Import grbl v1.1h
diff --git a/grbl/limits.c b/grbl/limits.c
new file mode 100644
index 0000000..1348c14
--- /dev/null
+++ b/grbl/limits.c
@@ -0,0 +1,430 @@
+/*
+ limits.c - code pertaining to limit-switches and performing the homing cycle
+ Part of Grbl
+
+ Copyright (c) 2012-2016 Sungeun K. Jeon for Gnea Research LLC
+ Copyright (c) 2009-2011 Simen Svale Skogsrud
+
+ 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 <http://www.gnu.org/licenses/>.
+*/
+
+#include "grbl.h"
+
+
+// Homing axis search distance multiplier. Computed by this value times the cycle travel.
+#ifndef HOMING_AXIS_SEARCH_SCALAR
+ #define HOMING_AXIS_SEARCH_SCALAR 1.5 // Must be > 1 to ensure limit switch will be engaged.
+#endif
+#ifndef HOMING_AXIS_LOCATE_SCALAR
+ #define HOMING_AXIS_LOCATE_SCALAR 5.0 // Must be > 1 to ensure limit switch is cleared.
+#endif
+
+#ifdef ENABLE_DUAL_AXIS
+ // Flags for dual axis async limit trigger check.
+ #define DUAL_AXIS_CHECK_DISABLE 0 // Must be zero
+ #define DUAL_AXIS_CHECK_ENABLE bit(0)
+ #define DUAL_AXIS_CHECK_TRIGGER_1 bit(1)
+ #define DUAL_AXIS_CHECK_TRIGGER_2 bit(2)
+#endif
+
+void limits_init()
+{
+ LIMIT_DDR &= ~(LIMIT_MASK); // Set as input pins
+
+ #ifdef DISABLE_LIMIT_PIN_PULL_UP
+ LIMIT_PORT &= ~(LIMIT_MASK); // Normal low operation. Requires external pull-down.
+ #else
+ LIMIT_PORT |= (LIMIT_MASK); // Enable internal pull-up resistors. Normal high operation.
+ #endif
+
+ if (bit_istrue(settings.flags,BITFLAG_HARD_LIMIT_ENABLE)) {
+ LIMIT_PCMSK |= LIMIT_MASK; // Enable specific pins of the Pin Change Interrupt
+ PCICR |= (1 << LIMIT_INT); // Enable Pin Change Interrupt
+ } else {
+ limits_disable();
+ }
+
+ #ifdef ENABLE_SOFTWARE_DEBOUNCE
+ MCUSR &= ~(1<<WDRF);
+ WDTCSR |= (1<<WDCE) | (1<<WDE);
+ WDTCSR = (1<<WDP0); // Set time-out at ~32msec.
+ #endif
+}
+
+
+// Disables hard limits.
+void limits_disable()
+{
+ LIMIT_PCMSK &= ~LIMIT_MASK; // Disable specific pins of the Pin Change Interrupt
+ PCICR &= ~(1 << LIMIT_INT); // Disable Pin Change Interrupt
+}
+
+
+// Returns limit state as a bit-wise uint8 variable. Each bit indicates an axis limit, where
+// triggered is 1 and not triggered is 0. Invert mask is applied. Axes are defined by their
+// number in bit position, i.e. Z_AXIS is (1<<2) or bit 2, and Y_AXIS is (1<<1) or bit 1.
