kopia lustrzana https://github.com/Schildkroet/GRBL-Advanced
1510 wiersze
60 KiB
C
1510 wiersze
60 KiB
C
/*
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Stepper.c - stepper motor driver: executes motion plans using stepper motors
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Part of Grbl-Advanced
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Copyright (c) 2011-2016 Sungeun K. Jeon for Gnea Research LLC
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Copyright (c) 2009-2011 Simen Svale Skogsrud
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Copyright (c) 2017-2020 Patrick F.
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Grbl-Advanced 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-Advanced 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-Advanced. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <stdint.h>
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#include <string.h>
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#include <stdlib.h>
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#include "Config.h"
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#include "Planner.h"
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#include "Probe.h"
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#include "GCode.h"
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#include "SpindleControl.h"
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#include "System.h"
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#include "Settings.h"
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#include "util.h"
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#include "TIM.h"
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#include "Stepper.h"
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#include "GPIO.h"
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#include "System32.h"
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// Some useful constants.
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#define DT_SEGMENT (1.0/(ACCELERATION_TICKS_PER_SECOND*60.0)) // min/segment
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#define REQ_MM_INCREMENT_SCALAR 1.25
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#define RAMP_ACCEL 0
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#define RAMP_CRUISE 1
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#define RAMP_DECEL 2
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#define RAMP_DECEL_OVERRIDE 3
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#define PREP_FLAG_RECALCULATE BIT(0)
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#define PREP_FLAG_HOLD_PARTIAL_BLOCK BIT(1)
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#define PREP_FLAG_PARKING BIT(2)
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#define PREP_FLAG_DECEL_OVERRIDE BIT(3)
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// Define Adaptive Multi-Axis Step-Smoothing(AMASS) levels and cutoff frequencies. The highest level
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// frequency bin starts at 0Hz and ends at its cutoff frequency. The next lower level frequency bin
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// starts at the next higher cutoff frequency, and so on. The cutoff frequencies for each level must
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// be considered carefully against how much it over-drives the stepper ISR, the accuracy of the 16-bit
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// timer, and the CPU overhead. Level 0 (no AMASS, normal operation) frequency bin starts at the
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// Level 1 cutoff frequency and up to as fast as the CPU allows (over 30kHz in limited testing).
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// NOTE: AMASS cutoff frequency multiplied by ISR overdrive factor must not exceed maximum step frequency.
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// NOTE: Current settings are set to overdrive the ISR to no more than 16kHz, balancing CPU overhead
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// and timer accuracy. Do not alter these settings unless you know what you are doing.
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#define MAX_AMASS_LEVEL 5
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// AMASS_LEVEL0: Normal operation. No AMASS. No upper cutoff frequency. Starts at LEVEL1 cutoff frequency.
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#define AMASS_LEVEL1 (uint32_t)(F_TIMER_STEPPER / 8000) // Over-drives ISR (x2). Defined as F_TIMER_STEPPER/(Cutoff frequency in Hz)
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#define AMASS_LEVEL2 (uint32_t)(F_TIMER_STEPPER / 4000) // Over-drives ISR (x4)
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#define AMASS_LEVEL3 (uint32_t)(F_TIMER_STEPPER / 2000) // Over-drives ISR (x8)
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#define AMASS_LEVEL4 (uint32_t)(F_TIMER_STEPPER / 1000) // Over-drives ISR (x16)
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#define AMASS_LEVEL5 (uint32_t)(F_TIMER_STEPPER / 500) // Over-drives ISR (x32)
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#if MAX_AMASS_LEVEL <= 0
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error "AMASS must have 1 or more levels to operate correctly."
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#endif
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#ifdef MAX_STEP_RATE_HZ
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#define STEP_TIMER_MIN (uint16_t)(F_TIMER_STEPPER / MAX_STEP_RATE_HZ)
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#else
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#define STEP_TIMER_MIN (uint16_t)((F_TIMER_STEPPER / 120000))
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#pragma message("Max stepper rate: 120KHz")
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#endif
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#define G96_UPDATE_CNT 20
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// Stores the planner block Bresenham algorithm execution data for the segments in the segment
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// buffer. Normally, this buffer is partially in-use, but, for the worst case scenario, it will
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// never exceed the number of accessible stepper buffer segments (SEGMENT_BUFFER_SIZE-1).
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// NOTE: This data is copied from the prepped planner blocks so that the planner blocks may be
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// discarded when entirely consumed and completed by the segment buffer. Also, AMASS alters this
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// data for its own use.
