion, so that Grbl executes the move but
// doesn't update the machine position values. Since the position values used by the g-code
// parser and planner are separate from the system machine positions, this is doable.
// If the buffer is full: good! That means we are well ahead of the robot.
// Remain in this loop until there is room in the buffer.
do {
protocol_execute_realtime(); // Check for any run-time commands
if (sys.abort) { return; } // Bail, if system abort.
if ( plan_check_full_buffer() ) { protocol_auto_cycle_start(); } // Auto-cycle start when buffer is full.
else { break; }
} while (1);
// Plan and queue motion into planner buffer
#ifdef USE_LINE_NUMBERS
plan_buffer_line(target, feed_rate, invert_feed_rate, line_number);
#else
plan_buffer_line(target, feed_rate, invert_feed_rate);
#endif
}
// Directs and executes one line of formatted input from protocol_process. While mostly
// incoming streaming g-code blocks, this also executes Grbl internal commands, such as
// settings, initiating the homing cycle, and toggling switch states. This differs from
// the realtime command module by being susceptible to when Grbl is ready to execute the
// next line during a cycle, so for switches like block delete, the switch only effects
// the lines that are processed afterward, not necessarily real-time during a cycle,
// since there are motions already stored in the buffer. However, this 'lag' should not
// be an issue, since these commands are not typically used during a cycle.
uint8_t system_execute_line(char *line)
{
uint8_t char_counter = 1;
uint8_t helper_var = 0; // Helper variable
float parameter, value;
switch( line[char_counter] ) {
case 0 : report_grbl_help(); break;
case '$': case 'G': case 'C': case 'X':
if ( line[(char_counter+1)] != 0 ) { return(STATUS_INVALID_STATEMENT); }
switch( line[char_counter] ) {
case '$' : // Prints Grbl settings
if ( sys.state & (STATE_CYCLE | STATE_HOLD) ) { return(STATUS_IDLE_ERROR); } // Block during cycle. Takes too long to print.
else { report_grbl_settings(); }
break;
case 'G' : // Prints gcode parser state
// TODO: Move this to realtime commands for GUIs to request this data during suspend-state.
report_gcode_modes();
break;
case 'C' : // Set check g-code mode [IDLE/CHECK]
// Perform reset when toggling off. Check g-code mode should only work if Grbl
// is idle and ready, regardless of alarm locks. This is mainly to keep things
// simple and consistent.
if ( sys.state == STATE_CHECK_MODE ) {
mc_reset();
report_feedback_message(MESSAGE_DISABLED);
} else {
if (sys.state) { return(STATUS_IDLE_ERROR); } // Requires no alarm mode.
sys.state = STATE_CHECK_MODE;
report_feedback_message(MESSAGE_ENABLED);
}
break;
case 'X' : // Disable alarm lock [ALARM]
if (sys.state == STATE_ALARM) {
report_feedback_message(MESSAGE_ALARM_UNLOCK);
sys.state = STATE_IDLE;
// Don't run startup script. Prevents stored moves in startup from causing accidents.
#ifndef DEFAULTS_TRINAMIC
if (system_check_safety_door_ajar()) { // Check safety door switch before returning.
bit_true(sys_rt_exec_state, EXEC_SAFETY_DOOR);
protocol_execute_realtime(); // Enter safety door mode.
}
#endif
} // Otherwise, no effect.
break;
// case 'J' : break; // Jogging methods
// TODO: Here jogging can be placed for execution as a seperate subprogram. It does not need to be
// susceptible to other realtime commands except for e-stop. The jogging function is intended to
// be a basic toggle on/off with controlled acceleration and deceleration to prevent skipped
// steps. The user would supply the desired feedrate, axis to move, and direction. Toggle on would
// start motion and toggle off would initiate a deceleration to stop. One could 'feather' the
// motion by repeatedly toggling to slow the motion to the desired location. Location data would
// need to be updated real-time and supplied to the user through status queries.