+uint8_t limits_get_state()
+{
+ uint8_t limit_state = 0;
+ uint8_t pin = (LIMIT_PIN & LIMIT_MASK);
+ #ifdef INVERT_LIMIT_PIN_MASK
+ pin ^= INVERT_LIMIT_PIN_MASK;
+ #endif
+ if (bit_isfalse(settings.flags,BITFLAG_INVERT_LIMIT_PINS)) { pin ^= LIMIT_MASK; }
+ if (pin) {
+ uint8_t idx;
+ for (idx=0; idx<N_AXIS; idx++) {
+ if (pin & get_limit_pin_mask(idx)) { limit_state |= (1 << idx); }
+ }
+ #ifdef ENABLE_DUAL_AXIS
+ if (pin & (1<<DUAL_LIMIT_BIT)) { limit_state |= (1 << N_AXIS); }
+ #endif
+ }
+ return(limit_state);
+}
+
+
+// This is the Limit Pin Change Interrupt, which handles the hard limit feature. A bouncing
+// limit switch can cause a lot of problems, like false readings and multiple interrupt calls.
+// If a switch is triggered at all, something bad has happened and treat it as such, regardless
+// if a limit switch is being disengaged. It's impossible to reliably tell the state of a
+// bouncing pin because the Arduino microcontroller does not retain any state information when
+// detecting a pin change. If we poll the pins in the ISR, you can miss the correct reading if the
+// switch is bouncing.
+// NOTE: Do not attach an e-stop to the limit pins, because this interrupt is disabled during
+// homing cycles and will not respond correctly. Upon user request or need, there may be a
+// special pinout for an e-stop, but it is generally recommended to just directly connect
+// your e-stop switch to the Arduino reset pin, since it is the most correct way to do this.
+#ifndef ENABLE_SOFTWARE_DEBOUNCE
+ ISR(LIMIT_INT_vect) // DEFAULT: Limit pin change interrupt process.
+ {
+ // Ignore limit switches if already in an alarm state or in-process of executing an alarm.
+ // When in the alarm state, Grbl should have been reset or will force a reset, so any pending
+ // moves in the planner and serial buffers are all cleared and newly sent blocks will be
+ // locked out until a homing cycle or a kill lock command. Allows the user to disable the hard
+ // limit setting if their limits are constantly triggering after a reset and move their axes.
+ if (sys.state != STATE_ALARM) {
+ if (!(sys_rt_exec_alarm)) {
+ #ifdef HARD_LIMIT_FORCE_STATE_CHECK
+ // Check limit pin state.
+ if (limits_get_state()) {
+ mc_reset(); // Initiate system kill.
+ system_set_exec_alarm(EXEC_ALARM_HARD_LIMIT); // Indicate hard limit critical event
+ }
+ #else
+ mc_reset(); // Initiate system kill.
+ system_set_exec_alarm(EXEC_ALARM_HARD_LIMIT); // Indicate hard limit critical event
+ #endif
+ }
+ }
+ }
+#else // OPTIONAL: Software debounce limit pin routine.
+ // Upon limit pin change, enable watchdog timer to create a short delay.
+ ISR(LIMIT_INT_vect) { if (!(WDTCSR & (1<<WDIE))) { WDTCSR |= (1<<WDIE); } }
+ ISR(WDT_vect) // Watchdog timer ISR
+ {
+ WDTCSR &= ~(1<<WDIE); // Disable watchdog timer.
+ if (sys.state != STATE_ALARM) { // Ignore if already in alarm state.
+ if (!(sys_rt_exec_alarm)) {
+ // Check limit pin state.
+ if (limits_get_state()) {
+ mc_reset(); // Initiate system kill.
+ system_set_exec_alarm(EXEC_ALARM_HARD_LIMIT); // Indicate hard limit critical event
+ }
+ }
+ }
+ }
+#endif
+
+// 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 plan data struct for homing motion. Spindle and coolant are disabled.
+ plan_line_data_t plan_data;
+ plan_line_data_t *pl_data = &plan_data;
+ memset(pl_data,0,sizeof(plan_line_data_t));
+ pl_data->condition = (PL_COND_FLAG_SYSTEM_MOTION|PL_COND_FLAG_NO_FEED_OVERRIDE);
+ #ifdef USE_LINE_NUMBERS
+ pl_data->line_number = HOMING_CYCLE_LINE_NUMBER;
+ #endif
+
+ // Initialize variables used for homing computations.
