219 lines
9.0 KiB
C
219 lines
9.0 KiB
C
/*
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limits.c - code pertaining to limit-switches and performing the homing cycle
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Part of Grbl
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Copyright (c) 2009-2011 Simen Svale Skogsrud
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Copyright (c) 2012-2013 Sungeun K. Jeon
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Grbl is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Grbl is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Grbl. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <util/delay.h>
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <avr/wdt.h>
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#include "stepper.h"
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#include "settings.h"
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#include "nuts_bolts.h"
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#include "config.h"
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#include "spindle_control.h"
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#include "motion_control.h"
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#include "planner.h"
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#include "protocol.h"
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#include "limits.h"
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#include "report.h"
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void limits_init()
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{
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LIMIT_DDR &= ~(LIMIT_MASK); // Set as input pins
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#ifndef LIMIT_SWITCHES_ACTIVE_HIGH
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LIMIT_PORT |= (LIMIT_MASK); // Enable internal pull-up resistors. Normal high operation.
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#else
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LIMIT_PORT &= ~(LIMIT_MASK); // Normal low operation. Requires external pull-down.
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#endif
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if (bit_istrue(settings.flags,BITFLAG_HARD_LIMIT_ENABLE)) {
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LIMIT_PCMSK |= LIMIT_MASK; // Enable specific pins of the Pin Change Interrupt
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PCICR |= (1 << LIMIT_INT); // Enable Pin Change Interrupt
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} else {
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limits_disable();
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}
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#ifdef ENABLE_SOFTWARE_DEBOUNCE
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MCUSR &= ~(1<<WDRF);
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WDTCSR |= (1<<WDCE) | (1<<WDE);
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WDTCSR = (1<<WDP0);
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#endif
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}
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void limits_disable()
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{
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LIMIT_PCMSK &= ~LIMIT_MASK; // Disable specific pins of the Pin Change Interrupt
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PCICR &= ~(1 << LIMIT_INT); // Disable Pin Change Interrupt
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}
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// This is the Limit Pin Change Interrupt, which handles the hard limit feature. A bouncing
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// limit switch can cause a lot of problems, like false readings and multiple interrupt calls.
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// If a switch is triggered at all, something bad has happened and treat it as such, regardless
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// if a limit switch is being disengaged. It's impossible to reliably tell the state of a
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// bouncing pin without a debouncing method.
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// NOTE: Do not attach an e-stop to the limit pins, because this interrupt is disabled during
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// homing cycles and will not respond correctly. Upon user request or need, there may be a
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// special pinout for an e-stop, but it is generally recommended to just directly connect
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// your e-stop switch to the Arduino reset pin, since it is the most correct way to do this.
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#ifdef ENABLE_SOFTWARE_DEBOUNCE
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ISR(LIMIT_INT_vect) { if (!(WDTCSR & (1<<WDIE))) { WDTCSR |= (1<<WDIE); } }
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ISR(WDT_vect)
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{
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WDTCSR &= ~(1<<WDIE);
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// Ignore limit switches if already in an alarm state or in-process of executing an alarm.
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// When in the alarm state, Grbl should have been reset or will force a reset, so any pending
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// moves in the planner and serial buffers are all cleared and newly sent blocks will be
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// locked out until a homing cycle or a kill lock command. Allows the user to disable the hard
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// limit setting if their limits are constantly triggering after a reset and move their axes.
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if (sys.state != STATE_ALARM) {
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if (bit_isfalse(sys.execute,EXEC_ALARM)) {
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#ifndef LIMIT_SWITCHES_ACTIVE_HIGH
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if ((LIMIT_PIN & LIMIT_MASK) ^ LIMIT_MASK) {
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#else
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if (LIMIT_PIN & LIMIT_MASK) {
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#endif
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mc_reset(); // Initiate system kill.
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sys.execute |= EXEC_CRIT_EVENT; // Indicate hard limit critical event
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}
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}
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}
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}
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#else
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ISR(LIMIT_INT_vect)
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{
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// Ignore limit switches if already in an alarm state or in-process of executing an alarm.
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// When in the alarm state, Grbl should have been reset or will force a reset, so any pending
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// moves in the planner and serial buffers are all cleared and newly sent blocks will be
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// locked out until a homing cycle or a kill lock command. Allows the user to disable the hard
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// limit setting if their limits are constantly triggering after a reset and move their axes.
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if (sys.state != STATE_ALARM) {
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if (bit_isfalse(sys.execute,EXEC_ALARM)) {
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mc_reset(); // Initiate system kill.
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sys.execute |= EXEC_CRIT_EVENT; // Indicate hard limit critical event
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}
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}
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}
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#endif
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// Moves specified cycle axes all at homing rate, either approaching or disengaging the limit
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// switches. Homing is a special motion case, where there is only an acceleration followed
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// by abrupt asynchronous stops by each axes reaching their limit switch independently. The
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// asynchronous stops are handled by a system level axis lock mask, which prevents the stepper
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// algorithm from executing step pulses.
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// NOTE: Only the abort runtime command can interrupt this process.
