// Executes run-time commands, when required. This is called from various check points in the main
// program, primarily where there may be a while loop waiting for a buffer to clear space or any
// point where the execution time from the last check point may be more than a fraction of a second.
// This is a way to execute realtime commands asynchronously (aka multitasking) with grbl's g-code
// parsing and planning functions. This function also serves as an interface for the interrupts to
// set the system realtime flags, where only the main program handles them, removing the need to
// define more computationally-expensive volatile variables. This also provides a controlled way to
// execute certain tasks without having two or more instances of the same task, such as the planner
// recalculating the buffer upon a feedhold or override.
// NOTE: The sys_rt_exec_state variable flags are set by any process, step or serial interrupts, pinouts,
// limit switches, or the main program.
void protocol_execute_realtime()
{
uint8_t rt_exec; // Temp variable to avoid calling volatile multiple times.
do { // If system is suspended, suspend loop restarts here.
// Check and execute alarms.
rt_exec = sys_rt_exec_alarm; // Copy volatile sys_rt_exec_alarm.
if (rt_exec) { // Enter only if any bit flag is true
// System alarm. Everything has shutdown by something that has gone severely wrong. Report
// the source of the error to the user. If critical, Grbl disables by entering an infinite
// loop until system reset/abort.
sys.state = STATE_ALARM; // Set system alarm state
if (rt_exec & EXEC_ALARM_HARD_LIMIT) {
report_alarm_message(ALARM_HARD_LIMIT_ERROR);
} else if (rt_exec & EXEC_ALARM_SOFT_LIMIT) {
report_alarm_message(ALARM_SOFT_LIMIT_ERROR);
} else if (rt_exec & EXEC_ALARM_ABORT_CYCLE) {
report_alarm_message(ALARM_ABORT_CYCLE);
} else if (rt_exec & EXEC_ALARM_PROBE_FAIL) {
report_alarm_message(ALARM_PROBE_FAIL);
} else if (rt_exec & EXEC_ALARM_HOMING_FAIL) {
report_alarm_message(ALARM_HOMING_FAIL);
}
// Halt everything upon a critical event flag. Currently hard and soft limits flag this.
if (rt_exec & EXEC_CRITICAL_EVENT) {
report_feedback_message(MESSAGE_CRITICAL_EVENT);
bit_false_atomic(sys_rt_exec_state,EXEC_RESET); // Disable any existing reset
do {
// Nothing. Block EVERYTHING until user issues reset or power cycles. Hard limits
// typically occur while unattended or not paying attention. Gives the user time
// to do what is needed before resetting, like killing the incoming stream. The
// same could be said about soft limits. While the position is not lost, the incoming
// stream could be still engaged and cause a serious crash if it continues afterwards.
// TODO: Allow status reports during a critical alarm. Still need to think about implications of this.
// if (sys_rt_exec_state & EXEC_STATUS_REPORT) {
// report_realtime_status();
// bit_false_atomic(sys_rt_exec_state,EXEC_STATUS_REPORT);
// }
} while (bit_isfalse(sys_rt_exec_state,EXEC_RESET));
}
bit_false_atomic(sys_rt_exec_alarm,0xFF); // Clear all alarm flags
}
// Check amd execute realtime commands
rt_exec = sys_rt_exec_state; // Copy volatile sys_rt_exec_state.
if (rt_exec) { // Enter only if any bit flag is true
// Execute system abort.
if (rt_exec & EXEC_RESET) {
sys.abort = true; // Only place this is set true.
return; // Nothing else to do but exit.
}
// Execute and serial print status
if (rt_exec & EXEC_STATUS_REPORT) {
report_realtime_status();
bit_false_atomic(sys_rt_exec_state,EXEC_STATUS_REPORT);
}
// Execute hold states.
// NOTE: The math involved to calculate the hold should be low enough for most, if not all,
// operational scenarios. Once hold is initiated, the system enters a suspend state to block
// all main program processes until either reset or resumed.
if (rt_exec & (EXEC_MOTION_CANCEL | EXEC_FEED_HOLD | EXEC_SAFETY_DOOR)) {
// TODO: CHECK MODE? How to handle this? Likely nothing, since it only works when IDLE and then resets Grbl.