// More controlled exact motions can be taken care of by inputting G0 or G1 commands, which are
// handled by the planner. It would be possible for the jog subprogram to insert blocks into the
// block buffer without having the planner plan them. It would need to manage de/ac-celerations
// on its own carefully. This approach could be effective and possibly size/memory efficient.
// }
// break;
}
break;
default :
// Block any system command that requires the state as IDLE/ALARM. (i.e. EEPROM, homing)
if ( !(sys.state == STATE_IDLE || sys.state == STATE_ALARM) ) { return(STATUS_IDLE_ERROR); }
switch( line[char_counter] ) {
case '#' : // Print Grbl NGC parameters
if ( line[++char_counter] != 0 ) { return(STATUS_INVALID_STATEMENT); }
else { report_ngc_parameters(); }
break;
case 'H' : // Perform homing cycle [IDLE/ALARM]
if (bit_istrue(settings.flags,BITFLAG_HOMING_ENABLE)) {
sys.state = STATE_HOMING; // Set system state variable
// Only perform homing if Grbl is idle or lost.
// TODO: Likely not required.
#ifndef DEFAULTS_TRINAMIC
if (system_check_safety_door_ajar()) { // Check safety door switch before homing.
bit_true(sys_rt_exec_state, EXEC_SAFETY_DOOR);
protocol_execute_realtime(); // Enter safety door mode.
}
#endif
mc_homing_cycle();
if (!sys.abort) { // Execute startup scripts after successful homing.
sys.state = STATE_IDLE; // Set to IDLE when complete.
st_go_idle(); // Set steppers to the settings idle state before returning.
system_execute_startup(line);
}
} else { return(STATUS_SETTING_DISABLED); }
break;
case 'I' : // Print or store build info. [IDLE/ALARM]
if ( line[++char_counter] == 0 ) {
settings_read_build_info(line);
report_build_info(line);
} else { // Store startup line [IDLE/ALARM]
if(line[char_counter++] != '=') { return(STATUS_INVALID_STATEMENT); }
helper_var = char_counter; // Set helper variable as counter to start of user info line.
do {
line[char_counter-helper_var] = line[char_counter];
} while (line[char_counter++] != 0);
settings_store_build_info(line);
}
break;
case 'R' : // Restore defaults [IDLE/ALARM]
if (line[++char_counter] != 'S') { return(STATUS_INVALID_STATEMENT); }
if (line[++char_counter] != 'T') { return(STATUS_INVALID_STATEMENT); }
if (line[++char_counter] != '=') { return(STATUS_INVALID_STATEMENT); }
if (line[char_counter+2] != 0) { return(STATUS_INVALID_STATEMENT); }
switch (line[++char_counter]) {
case '$': settings_restore(SETTINGS_RESTORE_DEFAULTS); break;
case '#': settings_restore(SETTINGS_RESTORE_PARAMETERS); break;
case '*': settings_restore(SETTINGS_RESTORE_ALL); break;
default: return(STATUS_INVALID_STATEMENT);
}
report_feedback_message(MESSAGE_RESTORE_DEFAULTS);
mc_reset(); // Force reset to ensure settings are initialized correctly.
break;
case 'N' : // Startup lines. [IDLE/ALARM]
if ( line[++char_counter] == 0 ) { // Print startup lines
for (helper_var=0; helper_var < N_STARTUP_LINE; helper_var++) {
if (!(settings_read_startup_line(helper_var, line))) {
report_status_message(STATUS_SETTING_READ_FAIL);
} else {
report_startup_line(helper_var,line);
}
}
break;
} else { // Store startup line [IDLE Only] Prevents motion during ALARM.
if (sys.state != STATE_IDLE) { return(STATUS_IDLE_ERROR); } // Store only when idle.
helper_var = true; // Set helper_var to flag storing method.