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void limits_go_home(uint8_t cycle_mask, bool approach, bool invert_pin, float homing_rate)
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{
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if (sys.execute & EXEC_RESET) { return; }
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uint8_t limit_state;
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#ifndef LIMIT_SWITCHES_ACTIVE_HIGH
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invert_pin = !invert_pin;
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#endif
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// Determine travel distance to the furthest homing switch based on user max travel settings.
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float max_travel = settings.max_travel[X_AXIS];
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if (max_travel < settings.max_travel[Y_AXIS]) { max_travel = settings.max_travel[Y_AXIS]; }
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if (max_travel < settings.max_travel[Z_AXIS]) { max_travel = settings.max_travel[Z_AXIS]; }
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max_travel *= 1.25; // Ensure homing switches engaged by over-estimating max travel.
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if (approach) { max_travel = -max_travel; }
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// Set target location and rate for active axes.
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float target[N_AXIS];
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uint8_t n_active_axis = 0;
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uint8_t i;
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for (i=0; i<N_AXIS; i++) {
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if (bit_istrue(cycle_mask,bit(i))) {
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n_active_axis++;
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target[i] = max_travel;
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} else {
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target[i] = 0.0;
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}
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}
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if (bit_istrue(settings.homing_dir_mask,(1<<X_LIMIT_BIT))) { target[X_AXIS] = -target[X_AXIS]; }
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if (bit_istrue(settings.homing_dir_mask,(1<<Y_LIMIT_BIT))) { target[Y_AXIS] = -target[Y_AXIS]; }
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if (bit_istrue(settings.homing_dir_mask,(1<<Z_LIMIT_BIT))) { target[Z_AXIS] = -target[Z_AXIS]; }
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homing_rate *= sqrt(n_active_axis); // [sqrt(N_AXIS)] Adjust so individual axes all move at homing rate.
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// Setup homing axis locks based on cycle mask.
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uint8_t axislock = (STEPPING_MASK & ~STEP_MASK);
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if (bit_istrue(cycle_mask,bit(X_AXIS))) { axislock |= (1<<X_STEP_BIT); }
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if (bit_istrue(cycle_mask,bit(Y_AXIS))) { axislock |= (1<<Y_STEP_BIT); }
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if (bit_istrue(cycle_mask,bit(Z_AXIS))) { axislock |= (1<<Z_STEP_BIT); }
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sys.homing_axis_lock = axislock;
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// Perform homing cycle. Planner buffer should be empty, as required to initiate the homing cycle.
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plan_buffer_line(target, homing_rate, false); // Bypass mc_line(). Directly plan homing motion.
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st_prep_buffer(); // Prep first segment from newly planned block.
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st_wake_up(); // Initiate motion
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do {
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// Check limit state. Lock out cycle axes when they change.
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limit_state = LIMIT_PIN;
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if (invert_pin) { limit_state ^= LIMIT_MASK; }
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// if (axislock & (1<<X_STEP_BIT)) {
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if (limit_state & (1<<X_LIMIT_BIT)) { axislock &= ~(1<<X_STEP_BIT); }
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// }
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// if (axislock & (1<<Y_STEP_BIT)) {
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if (limit_state & (1<<Y_LIMIT_BIT)) { axislock &= ~(1<<Y_STEP_BIT); }
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// }
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// if (axislock & (1<<Z_STEP_BIT)) {
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if (limit_state & (1<<Z_LIMIT_BIT)) { axislock &= ~(1<<Z_STEP_BIT); }
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// }
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sys.homing_axis_lock = axislock;
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st_prep_buffer(); // Check and prep one segment. NOTE: Should take no longer than 200us.
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if (sys.execute & EXEC_RESET) { return; }
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} while (STEP_MASK & axislock);
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st_go_idle(); // Disable steppers. Axes motion should already be locked.
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plan_reset(); // Reset planner buffer. Ensure homing motion is cleared.
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st_reset(); // Reset step segment buffer. Ensure homing motion is cleared.
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delay_ms(settings.homing_debounce_delay); // Delay to allow transient dynamics to dissipate.
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}
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// Performs a soft limit check. Called from mc_line() only. Assumes the machine has been homed,
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// and the workspace volume is in all negative space.
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void limits_soft_check(float *target)
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{
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uint8_t idx;
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for (idx=0; idx<N_AXIS; idx++) {
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if (target[idx] > 0 || target[idx] < settings.max_travel[idx]) { // NOTE: max_travel is stored as negative
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// Force feed hold if cycle is active. All buffered blocks are guaranteed to be within
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// workspace volume so just come to a controlled stop so position is not lost. When complete
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// enter alarm mode.
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if (sys.state == STATE_CYCLE) {
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st_feed_hold();
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while (sys.state == STATE_HOLD) {
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protocol_execute_runtime();
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if (sys.abort) { return; }
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}
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}
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mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.
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sys.execute |= EXEC_CRIT_EVENT; // Indicate soft limit critical event
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protocol_execute_runtime(); // Execute to enter critical event loop and system abort
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return;
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}
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}
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}
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