// Execute linear motion in absolute millimeter coordinates. Feed rate given in millimeters/second
// unless invert_feed_rate is true. Then the feed_rate means that the motion should be completed in
// (1 minute)/feed_rate time.
// NOTE: This is the primary gateway to the grbl planner. All line motions, including arc line
// segments, must pass through this routine before being passed to the planner. The seperation of
// mc_line and plan_buffer_line is done primarily to make backlash compensation integration simple
// and direct.
// TODO: Check for a better way to avoid having to push the arguments twice for non-backlash cases.
// However, this keeps the memory requirements lower since it doesn't have to call and hold two
// plan_buffer_lines in memory. Grbl only has to retain the original line input variables during a
// backlash segment(s).
void mc_line(double x, double y, double z, double c, double feed_rate, uint8_t invert_feed_rate)
{
// TODO: Backlash compensation may be installed here. Only need direction info to track when
// to insert a backlash line motion(s) before the intended line motion. Requires its own
// plan_check_full_buffer() and check for system abort loop. Also for position reporting
// backlash steps will need to be also tracked. Not sure what the best strategy is for this,
// i.e. keep the planner independent and do the computations in the status reporting, or let
// the planner handle the position corrections. The latter may get complicated.
// 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_runtime(); // Check for any run-time commands
if (sys.abort) { return; } // Bail, if system abort.
} while ( plan_check_full_buffer() );
plan_buffer_line(x, y, z, c, feed_rate, invert_feed_rate);
// Auto-cycle start immediately after planner finishes. Enabled/disabled by grbl settings. During
// a feed hold, auto-start is disabled momentarily until the cycle is resumed by the cycle-start
// runtime command.
// NOTE: This is allows the user to decide to exclusively use the cycle start runtime command to
// begin motion or let grbl auto-start it for them. This is useful when: manually cycle-starting
// when the buffer is completely full and primed; auto-starting, if there was only one g-code
// command sent during manual operation; or if a system is prone to buffer starvation, auto-start
// helps make sure it minimizes any dwelling/motion hiccups and keeps the cycle going.
if (sys.auto_start) { st_cycle_start(); }
}
// 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_go_home()
{
sys.state = STATE_HOMING; // Set system state variable
LIMIT_PCMSK &= ~LIMIT_MASK; // Disable hard limits pin change register for cycle duration
limits_go_home(); // Perform homing routine.
protocol_execute_runtime(); // Check for reset and set system abort.
if (sys.abort) { return; } // Did not complete. Alarm state set by mc_alarm.
// The machine should now be homed and machine zero has been located. Upon completion,
// reset system position and sync internal position vectors.
clear_vector_float(sys.position); // Set machine zero
sys_sync_current_position();
sys.state = STATE_IDLE; // Set system state to IDLE to complete motion and indicate homed.
// Pull-off axes (that have been homed) from limit switches before continuing motion.
// This provides some initial clearance off the switches and should also help prevent them
// from falsely tripping when hard limits are enabled.
/// 8c1
int8_t x_dir, y_dir, z_dir, t_dir;
x_dir = y_dir = z_dir = t_dir = 0;
if (HOMING_LOCATE_CYCLE & (1<<X_AXIS)) {
if (settings.homing_dir_mask & (1<<X_DIRECTION_BIT))
x_dir = 1;
else
x_dir = -1;
}
if (HOMING_LOCATE_CYCLE & (1<<Y_AXIS)) {
if (settings.homing_dir_mask & (1<<Y_DIRECTION_BIT)) { y_dir = 1; }
else { y_dir = -1; }
}
if (HOMING_LOCATE_CYCLE & (1<<Z_AXIS)) {
if (settings.homing_dir_mask & (1<<Z_DIRECTION_BIT)) { z_dir = 1; }
else { z_dir = -1; }
}
/// 8c1
if (HOMING_LOCATE_CYCLE & (1<<T_AXIS)) {
if (settings.homing_dir_mask & (1<<T_DIRECTION_BIT)) { t_dir = 1; }
else { t_dir = -1; }
}
/// 8c1 : line
mc_line(x_dir*settings.homing_pulloff, y_dir*settings.homing_pulloff,
z_dir*settings.homing_pulloff, t_dir*settings.homing_pulloff, settings.homing_seek_rate, false, C_LINE);
st_cycle_start(); // Move it. Nothing should be in the buffer except this motion.
plan_synchronize(); // Make sure the motion completes.