// State check for allowable states for hold methods.
if ((sys.state == STATE_IDLE) || (sys.state & (STATE_CYCLE | STATE_HOMING | STATE_MOTION_CANCEL | STATE_HOLD | STATE_SAFETY_DOOR))) {
// If in CYCLE state, all hold states immediately initiate a motion HOLD.
if (sys.state == STATE_CYCLE) {
st_update_plan_block_parameters(); // Notify stepper module to recompute for hold deceleration.
sys.suspend = SUSPEND_ENABLE_HOLD; // Initiate holding cycle with flag.
}
// If IDLE, Grbl is not in motion. Simply indicate suspend ready state.
if (sys.state == STATE_IDLE) { sys.suspend = SUSPEND_ENABLE_READY; }
// Execute and flag a motion cancel with deceleration and return to idle. Used primarily by probing cycle
// to halt and cancel the remainder of the motion.
if (rt_exec & EXEC_MOTION_CANCEL) {
// MOTION_CANCEL only occurs during a CYCLE, but a HOLD and SAFETY_DOOR may been initiated beforehand
// to hold the CYCLE. If so, only flag that motion cancel is complete.
if (sys.state == STATE_CYCLE) { sys.state = STATE_MOTION_CANCEL; }
sys.suspend |= SUSPEND_MOTION_CANCEL; // Indicate motion cancel when resuming. Special motion complete.
}
// Execute a feed hold with deceleration, only during cycle.
if (rt_exec & EXEC_FEED_HOLD) {
// Block SAFETY_DOOR state from prematurely changing back to HOLD.
if (bit_isfalse(sys.state,STATE_SAFETY_DOOR)) { sys.state = STATE_HOLD; }
}
// Execute a safety door stop with a feed hold, only during a cycle, and disable spindle/coolant.
// NOTE: Safety door differs from feed holds by stopping everything no matter state, disables powered
// devices (spindle/coolant), and blocks resuming until switch is re-engaged. The power-down is
// executed here, if IDLE, or when the CYCLE completes via the EXEC_CYCLE_STOP flag.
if (rt_exec & EXEC_SAFETY_DOOR) {
report_feedback_message(MESSAGE_SAFETY_DOOR_AJAR);
// If already in active, ready-to-resume HOLD, set CYCLE_STOP flag to force de-energize.
// NOTE: Only temporarily sets the 'rt_exec' variable, not the volatile 'rt_exec_state' variable.
if (sys.suspend & SUSPEND_ENABLE_READY) { bit_true(rt_exec,EXEC_CYCLE_STOP); }
sys.suspend |= SUSPEND_ENERGIZE;
sys.state = STATE_SAFETY_DOOR;
}
}
bit_false_atomic(sys_rt_exec_state,(EXEC_MOTION_CANCEL | EXEC_FEED_HOLD | EXEC_SAFETY_DOOR));
}
// Execute a cycle start by starting the stepper interrupt to begin executing the blocks in queue.
if (rt_exec & EXEC_CYCLE_START) {
// Block if called at same time as the hold commands: feed hold, motion cancel, and safety door.
// Ensures auto-cycle-start doesn't resume a hold without an explicit user-input.
if (!(rt_exec & (EXEC_FEED_HOLD | EXEC_MOTION_CANCEL | EXEC_SAFETY_DOOR))) {
// Cycle start only when IDLE or when a hold is complete and ready to resume.
// NOTE: SAFETY_DOOR is implicitly blocked. It reverts to HOLD when the door is closed.
if ((sys.state == STATE_IDLE) || ((sys.state & (STATE_HOLD | STATE_MOTION_CANCEL)) && (sys.suspend & SUSPEND_ENABLE_READY))) {
// Re-energize powered components, if disabled by SAFETY_DOOR.
if (sys.suspend & SUSPEND_ENERGIZE) {
// Delayed Tasks: Restart spindle and coolant, delay to power-up, then resume cycle.
if (gc_state.modal.spindle != SPINDLE_DISABLE) {
spindle_set_state(gc_state.modal.spindle, gc_state.spindle_speed);
delay_ms(SAFETY_DOOR_SPINDLE_DELAY); // TODO: Blocking function call. Need a non-blocking one eventually.
}
if (gc_state.modal.coolant != COOLANT_DISABLE) {
coolant_set_state(gc_state.modal.coolant);
delay_ms(SAFETY_DOOR_COOLANT_DELAY); // TODO: Blocking function call. Need a non-blocking one eventually.
}
// TODO: Install return to pre-park position.