// No break. Continues into default: to read remaining command characters.
}
default : // Storing setting methods [IDLE/ALARM]
if(!read_float(line, &char_counter, ¶meter)) { return(STATUS_BAD_NUMBER_FORMAT); }
if(line[char_counter++] != '=') { return(STATUS_INVALID_STATEMENT); }
if (helper_var) { // Store startup line
// Prepare sending gcode block to gcode parser by shifting all characters
helper_var = char_counter; // Set helper variable as counter to start of gcode block
do {
line[char_counter-helper_var] = line[char_counter];
} while (line[char_counter++] != 0);
// Execute gcode block to ensure block is valid.
helper_var = gc_execute_line(line); // Set helper_var to returned status code.
if (helper_var) { return(helper_var); }
else {
helper_var = trunc(parameter); // Set helper_var to int value of parameter
settings_store_startup_line(helper_var,line);
}
} else { // Store global setting.
if(!read_float(line, &char_counter, &value)) { return(STATUS_BAD_NUMBER_FORMAT); }
if((line[char_counter] != 0) || (parameter > 255)) { return(STATUS_INVALID_STATEMENT); }
return(settings_store_global_setting((uint8_t)parameter, value));
}
}
}
return(STATUS_OK); // If '$' command makes it to here, then everything's ok.
}
void mc_probe_cycle(float *target, float feed_rate, uint8_t invert_feed_rate, uint8_t is_probe_away,
uint8_t is_no_error)
#endif
{
// TODO: Need to update this cycle so it obeys a non-auto cycle start.
if (sys.state == STATE_CHECK_MODE) { return; }
// Finish all queued commands and empty planner buffer before starting probe cycle.
protocol_buffer_synchronize();
// Initialize probing control variables
sys.probe_succeeded = false; // Re-initialize probe history before beginning cycle.
probe_configure_invert_mask(is_probe_away);
// After syncing, check if probe is already triggered. If so, halt and issue alarm.
// NOTE: This probe initialization error applies to all probing cycles.
if ( probe_get_state() ) { // Check probe pin state.
bit_true_atomic(sys_rt_exec_alarm, EXEC_ALARM_PROBE_FAIL);
protocol_execute_realtime();
}
if (sys.abort) { return; } // Return if system reset has been issued.
// Setup and queue probing motion. Auto cycle-start should not start the cycle.
#ifdef USE_LINE_NUMBERS
mc_line(target, feed_rate, invert_feed_rate, line_number);
#else
mc_line(target, feed_rate, invert_feed_rate);
#endif
// Activate the probing state monitor in the stepper module.
sys_probe_state = PROBE_ACTIVE;
// Perform probing cycle. Wait here until probe is triggered or motion completes.
bit_true_atomic(sys_rt_exec_state, EXEC_CYCLE_START);
do {
protocol_execute_realtime();
if (sys.abort) { return; } // Check for system abort
} while (sys.state != STATE_IDLE);
// Probing cycle complete!
// Set state variables and error out, if the probe failed and cycle with error is enabled.
if (sys_probe_state == PROBE_ACTIVE) {
if (is_no_error) { memcpy(sys.probe_position, sys.position, sizeof(float)*N_AXIS); }
else { bit_true_atomic(sys_rt_exec_alarm, EXEC_ALARM_PROBE_FAIL); }
} else {
sys.probe_succeeded = true; // Indicate to system the probing cycle completed successfully.
}
sys_probe_state = PROBE_OFF; // Ensure probe state monitor is disabled.
protocol_execute_realtime(); // Check and execute run-time commands
if (sys.abort) { return; } // Check for system abort
// Reset the stepper and planner buffers to remove the remainder of the probe motion.
st_reset(); // Reest step segment buffer.
plan_reset(); // Reset planner buffer. Zero planner positions. Ensure probing motion is cleared.
plan_sync_position(); // Sync planner position to current machine position.
