grbl/limits.c

222 wiersze
9.2 KiB
C

/*
limits.c - code pertaining to limit-switches and performing the homing cycle
Part of Grbl
Copyright (c) 2012-2014 Sungeun K. Jeon
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 <util/delay.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
#include "stepper.h"
#include "settings.h"
#include "nuts_bolts.h"
#include "config.h"
#include "spindle_control.h"
#include "motion_control.h"
#include "planner.h"
#include "protocol.h"
#include "limits.h"
#include "report.h"
void limits_init()
{
LIMIT_DDR &= ~(LIMIT_MASK); // Set as input pins
if (bit_istrue(settings.flags,BITFLAG_INVERT_LIMIT_PINS)) {
LIMIT_PORT &= ~(LIMIT_MASK); // Normal low operation. Requires external pull-down.
} else {
LIMIT_PORT |= (LIMIT_MASK); // Enable internal pull-up resistors. Normal high operation.
}
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);
#endif
}
void limits_disable()
{
LIMIT_PCMSK &= ~LIMIT_MASK; // Disable specific pins of the Pin Change Interrupt
PCICR &= ~(1 << LIMIT_INT); // Disable Pin Change Interrupt
}
// 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 without a debouncing method.
// 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.
#ifdef ENABLE_SOFTWARE_DEBOUNCE
ISR(LIMIT_INT_vect) { if (!(WDTCSR & (1<<WDIE))) { WDTCSR |= (1<<WDIE); } }
ISR(WDT_vect)
{
WDTCSR &= ~(1<<WDIE);
// 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 (bit_isfalse(sys.execute,EXEC_ALARM)) {
#ifndef LIMIT_SWITCHES_ACTIVE_HIGH
if ((LIMIT_PIN & LIMIT_MASK) ^ LIMIT_MASK) {
#else
if (LIMIT_PIN & LIMIT_MASK) {
#endif
mc_reset(); // Initiate system kill.
sys.execute |= EXEC_CRIT_EVENT; // Indicate hard limit critical event
}
}
}
}
#else
ISR(LIMIT_INT_vect)
{
// 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 (bit_isfalse(sys.execute,EXEC_ALARM)) {
mc_reset(); // Initiate system kill.
sys.execute |= EXEC_CRIT_EVENT; // Indicate hard limit critical event
}
}
}
#endif
// Moves specified cycle axes all at homing rate, either approaching or disengaging the limit
// switches. Homing is a special motion case, where there is only an acceleration followed
// by abrupt asynchronous stops by each axes reaching their limit switch independently. The
// asynchronous stops are handled by a system level axis lock mask, which prevents the stepper
// algorithm from executing step pulses.
// NOTE: Only the abort runtime command can interrupt this process.
void limits_go_home(uint8_t cycle_mask, bool approach, float homing_rate)
{
if (sys.execute & EXEC_RESET) { return; }
uint8_t invert_pin;
if (bit_isfalse(settings.flags,BITFLAG_INVERT_LIMIT_PINS)) { invert_pin = approach; }
else { invert_pin = !approach; }
// Determine travel distance to the furthest homing switch based on user max travel settings.
// NOTE: settings.max_travel[] is stored as a negative value.
float max_travel = settings.max_travel[X_AXIS];
if (max_travel > settings.max_travel[Y_AXIS]) { max_travel = settings.max_travel[Y_AXIS]; }
if (max_travel > settings.max_travel[Z_AXIS]) { max_travel = settings.max_travel[Z_AXIS]; }
max_travel *= -1.25; // Ensure homing switches engaged by over-estimating max travel.
if (!approach) { max_travel = -max_travel; }
// Set target location and rate for active axes.
float target[N_AXIS];
uint8_t n_active_axis = 0;
uint8_t i;
for (i=0; i<N_AXIS; i++) {
if (bit_istrue(cycle_mask,bit(i))) {
n_active_axis++;
target[i] = max_travel;
} else {
target[i] = 0.0;
}
}
if (bit_istrue(settings.homing_dir_mask,(1<<X_LIMIT_BIT))) { target[X_AXIS] = -target[X_AXIS]; }
if (bit_istrue(settings.homing_dir_mask,(1<<Y_LIMIT_BIT))) { target[Y_AXIS] = -target[Y_AXIS]; }
if (bit_istrue(settings.homing_dir_mask,(1<<Z_LIMIT_BIT))) { target[Z_AXIS] = -target[Z_AXIS]; }
homing_rate *= sqrt(n_active_axis); // [sqrt(N_AXIS)] Adjust so individual axes all move at homing rate.
// Setup homing axis locks based on cycle mask.
uint8_t axislock = 0;
if (bit_istrue(cycle_mask,bit(X_AXIS))) { axislock |= (1<<X_STEP_BIT); }
if (bit_istrue(cycle_mask,bit(Y_AXIS))) { axislock |= (1<<Y_STEP_BIT); }
if (bit_istrue(cycle_mask,bit(Z_AXIS))) { axislock |= (1<<Z_STEP_BIT); }
sys.homing_axis_lock = axislock;
// Perform homing cycle. Planner buffer should be empty, as required to initiate the homing cycle.
uint8_t limit_state;
plan_buffer_line(target, homing_rate, false); // Bypass mc_line(). Directly plan homing motion.
st_prep_buffer(); // Prep first segment from newly planned block.
st_wake_up(); // Initiate motion
do {
// Check limit state. Lock out cycle axes when they change.
limit_state = LIMIT_PIN;
if (invert_pin) { limit_state ^= LIMIT_MASK; }
// if (axislock & (1<<X_STEP_BIT)) {
if (limit_state & (1<<X_LIMIT_BIT)) { axislock &= ~(1<<X_STEP_BIT); }
// }
// if (axislock & (1<<Y_STEP_BIT)) {
if (limit_state & (1<<Y_LIMIT_BIT)) { axislock &= ~(1<<Y_STEP_BIT); }
// }
// if (axislock & (1<<Z_STEP_BIT)) {
if (limit_state & (1<<Z_LIMIT_BIT)) { axislock &= ~(1<<Z_STEP_BIT); }
// }
sys.homing_axis_lock = axislock;
st_prep_buffer(); // Check and prep one segment. NOTE: Should take no longer than 200us.
if (sys.execute & EXEC_RESET) { return; }
} while (STEP_MASK & axislock);
st_go_idle(); // Disable steppers. Axes motion should already be locked.
plan_reset(); // Reset planner buffer. Ensure homing motion is cleared.
st_reset(); // Reset step segment buffer. Ensure homing motion is cleared.
delay_ms(settings.homing_debounce_delay); // Delay to allow transient dynamics to dissipate.
}
// Performs a soft limit check. Called from mc_line() only. Assumes the machine has been homed,
// and the workspace volume is in all negative space.
void limits_soft_check(float *target)
{
uint8_t idx;
for (idx=0; idx<N_AXIS; idx++) {
if (target[idx] > 0 || target[idx] < settings.max_travel[idx]) { // NOTE: max_travel is stored as negative
// 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) {
st_feed_hold();
while (sys.state == STATE_HOLD) {
protocol_execute_runtime();
if (sys.abort) { return; }
}
}
mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.
sys.execute |= EXEC_CRIT_EVENT; // Indicate soft limit critical event
protocol_execute_runtime(); // Execute to enter critical event loop and system abort
return;
}
}
}