// The gcode parser position circumvented by the pull-off maneuver, so sync position vectors.
sys_sync_current_position();
// If hard limits feature enabled, re-enable hard limits pin change register after homing cycle.
if (bit_istrue(settings.flags,BITFLAG_HARD_LIMIT_ENABLE))
LIMIT_PCMSK |= LIMIT_MASK;
// Finished!
}
// Returns the availability status of the block ring buffer. True, if full.
uint8_t plan_check_full_buffer()
{
if (block_buffer_tail == next_buffer_head) {
// TODO: Move this back into motion control. Shouldn't be here, but it's efficient.
if (sys.auto_start) { st_cycle_start(); } // Auto-cycle start when buffer is full.
return(true);
}
return(false);
}
// 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 to handles them, removing the need to
// define more computationally-expensive volatile variables.
// NOTE: The sys.execute variable flags are set by the serial read subprogram, except where noted.
void protocol_execute_runtime()
{
// evaluate emergency stop -cm
if (!(AUX_PIN & (1<<AUX_STOP_BIT)))
{
if (!(sys.execute & EXEC_RESET)) { // Force stop only first time.
st_go_idle();
spindle_stop();
sys.execute |= EXEC_RESET; // Set as true
}
}
if (sys.execute) { // Enter only if any bit flag is true
uint8_t rt_exec = sys.execute; // Avoid calling volatile multiple times
// System abort. Steppers have already been force stopped.
if (rt_exec & EXEC_RESET) {
sys.abort = true;
return; // Nothing else to do but exit.
}
// Execute and serial print status
if (rt_exec & EXEC_STATUS_REPORT) {
protocol_status_report();
bit_false(sys.execute,EXEC_STATUS_REPORT);
}
// Execute and serial print switches
if (rt_exec & EXEC_SWITCH_REPORT) {
protocol_switch_report();
bit_false(sys.execute,EXEC_SWITCH_REPORT);
}
// Initiate stepper feed hold
if (rt_exec & EXEC_FEED_HOLD) {
st_feed_hold(); // Initiate feed hold.
bit_false(sys.execute,EXEC_FEED_HOLD);
}
// Reinitializes the stepper module running flags and re-plans the buffer after a feed hold.
// NOTE: EXEC_CYCLE_STOP is set by the stepper subsystem when a cycle or feed hold completes.
if (rt_exec & EXEC_CYCLE_STOP) {
st_cycle_reinitialize();
bit_false(sys.execute,EXEC_CYCLE_STOP);
}
if (rt_exec & EXEC_CYCLE_START) {
st_cycle_start(); // Issue cycle start command to stepper subsystem
#ifdef CYCLE_AUTO_START
sys.auto_start = true; // Re-enable auto start after feed hold.
#endif
bit_false(sys.execute,EXEC_CYCLE_START);
}
}
}
// 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_go_home()
{
sys.state = STATE_HOMING; // Set system state variable
LIMIT_PCMSK &= ~LIMIT_MASK; // Disable hard limits pin change register for cycle duration
limits_go_home(); // Perform homing routine.
protocol_execute_runtime(); // Check for reset and set system abort.
if (sys.abort) { return; } // Did not complete. Alarm state set by mc_alarm.
// The machine 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 machine zero appropriately.
// At the same time, 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 tripping when hard limits are enabled.