}
// Start cycle only if queued motions exist in planner buffer and the motion is not canceled.
if (plan_get_current_block() && bit_isfalse(sys.suspend,SUSPEND_MOTION_CANCEL)) {
sys.state = STATE_CYCLE;
st_prep_buffer(); // Initialize step segment buffer before beginning cycle.
st_wake_up();
} else { // Otherwise, do nothing. Set and resume IDLE state.
sys.state = STATE_IDLE;
}
sys.suspend = SUSPEND_DISABLE; // Break suspend state.
}
}
bit_false_atomic(sys_rt_exec_state,EXEC_CYCLE_START);
}
// Reinitializes the cycle plan and stepper system after a feed hold for a resume. Called by
// realtime command execution in the main program, ensuring that the planner re-plans safely.
// NOTE: Bresenham algorithm variables are still maintained through both the planner and stepper
// cycle reinitializations. The stepper path should continue exactly as if nothing has happened.
// NOTE: EXEC_CYCLE_STOP is set by the stepper subsystem when a cycle or feed hold completes.
if (rt_exec & EXEC_CYCLE_STOP) {
if (sys.state & (STATE_HOLD | STATE_SAFETY_DOOR)) {
// Hold complete. Set to indicate ready to resume. Remain in HOLD or DOOR states until user
// has issued a resume command or reset.
if (sys.suspend & SUSPEND_ENERGIZE) { // De-energize system if safety door has been opened.
spindle_stop();
coolant_stop();
// TODO: Install parking motion here.
}
bit_true(sys.suspend,SUSPEND_ENABLE_READY);
} else { // Motion is complete. Includes CYCLE, HOMING, and MOTION_CANCEL states.
sys.suspend = SUSPEND_DISABLE;
sys.state = STATE_IDLE;
}
bit_false_atomic(sys_rt_exec_state,EXEC_CYCLE_STOP);
}
}
// Overrides flag byte (sys.override) and execution should be installed here, since they
// are realtime and require a direct and controlled interface to the main stepper program.
// Reload step segment buffer
if (sys.state & (STATE_CYCLE | STATE_HOLD | STATE_MOTION_CANCEL | STATE_SAFETY_DOOR | STATE_HOMING)) { st_prep_buffer(); }
// If safety door was opened, actively check when safety door is closed and ready to resume.
// NOTE: This unlocks the SAFETY_DOOR state to a HOLD state, such that CYCLE_START can activate a resume.
if (sys.state == STATE_SAFETY_DOOR) {
if (bit_istrue(sys.suspend,SUSPEND_ENABLE_READY)) {
#ifndef DEFAULTS_TRINAMIC
if (!(system_check_safety_door_ajar())) {
sys.state = STATE_HOLD; // Update to HOLD state to indicate door is closed and ready to resume.
}
#endif
}
}
} while(sys.suspend); // Check for system suspend state before exiting.
}
// 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, HOMING_CYCLE_LINE_NUMBER); // Bypass mc_line(). Directly plan homing motion.
#else
plan_buffer_line(target, homing_rate, 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.
bit_false_atomic(sys.rt_exec_state,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.
}
// Executes run-time commands, when required. This is called from various check points in the main
// program, primarily where there may be a while loop waiting for a buffer to clear space or any
// point where the execution time from the last check point may be more than a fraction of a second.
// This is a way to execute runtime commands asynchronously (aka multitasking) with grbl's g-code
// parsing and planning functions. This function also serves as an interface for the interrupts to
// set the system runtime flags, where only the main program handles them, removing the need to
// define more computationally-expensive volatile variables. This also provides a controlled way to
// execute certain tasks without having two or more instances of the same task, such as the planner
// recalculating the buffer upon a feedhold or override.
// NOTE: The sys.execute variable flags are set by any process, step or serial interrupts, pinouts,
// limit switches, or the main program.
void Grbl::Protocol::execute_runtime()
{
uint8_t rt_exec = parent->m_system.sys.execute; // Copy to avoid calling volatile multiple times
if (rt_exec) { // Enter only if any bit flag is true
// System alarm. Everything has shutdown by something that has gone severely wrong. Report
// the source of the error to the user. If critical, Grbl disables by entering an infinite
// loop until system reset/abort.
if (rt_exec & (EXEC_ALARM | EXEC_CRIT_EVENT)) {
parent->m_system.sys.state = STATE_ALARM; // Set system alarm state
// Critical events. Hard/soft limit events identified by both critical event and alarm exec
// flags. Probe fail is identified by the critical event exec flag only.