+ uint8_t n_cycle = (2*N_HOMING_LOCATE_CYCLE+1);
+ uint8_t step_pin[N_AXIS];
+ #ifdef ENABLE_DUAL_AXIS
+ uint8_t step_pin_dual;
+ uint8_t dual_axis_async_check;
+ int32_t dual_trigger_position;
+ #if (DUAL_AXIS_SELECT == X_AXIS)
+ float fail_distance = (-DUAL_AXIS_HOMING_FAIL_AXIS_LENGTH_PERCENT/100.0)*settings.max_travel[Y_AXIS];
+ #else
+ float fail_distance = (-DUAL_AXIS_HOMING_FAIL_AXIS_LENGTH_PERCENT/100.0)*settings.max_travel[X_AXIS];
+ #endif
+ fail_distance = min(fail_distance, DUAL_AXIS_HOMING_FAIL_DISTANCE_MAX);
+ fail_distance = max(fail_distance, DUAL_AXIS_HOMING_FAIL_DISTANCE_MIN);
+ int32_t dual_fail_distance = trunc(fail_distance*settings.steps_per_mm[DUAL_AXIS_SELECT]);
+ // int32_t dual_fail_distance = trunc((DUAL_AXIS_HOMING_TRIGGER_FAIL_DISTANCE)*settings.steps_per_mm[DUAL_AXIS_SELECT]);
+ #endif
+ 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]);
+ }
+ }
+ #ifdef ENABLE_DUAL_AXIS
+ step_pin_dual = (1<<DUAL_STEP_BIT);
+ #endif
+
+ // 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;
+ #ifdef ENABLE_DUAL_AXIS
+ sys.homing_axis_lock_dual = 0;
+ dual_trigger_position = 0;
+ dual_axis_async_check = DUAL_AXIS_CHECK_DISABLE;
+ #endif
+ 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++;
+ #ifdef COREXY
+ if (idx == X_AXIS) {
+ int32_t axis_position = system_convert_corexy_to_y_axis_steps(sys_position);
+ sys_position[A_MOTOR] = axis_position;
+ sys_position[B_MOTOR] = -axis_position;
+ } else if (idx == Y_AXIS) {
+ int32_t axis_position = system_convert_corexy_to_x_axis_steps(sys_position);
+ sys_position[A_MOTOR] = sys_position[B_MOTOR] = axis_position;
+ } else {
+ sys_position[Z_AXIS] = 0;
+ }
+ #else
+ sys_position[idx] = 0;
+ #endif
+ // 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];
+ #ifdef ENABLE_DUAL_AXIS
+ if (idx == DUAL_AXIS_SELECT) { sys.homing_axis_lock_dual = step_pin_dual; }
+ #endif
+ }
+
+ }
+ homing_rate *= sqrt(n_active_axis); // [sqrt(N_AXIS)] Adjust so individual axes all move at homing rate.
+ sys.homing_axis_lock = axislock;
+
+ // Perform homing cycle. Planner buffer should be empty, as required to initiate the homing cycle.
+ pl_data->feed_rate = homing_rate; // Set current homing rate.
+ plan_buffer_line(target, pl_data); // Bypass mc_line(). Directly plan homing motion.
+
+ sys.step_control = STEP_CONTROL_EXECUTE_SYS_MOTION; // Set to execute homing motion and clear existing flags.
+ 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)) {
+ #ifdef COREXY
+ if (idx==Z_AXIS) { axislock &= ~(step_pin[Z_AXIS]); }
+ else { axislock &= ~(step_pin[A_MOTOR]|step_pin[B_MOTOR]); }
+ #else
+ axislock &= ~(step_pin[idx]);
+ #ifdef ENABLE_DUAL_AXIS
+ if (idx == DUAL_AXIS_SELECT) { dual_axis_async_check |= DUAL_AXIS_CHECK_TRIGGER_1; }
+ #endif
+ #endif
+ }
+ }
+ }
+ sys.homing_axis_lock = axislock;
+ #ifdef ENABLE_DUAL_AXIS
+ if (sys.homing_axis_lock_dual) { // NOTE: Only true when homing dual axis.