// TODO: Update the g-code parser code to not require this target calculation but uses a gc_sync_position() call.
// NOTE: The target[] variable updated here will be sent back and synced with the g-code parser.
system_convert_array_steps_to_mpos(target, sys.position);
#ifdef MESSAGE_PROBE_COORDINATES
// All done! Output the probe position as message.
report_probe_parameters();
#endif
}
// Perform tool length probe cycle. Requires probe switch.
// NOTE: Upon probe failure, the program will be stopped and placed into ALARM state.
uint8_t mc_probe_cycle(float *target, plan_line_data_t *pl_data, uint8_t parser_flags)
{
// TODO: Need to update this cycle so it obeys a non-auto cycle start.
if (sys.state == STATE_CHECK_MODE) { return(GC_PROBE_CHECK_MODE); }
// Finish all queued commands and empty planner buffer before starting probe cycle.
protocol_buffer_synchronize();
if (sys.abort) { return(GC_PROBE_ABORT); } // Return if system reset has been issued.
// Initialize probing control variables
uint8_t is_probe_away = bit_istrue(parser_flags,GC_PARSER_PROBE_IS_AWAY);
uint8_t is_no_error = bit_istrue(parser_flags,GC_PARSER_PROBE_IS_NO_ERROR);
sys.probe_succeeded = false; // Re-initialize probe history before beginning cycle.
probe_configure_invert_mask(is_probe_away);
// After syncing, check if probe is already triggered. If so, halt and issue alarm.
// NOTE: This probe initialization error applies to all probing cycles.
if ( probe_get_state() ) { // Check probe pin state.
system_set_exec_alarm(EXEC_ALARM_PROBE_FAIL_INITIAL);
protocol_execute_realtime();
probe_configure_invert_mask(false); // Re-initialize invert mask before returning.
return(GC_PROBE_FAIL_INIT); // Nothing else to do but bail.
}
// Setup and queue probing motion. Auto cycle-start should not start the cycle.
mc_line(target, pl_data);
// Activate the probing state monitor in the stepper module.
sys_probe_state = PROBE_ACTIVE;
// Perform probing cycle. Wait here until probe is triggered or motion completes.
system_set_exec_state_flag(EXEC_CYCLE_START);
do {
protocol_execute_realtime();
if (sys.abort) { return(GC_PROBE_ABORT); } // Check for system abort
} while (sys.state != STATE_IDLE);
// Probing cycle complete!
// Set state variables and error out, if the probe failed and cycle with error is enabled.
if (sys_probe_state == PROBE_ACTIVE) {
if (is_no_error) { memcpy(sys_probe_position, sys_position, sizeof(sys_position)); }
else { system_set_exec_alarm(EXEC_ALARM_PROBE_FAIL_CONTACT); }
} else {
sys.probe_succeeded = true; // Indicate to system the probing cycle completed successfully.
}
sys_probe_state = PROBE_OFF; // Ensure probe state monitor is disabled.
probe_configure_invert_mask(false); // Re-initialize invert mask.
protocol_execute_realtime(); // Check and execute run-time commands
// Reset the stepper and planner buffers to remove the remainder of the probe motion.
st_reset(); // Reset step segment buffer.
plan_reset(); // Reset planner buffer. Zero planner positions. Ensure probing motion is cleared.
plan_sync_position(); // Sync planner position to current machine position.
#ifdef MESSAGE_PROBE_COORDINATES
// All done! Output the probe position as message.
report_probe_parameters();
#endif
if (sys.probe_succeeded) { return(GC_PROBE_FOUND); } // Successful probe cycle.
else { return(GC_PROBE_FAIL_END); } // Failed to trigger probe within travel. With or without error.
}
// Homes the specified cycle axes, sets the machine position, and performs a pull-off motion after
// completing. Homing is a special motion case, which involves rapid uncontrolled stops to locate
// the trigger point of the limit switches. The rapid stops are handled by a system level axis lock
// mask, which prevents the stepper algorithm from executing step pulses. Homing motions typically
// circumvent the processes for executing motions in normal operation.