if (rt_exec & EXEC_CRIT_EVENT) {
if (rt_exec & EXEC_ALARM) { parent->m_report.alarm_message(ALARM_LIMIT_ERROR); }
else { parent->m_report.alarm_message(ALARM_PROBE_FAIL); }
parent->m_report.feedback_message(MESSAGE_CRITICAL_EVENT);
bit_false_atomic(parent->m_system.sys.execute,EXEC_RESET); // Disable any existing reset
do {
// Nothing. Block EVERYTHING until user issues reset or power cycles. Hard limits
// typically occur while unattended or not paying attention. Gives the user time
// to do what is needed before resetting, like killing the incoming stream. The
// same could be said about soft limits. While the position is not lost, the incoming
// stream could be still engaged and cause a serious crash if it continues afterwards.
} while (bit_isfalse(parent->m_system.sys.execute,EXEC_RESET));
// Standard alarm event. Only abort during motion qualifies.
} else {
// Runtime abort command issued during a cycle, feed hold, or homing cycle. Message the
// user that position may have been lost and set alarm state to enable the alarm lockout
// to indicate the possible severity of the problem.
parent->m_report.alarm_message(ALARM_ABORT_CYCLE);
}
bit_false_atomic(parent->m_system.sys.execute,(EXEC_ALARM | EXEC_CRIT_EVENT));
}
// Execute system abort.
if (rt_exec & EXEC_RESET) {
parent->m_system.sys.abort = true; // Only place this is set true.
return; // Nothing else to do but exit.
}
// Execute and serial print status
if (rt_exec & EXEC_STATUS_REPORT) {
parent->m_report.realtime_status();
bit_false_atomic(parent->m_system.sys.execute,EXEC_STATUS_REPORT);
}
// Execute a feed hold with deceleration, only during cycle.
if (rt_exec & EXEC_FEED_HOLD) {
// !!! During a cycle, the segment buffer has just been reloaded and full. So the math involved
// with the feed hold should be fine for most, if not all, operational scenarios.
if (parent->m_system.sys.state == STATE_CYCLE) {
parent->m_system.sys.state = STATE_HOLD;
parent->m_stepper.update_plan_block_parameters();
parent->m_stepper.prep_buffer();
parent->m_system.sys.auto_start = false; // Disable planner auto start upon feed hold.
}
bit_false_atomic(parent->m_system.sys.execute,EXEC_FEED_HOLD);
}
// Execute a cycle start by starting the stepper interrupt begin executing the blocks in queue.
if (rt_exec & EXEC_CYCLE_START) {
if (parent->m_system.sys.state == STATE_QUEUED) {
parent->m_system.sys.state = STATE_CYCLE;
parent->m_stepper.prep_buffer(); // Initialize step segment buffer before beginning cycle.
parent->m_stepper.wake_up();
if (bit_istrue(parent->m_settings.settings.flags,BITFLAG_AUTO_START)) {
parent->m_system.sys.auto_start = true; // Re-enable auto start after feed hold.
} else {
parent->m_system.sys.auto_start = false; // Reset auto start per settings.
}
}
bit_false_atomic(parent->m_system.sys.execute,EXEC_CYCLE_START);
}
// Reinitializes the cycle plan and stepper system after a feed hold for a resume. Called by
// runtime command execution in the main program, ensuring that the planner re-plans safely.
// NOTE: Bresenham algorithm variables are still maintained through both the planner and stepper
// cycle reinitializations. The stepper path should continue exactly as if nothing has happened.
// NOTE: EXEC_CYCLE_STOP is set by the stepper subsystem when a cycle or feed hold completes.
if (rt_exec & EXEC_CYCLE_STOP) {
if ( parent->m_plan.get_current_block() ) { parent->m_system.sys.state = STATE_QUEUED; }
else { parent->m_system.sys.state = STATE_IDLE; }
bit_false_atomic(parent->m_system.sys.execute,EXEC_CYCLE_STOP);
}
}
// Overrides flag byte (sys.override) and execution should be installed here, since they
// are runtime and require a direct and controlled interface to the main stepper program.
// Reload step segment buffer
if (parent->m_system.sys.state & (STATE_CYCLE | STATE_HOLD | STATE_HOMING)) { parent->m_stepper.prep_buffer(); }
}