// TODO: Need to improve dir_mask[] to be more axes independent.
float pulloff_target[N_AXIS];
clear_vector_float(pulloff_target); // Zero pulloff target.
clear_vector_long(sys.position); // Zero current position for now.
uint8_t dir_mask[N_AXIS];
dir_mask[X_AXIS] = (1<<X_DIRECTION_BIT);
dir_mask[Y_AXIS] = (1<<Y_DIRECTION_BIT);
dir_mask[Z_AXIS] = (1<<Z_DIRECTION_BIT);
uint8_t i;
for (i=0; i<N_AXIS; i++) {
// Set up pull off targets and machine positions for limit switches homed in the negative
// direction, rather than the traditional positive. Leave non-homed positions as zero and
// do not move them.
if (HOMING_LOCATE_CYCLE & bit(i)) {
if (settings.homing_dir_mask & dir_mask[i]) {
pulloff_target[i] = settings.homing_pulloff-settings.max_travel[i];
sys.position[i] = -lround(settings.max_travel[i]*settings.steps_per_mm[i]);
} else {
pulloff_target[i] = -settings.homing_pulloff;
}
}
}
sys_sync_current_position();
sys.state = STATE_IDLE; // Set system state to IDLE to complete motion and indicate homed.
mc_line(pulloff_target, settings.homing_seek_rate, false);
st_cycle_start(); // Move it. Nothing should be in the buffer except this motion.
plan_synchronize(); // Make sure the motion completes.
// The gcode parser position circumvented by the pull-off maneuver, so sync position vectors.
sys_sync_current_position();
// If hard limits feature enabled, re-enable hard limits pin change register after homing cycle.
if (bit_istrue(settings.flags,BITFLAG_HARD_LIMIT_ENABLE)) { LIMIT_PCMSK |= LIMIT_MASK; }
// Finished!
}
// Execute linear motion in absolute millimeter coordinates. Feed rate given in millimeters/second
// unless invert_feed_rate is true. Then the feed_rate means that the motion should be completed in
// (1 minute)/feed_rate time.
// NOTE: This is the primary gateway to the grbl planner. All line motions, including arc line
// segments, must pass through this routine before being passed to the planner. The seperation of
// mc_line and plan_buffer_line is done primarily to make backlash compensation integration simple
// and direct.
// TODO: Check for a better way to avoid having to push the arguments twice for non-backlash cases.
// However, this keeps the memory requirements lower since it doesn't have to call and hold two
// plan_buffer_lines in memory. Grbl only has to retain the original line input variables during a
// backlash segment(s).
void mc_line(float x, float y, float z, float feed_rate, uint8_t invert_feed_rate)
{
// TODO: Perform soft limit check here. Just check if the target x,y,z values are outside the
// work envelope. Should be straightforward and efficient. By placing it here, rather than in
// the g-code parser, it directly picks up motions from everywhere in Grbl.
// If in check gcode mode, prevent motion by blocking planner.
if (sys.state == STATE_CHECK_MODE) {
return;
}
// TODO: Backlash compensation may be installed here. Only need direction info to track when
// to insert a backlash line motion(s) before the intended line motion. Requires its own
// plan_check_full_buffer() and check for system abort loop. Also for position reporting
// backlash steps will need to be also tracked. Not sure what the best strategy is for this,
// i.e. keep the planner independent and do the computations in the status reporting, or let
// the planner handle the position corrections. The latter may get complicated.
// 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_runtime(); // Check for any run-time commands
if (sys.abort) {
return; // Bail, if system abort.
}
} while ( plan_check_full_buffer() );
plan_buffer_line(x, y, z, feed_rate, invert_feed_rate);
// If idle, indicate to the system there is now a planned block in the buffer ready to cycle
// start. Otherwise ignore and continue on.
if (!sys.state) {
sys.state = STATE_QUEUED;
}
// Auto-cycle start immediately after planner finishes. Enabled/disabled by grbl settings. During
// a feed hold, auto-start is disabled momentarily until the cycle is resumed by the cycle-start
// runtime command.