// NOTE: Only the abort realtime command can interrupt this process.
// TODO: Move limit pin-specific calls to a general function for portability.
void limits_go_home(uint8_t cycle_mask)
{
if (sys.abort) { return; } // Block if system reset has been issued.
// Initialize
uint8_t n_cycle = (2*N_HOMING_LOCATE_CYCLE+1);
uint8_t step_pin[N_AXIS];
float target[N_AXIS];
float max_travel = 0.0;
uint8_t idx;
for (idx=0; idx<N_AXIS; idx++) {
// Initialize step pin masks
step_pin[idx] = get_step_pin_mask(idx);
#ifdef COREXY
if ((idx==A_MOTOR)||(idx==B_MOTOR)) { step_pin[idx] = (get_step_pin_mask(X_AXIS)|get_step_pin_mask(Y_AXIS)); }
#endif
if (bit_istrue(cycle_mask,bit(idx))) {
// Set target based on max_travel setting. Ensure homing switches engaged with search scalar.
// NOTE: settings.max_travel[] is stored as a negative value.
max_travel = max(max_travel,(-HOMING_AXIS_SEARCH_SCALAR)*settings.max_travel[idx]);
}
}
// Set search mode with approach at seek rate to quickly engage the specified cycle_mask limit switches.
bool approach = true;
float homing_rate = settings.homing_seek_rate;
uint8_t limit_state, axislock, n_active_axis;
do {
system_convert_array_steps_to_mpos(target,sys.position);
// Initialize and declare variables needed for homing routine.
axislock = 0;
n_active_axis = 0;
for (idx=0; idx<N_AXIS; idx++) {
// Set target location for active axes and setup computation for homing rate.
if (bit_istrue(cycle_mask,bit(idx))) {
n_active_axis++;
sys.position[idx] = 0;
// Set target direction based on cycle mask and homing cycle approach state.
// NOTE: This happens to compile smaller than any other implementation tried.
if (bit_istrue(settings.homing_dir_mask,bit(idx))) {
if (approach) { target[idx] = -max_travel; }
else { target[idx] = max_travel; }
} else {
if (approach) { target[idx] = max_travel; }
else { target[idx] = -max_travel; }
}
// Apply axislock to the step port pins active in this cycle.
axislock |= step_pin[idx];
}
}
homing_rate *= sqrt(n_active_axis); // [sqrt(N_AXIS)] Adjust so individual axes all move at homing rate.
sys.homing_axis_lock = axislock;
plan_sync_position(); // Sync planner position to current machine position.
// Perform homing cycle. Planner buffer should be empty, as required to initiate the homing cycle.
#ifdef USE_LINE_NUMBERS
plan_buffer_line(target, homing_rate, false, false, HOMING_CYCLE_LINE_NUMBER); // Bypass mc_line(). Directly plan homing motion.
#else
plan_buffer_line(target, homing_rate, false, false); // Bypass mc_line(). Directly plan homing motion.
#endif
st_prep_buffer(); // Prep and fill segment buffer from newly planned block.
st_wake_up(); // Initiate motion
do {
if (approach) {
// Check limit state. Lock out cycle axes when they change.
limit_state = limits_get_state();
for (idx=0; idx<N_AXIS; idx++) {
if (axislock & step_pin[idx]) {
if (limit_state & (1 << idx)) { axislock &= ~(step_pin[idx]); }
}
}
sys.homing_axis_lock = axislock;
}
st_prep_buffer(); // Check and prep segment buffer. NOTE: Should take no longer than 200us.