+ if (limit_state & (1 << N_AXIS)) {
+ sys.homing_axis_lock_dual = 0;
+ dual_axis_async_check |= DUAL_AXIS_CHECK_TRIGGER_2;
+ }
+ }
+
+ // When first dual axis limit triggers, record position and begin checking distance until other limit triggers. Bail upon failure.
+ if (dual_axis_async_check) {
+ if (dual_axis_async_check & DUAL_AXIS_CHECK_ENABLE) {
+ if (( dual_axis_async_check & (DUAL_AXIS_CHECK_TRIGGER_1 | DUAL_AXIS_CHECK_TRIGGER_2)) == (DUAL_AXIS_CHECK_TRIGGER_1 | DUAL_AXIS_CHECK_TRIGGER_2)) {
+ dual_axis_async_check = DUAL_AXIS_CHECK_DISABLE;
+ } else {
+ if (abs(dual_trigger_position - sys_position[DUAL_AXIS_SELECT]) > dual_fail_distance) {
+ system_set_exec_alarm(EXEC_ALARM_HOMING_FAIL_DUAL_APPROACH);
+ mc_reset();
+ protocol_execute_realtime();
+ return;
+ }
+ }
+ } else {
+ dual_axis_async_check |= DUAL_AXIS_CHECK_ENABLE;
+ dual_trigger_position = sys_position[DUAL_AXIS_SELECT];
+ }
+ }
+ #endif
+ }
+
+ 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)) {
+ uint8_t rt_exec = sys_rt_exec_state;
+ // Homing failure condition: Reset issued during cycle.
+ if (rt_exec & EXEC_RESET) { system_set_exec_alarm(EXEC_ALARM_HOMING_FAIL_RESET); }
+ // Homing failure condition: Safety door was opened.
+ if (rt_exec & EXEC_SAFETY_DOOR) { system_set_exec_alarm(EXEC_ALARM_HOMING_FAIL_DOOR); }
+ // Homing failure condition: Limit switch still engaged after pull-off motion
+ if (!approach && (limits_get_state() & cycle_mask)) { system_set_exec_alarm(EXEC_ALARM_HOMING_FAIL_PULLOFF); }
+ // Homing failure condition: Limit switch not found during approach.
+ if (approach && (rt_exec & EXEC_CYCLE_STOP)) { system_set_exec_alarm(EXEC_ALARM_HOMING_FAIL_APPROACH); }
+ if (sys_rt_exec_alarm) {
+ 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;
+ }
+ }
+
+ #ifdef ENABLE_DUAL_AXIS
+ } while ((STEP_MASK & axislock) || (sys.homing_axis_lock_dual));
+ #else
+ } while (STEP_MASK & axislock);
+ #endif
+
+ st_reset(); // Immediately force kill steppers and reset step segment buffer.
+ 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.
+ 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) {
+ int32_t off_axis_position = system_convert_corexy_to_y_axis_steps(sys_position);
+ 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) {
+ int32_t off_axis_position = system_convert_corexy_to_x_axis_steps(sys_position);
+ 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
+
+ }
+ }
+ sys.step_control = STEP_CONTROL_NORMAL_OP; // Return step control to normal operation.
+}
+
+
+// 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.
+// NOTE: Used by jogging to limit travel within soft-limit volume.
+void limits_soft_check(float *target)
+{
+ if (system_check_travel_limits(target)) {
+ sys.soft_limit = true;
+ // 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(EXEC_ALARM_SOFT_LIMIT); // Indicate soft limit critical event
+ protocol_execute_realtime(); // Execute to enter critical event loop and system abort
+ return;
+ }
+}