// NOTE: This is allows the user to decide to exclusively use the cycle start runtime command to
// begin motion or let grbl auto-start it for them. This is useful when: manually cycle-starting
// when the buffer is completely full and primed; auto-starting, if there was only one g-code
// command sent during manual operation; or if a system is prone to buffer starvation, auto-start
// helps make sure it minimizes any dwelling/motion hiccups and keeps the cycle going.
if (sys.auto_start) {
st_cycle_start();
}
}
// 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 protocol_execute_runtime()
{
if (sys.execute) { // Enter only if any bit flag is true
uint8_t rt_exec = sys.execute; // Avoid calling volatile multiple times
// 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)) {
sys.state = STATE_ALARM; // Set system alarm state
// Critical event. Only hard limit qualifies. Update this as new critical events surface.
if (rt_exec & EXEC_CRIT_EVENT) {
report_alarm_message(ALARM_HARD_LIMIT);
report_feedback_message(MESSAGE_CRITICAL_EVENT);
bit_false(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.
} while (bit_isfalse(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.
report_alarm_message(ALARM_ABORT_CYCLE);
}
bit_false(sys.execute,(EXEC_ALARM | EXEC_CRIT_EVENT));
}
// 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(sys.execute,EXEC_STATUS_REPORT);
}
// Initiate stepper feed hold
if (rt_exec & EXEC_FEED_HOLD) {
st_feed_hold(); // Initiate feed hold.
bit_false(sys.execute,EXEC_FEED_HOLD);
}
// Reinitializes the stepper module running state and, if a feed hold, re-plans the buffer.
// NOTE: EXEC_CYCLE_STOP is set by the stepper subsystem when a cycle or feed hold completes.
if (rt_exec & EXEC_CYCLE_STOP) {
st_cycle_reinitialize();
bit_false(sys.execute,EXEC_CYCLE_STOP);
}
if (rt_exec & EXEC_CYCLE_START) {
st_cycle_start(); // Issue cycle start command to stepper subsystem
if (bit_istrue(settings.flags,BITFLAG_AUTO_START)) {
sys.auto_start = true; // Re-enable auto start after feed hold.
}
bit_false(sys.execute,EXEC_CYCLE_START);
}
}
// 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.
}
// Auto-cycle start is a user setting that automatically begins the cycle when a user enters
// a valid motion command either manually or by a streaming tool. This is intended as a beginners
// feature to help new users to understand g-code. It can be disabled. Otherwise, the normal
// operation of cycle start is manually issuing a cycle start command whenever the user is
// ready and there is a valid motion command in the planner queue.
// NOTE: This function is called from the main loop and mc_line() only and executes when one of
// two conditions exist respectively: There are no more blocks sent (i.e. streaming is finished,
// single commands), or the planner buffer is full and ready to go.
void mc_auto_cycle_start() { if (sys.auto_start) { st_cycle_start(); } }
int main(void)
{
#ifdef PART_LM4F120H5QR // ARM code
SysCtlClockSet( SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN ); //set system clock to 80 MHz
FPUEnable(); //enable the Floating Point Unit
// FPULazyStackingEnable(); // Enable stacking for interrupt handlers
#endif
// Initialize system
serial_init(); // Setup serial baud rate and interrupts
settings_init(); // Load grbl settings from EEPROM
st_init(); // Setup stepper pins and interrupt timers
#ifdef PART_LM4F120H5QR // ARM code
IntMasterEnable();
#else // AVR code
sei(); // Enable interrupts
#endif
memset(&sys, 0, sizeof(sys)); // Clear all system variables
sys.abort = true; // Set abort to complete initialization
sys.state = STATE_INIT; // Set alarm state to indicate unknown initial position
for(;;) {
// Execute system reset upon a system abort, where the main program will return to this loop.