// Exit routines: No time to run protocol_execute_realtime() in this loop.
if (sys_rt_exec_state & (EXEC_SAFETY_DOOR | EXEC_RESET | EXEC_CYCLE_STOP)) {
// Homing failure: Limit switches are still engaged after pull-off motion
if ( (sys_rt_exec_state & (EXEC_SAFETY_DOOR | EXEC_RESET)) || // Safety door or reset issued
(!approach && (limits_get_state() & cycle_mask)) || // Limit switch still engaged after pull-off motion
( approach && (sys_rt_exec_state & EXEC_CYCLE_STOP)) ) { // Limit switch not found during approach.
mc_reset(); // Stop motors, if they are running.
protocol_execute_realtime();
return;
} else {
// Pull-off motion complete. Disable CYCLE_STOP from executing.
system_clear_exec_state_flag(EXEC_CYCLE_STOP);
break;
}
}
} while (STEP_MASK & axislock);
st_reset(); // Immediately force kill steppers and reset step segment buffer.
plan_reset(); // Reset planner buffer to zero planner current position and to clear previous motions.
delay_ms(settings.homing_debounce_delay); // Delay to allow transient dynamics to dissipate.
// Reverse direction and reset homing rate for locate cycle(s).
approach = !approach;
// After first cycle, homing enters locating phase. Shorten search to pull-off distance.
if (approach) {
max_travel = settings.homing_pulloff*HOMING_AXIS_LOCATE_SCALAR;
homing_rate = settings.homing_feed_rate;
} else {
max_travel = settings.homing_pulloff;
homing_rate = settings.homing_seek_rate;
}
} while (n_cycle-- > 0);
// The active cycle axes should now be homed and machine limits have been located. By
// default, Grbl defines machine space as all negative, as do most CNCs. Since limit switches
// can be on either side of an axes, check and set axes machine zero appropriately. Also,
// set up pull-off maneuver from axes limit switches that have been homed. This provides
// some initial clearance off the switches and should also help prevent them from falsely
// triggering when hard limits are enabled or when more than one axes shares a limit pin.
#ifdef COREXY
int32_t off_axis_position = 0;
#endif
int32_t set_axis_position;
// Set machine positions for homed limit switches. Don't update non-homed axes.
for (idx=0; idx<N_AXIS; idx++) {
// NOTE: settings.max_travel[] is stored as a negative value.
if (cycle_mask & bit(idx)) {
#ifdef HOMING_FORCE_SET_ORIGIN
set_axis_position = 0;
#else
if ( bit_istrue(settings.homing_dir_mask,bit(idx)) ) {
set_axis_position = lround((settings.max_travel[idx]+settings.homing_pulloff)*settings.steps_per_mm[idx]);
} else {
set_axis_position = lround(-settings.homing_pulloff*settings.steps_per_mm[idx]);
}
#endif
#ifdef COREXY
if (idx==X_AXIS) {
off_axis_position = (sys.position[B_MOTOR] - sys.position[A_MOTOR])/2;
sys.position[A_MOTOR] = set_axis_position - off_axis_position;
sys.position[B_MOTOR] = set_axis_position + off_axis_position;
} else if (idx==Y_AXIS) {
off_axis_position = (sys.position[A_MOTOR] + sys.position[B_MOTOR])/2;
sys.position[A_MOTOR] = off_axis_position - set_axis_position;
sys.position[B_MOTOR] = off_axis_position + set_axis_position;
} else {
sys.position[idx] = set_axis_position;
}
#else
sys.position[idx] = set_axis_position;
#endif
}
}
plan_sync_position(); // Sync planner position to homed machine position.
// sys.state = STATE_HOMING; // Ensure system state set as homing before returning.
}
/*
GRBL PRIMARY LOOP:
*/
void protocol_main_loop()
{
// ------------------------------------------------------------
// Complete initialization procedures upon a power-up or reset.
// ------------------------------------------------------------
// Print welcome message
report_init_message();
// Check for and report alarm state after a reset, error, or an initial power up.
if (sys.state == STATE_ALARM) {
report_feedback_message(MESSAGE_ALARM_LOCK);
} else {
// All systems go! But first check for safety door.