// Once here, it is safe to re-initialize the system. At startup, the system will automatically
// reset to finish the initialization process.
if (sys.abort) {
// Reset system.
serial_reset_read_buffer(); // Clear serial read buffer
plan_init(); // Clear block buffer and planner variables
gc_init(); // Set g-code parser to default state
protocol_init(); // Clear incoming line data and execute startup lines
spindle_init();
coolant_init();
limits_init();
st_reset(); // Clear stepper subsystem variables.
// Sync cleared gcode and planner positions to current system position, which is only
// cleared upon startup, not a reset/abort.
sys_sync_current_position();
// Reset system variables.
sys.abort = false;
sys.execute = 0;
if (bit_istrue(settings.flags,BITFLAG_AUTO_START)) { sys.auto_start = true; }
// Check for power-up and set system alarm if homing is enabled to force homing cycle
// by setting Grbl's alarm state. Alarm locks out all g-code commands, including the
// startup scripts, but allows access to settings and internal commands. Only a homing
// cycle '$H' or kill alarm locks '$X' will disable the alarm.
// NOTE: The startup script will run after successful completion of the homing cycle, but
// not after disabling the alarm locks. Prevents motion startup blocks from crashing into
// things uncontrollably. Very bad.
#ifdef HOMING_INIT_LOCK
if (sys.state == STATE_INIT && bit_istrue(settings.flags,BITFLAG_HOMING_ENABLE)) { sys.state = STATE_ALARM; }
#endif
// 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. Set system to ready and execute startup script.
sys.state = STATE_IDLE;
protocol_execute_startup();
}
}
protocol_execute_runtime();
protocol_process(); // ... process the serial protocol
// When the serial protocol returns, there are no more characters in the serial read buffer to
// be processed and executed. This indicates that individual commands are being issued or
// streaming is finished. In either case, auto-cycle start, if enabled, any queued moves.
if (sys.auto_start) { st_cycle_start(); }
}
// return 0; /* never reached */
}
void protocol_execute_runtime()
{
uint8_t aux_bits;
aux_bits = AUX_PIN ^ AUX_INVMASK; // apply invert mask
if (!(aux_bits & (1<<AUX_STOP_BIT)))
{
if (!(emerg_stop)) {
st_go_idle();
spindle_stop();
sys.abort = true;
emerg_stop = true;
}
}
else {
emerg_stop = false;
}
AUX_PORT ^= (1<<AUX_WDOG_BIT); // Chargepump-Bit invertieren
if (sys.execute) { // Enter only if any bit flag is true
uint8_t rt_exec = sys.execute; // Avoid calling volatile multiple times
// System abort. Steppers have already been force stopped.
if (rt_exec & EXEC_RESET) {
sys.abort = true;
return; // Nothing else to do but exit.
}
// Execute and serial print status
if (rt_exec & EXEC_STATUS_REPORT) {
protocol_status_report();
bit_false(sys.execute,EXEC_STATUS_REPORT);
}
// Execute and serial print switches
if (rt_exec & EXEC_SWITCH_REPORT) {
protocol_switch_report();
bit_false(sys.execute,EXEC_SWITCH_REPORT);
}
// Initiate stepper feed hold
if (rt_exec & EXEC_FEED_HOLD) {
st_feed_hold(); // Initiate feed hold.
bit_false(sys.execute,EXEC_FEED_HOLD);
}
// Reinitializes the stepper module running flags and re-plans the buffer after a feed hold.
// NOTE: EXEC_CYCLE_STOP is set by the stepper subsystem when a cycle or feed hold completes.
if (rt_exec & EXEC_CYCLE_STOP) {
st_cycle_reinitialize();
bit_false(sys.execute,EXEC_CYCLE_STOP);
}
if (rt_exec & EXEC_CYCLE_START) {
st_cycle_start(); // Issue cycle start command to stepper subsystem
#ifdef CYCLE_AUTO_START
sys.auto_start = true; // Re-enable auto start after feed hold.
#endif
bit_false(sys.execute,EXEC_CYCLE_START);
}
}
}