#ifndef DEFAULTS_TRINAMIC
if (system_check_safety_door_ajar()) {
bit_true(sys_rt_exec_state, EXEC_SAFETY_DOOR);
protocol_execute_realtime(); // Enter safety door mode. Should return as IDLE state.
} else {
sys.state = STATE_IDLE; // Set system to ready. Clear all state flags.
}
#endif
system_execute_startup(line); // Execute startup script.
}
// ---------------------------------------------------------------------------------
// Primary loop! Upon a system abort, this exits back to main() to reset the system.
// ---------------------------------------------------------------------------------
uint8_t comment = COMMENT_NONE;
uint8_t char_counter = 0;
uint8_t c;
for (;;) {
// Process one line of incoming serial data, as the data becomes available. Performs an
// initial filtering by removing spaces and comments and capitalizing all letters.
// NOTE: While comment, spaces, and block delete(if supported) handling should technically
// be done in the g-code parser, doing it here helps compress the incoming data into Grbl's
// line buffer, which is limited in size. The g-code standard actually states a line can't
// exceed 256 characters, but the Arduino Uno does not have the memory space for this.
// With a better processor, it would be very easy to pull this initial parsing out as a
// seperate task to be shared by the g-code parser and Grbl's system commands.
while((c = serial_read()) != SERIAL_NO_DATA) {
if ((c == '\n') || (c == '\r')) { // End of line reached
line[char_counter] = 0; // Set string termination character.
protocol_execute_line(line); // Line is complete. Execute it!
comment = COMMENT_NONE;
char_counter = 0;
} else {
if (comment != COMMENT_NONE) {
// Throw away all comment characters
if (c == ')') {
// End of comment. Resume line. But, not if semicolon type comment.
if (comment == COMMENT_TYPE_PARENTHESES) { comment = COMMENT_NONE; }
}
} else {
if (c <= ' ') {
// Throw away whitepace and control characters
} else if (c == '/') {
// Block delete NOT SUPPORTED. Ignore character.
// NOTE: If supported, would simply need to check the system if block delete is enabled.
} else if (c == '(') {
// Enable comments flag and ignore all characters until ')' or EOL.
// NOTE: This doesn't follow the NIST definition exactly, but is good enough for now.
// In the future, we could simply remove the items within the comments, but retain the
// comment control characters, so that the g-code parser can error-check it.
comment = COMMENT_TYPE_PARENTHESES;
} else if (c == ';') {
// NOTE: ';' comment to EOL is a LinuxCNC definition. Not NIST.
comment = COMMENT_TYPE_SEMICOLON;
// TODO: Install '%' feature
// } else if (c == '%') {
// Program start-end percent sign NOT SUPPORTED.
// NOTE: This maybe installed to tell Grbl when a program is running vs manual input,
// where, during a program, the system auto-cycle start will continue to execute
// everything until the next '%' sign. This will help fix resuming issues with certain
// functions that empty the planner buffer to execute its task on-time.
} else if (char_counter >= (LINE_BUFFER_SIZE-1)) {
// Detect line buffer overflow. Report error and reset line buffer.
report_status_message(STATUS_OVERFLOW);
comment = COMMENT_NONE;
char_counter = 0;
} else if (c >= 'a' && c <= 'z') { // Upcase lowercase
line[char_counter++] = c-'a'+'A';
} else {
line[char_counter++] = c;
}
}
}
}
// If there are no more characters in the serial read buffer to be processed and executed,
// this indicates that g-code streaming has either filled the planner buffer or has
// completed. In either case, auto-cycle start, if enabled, any queued moves.
protocol_auto_cycle_start();
protocol_execute_realtime(); // Runtime command check point.
if (sys.abort) { return; } // Bail to main() program loop to reset system.
}
return; /* Never reached */
}