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typedef struct
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{
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uint32_t steps[N_AXIS];
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uint32_t step_event_count;
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uint8_t direction_bits;
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uint8_t is_pwm_rate_adjusted; // Tracks motions that require constant laser power/rate
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} Stepper_Block_t;
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// Primary stepper segment ring buffer. Contains small, short line segments for the stepper
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// algorithm to execute, which are "checked-out" incrementally from the first block in the
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// planner buffer. Once "checked-out", the steps in the segments buffer cannot be modified by
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// the planner, where the remaining planner block steps still can.
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typedef struct
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{
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uint16_t n_step; // Number of step events to be executed for this segment
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uint16_t cycles_per_tick; // Step distance traveled per ISR tick, aka step rate.
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uint8_t st_block_index; // Stepper block data index. Uses this information to execute this segment.
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uint8_t amass_level; // Indicates AMASS level for the ISR to execute this segment
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uint8_t spindle_pwm;
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uint8_t backlash_motion;
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} Stepper_Segment_t;
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// Stepper ISR data struct. Contains the running data for the main stepper ISR.
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typedef struct
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{
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// Used by the bresenham line algorithm
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// Counter variables for the bresenham line tracer
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uint32_t counter_x, counter_y, counter_z, counter_a, counter_b;
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uint8_t execute_step; // Flags step execution for each interrupt.
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uint8_t step_pulse_time; // Step pulse reset time after step rise
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uint8_t step_outbits; // The next stepping-bits to be output
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uint8_t dir_outbits;
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uint32_t steps[N_AXIS];
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uint16_t step_count; // Steps remaining in line segment motion
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uint8_t exec_block_index; // Tracks the current st_block index. Change indicates new block.
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Stepper_Block_t *exec_block; // Pointer to the block data for the segment being executed
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Stepper_Segment_t *exec_segment; // Pointer to the segment being executed
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} Stepper_t;
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// Segment preparation data struct. Contains all the necessary information to compute new segments
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// based on the current executing planner block.
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typedef struct
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{
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uint8_t st_block_index; // Index of stepper common data block being prepped
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uint8_t recalculate_flag;
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float dt_remainder;
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float steps_remaining;
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float step_per_mm;
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float req_mm_increment;
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#ifdef PARKING_ENABLE
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uint8_t last_st_block_index;
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float last_steps_remaining;
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float last_step_per_mm;
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float last_dt_remainder;
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#endif
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uint8_t ramp_type; // Current segment ramp state
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float mm_complete; // End of velocity profile from end of current planner block in (mm).
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// NOTE: This value must coincide with a step(no mantissa) when converted.
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float current_speed; // Current speed at the end of the segment buffer (mm/min)
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float maximum_speed; // Maximum speed of executing block. Not always nominal speed. (mm/min)
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float exit_speed; // Exit speed of executing block (mm/min)
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float accelerate_until; // Acceleration ramp end measured from end of block (mm)
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float decelerate_after; // Deceleration ramp start measured from end of block (mm)
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float inv_rate; // Used by PWM laser mode to speed up segment calculations.
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uint8_t current_spindle_pwm;
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} Stepper_PrepData_t;
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static Stepper_Block_t st_block_buffer[SEGMENT_BUFFER_SIZE-1];
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static Stepper_Segment_t segment_buffer[SEGMENT_BUFFER_SIZE];
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static Stepper_t st;
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// Step segment ring buffer indices
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static volatile uint8_t segment_buffer_tail;
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static uint8_t segment_buffer_head;
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static uint8_t segment_next_head;
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// Step and direction port invert masks.
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static uint8_t step_port_invert_mask;
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static uint8_t dir_port_invert_mask;
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// Pointers for the step segment being prepped from the planner buffer. Accessed only by the
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// main program. Pointers may be planning segments or planner blocks ahead of what being executed.
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static Planner_Block_t *pl_block; // Pointer to the planner block being prepped
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static Stepper_Block_t *st_prep_block; // Pointer to the stepper block data being prepped
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static Stepper_PrepData_t prep;
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static float tim_ovr = 0;
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static uint8_t update_g96 = G96_UPDATE_CNT;
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float current_backlash[N_AXIS] = {};
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/* BLOCK VELOCITY PROFILE DEFINITION
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__________________________
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/| |\ _________________ ^
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/ | | \ /| |\ |
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/ | | \ / | | \ s
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/ | | | | | \ p
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/ | | | | | \ e
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+-----+------------------------+---+--+---------------+----+ e
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| BLOCK 1 ^ BLOCK 2 | d
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time -----> EXAMPLE: Block 2 entry speed is at max junction velocity
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The planner block buffer is planned assuming constant acceleration velocity profiles and are
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continuously joined at block junctions as shown above. However, the planner only actively computes
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the block entry speeds for an optimal velocity plan, but does not compute the block internal
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velocity profiles. These velocity profiles are computed ad-hoc as they are executed by the
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stepper algorithm and consists of only 7 possible types of profiles: cruise-only, cruise-
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deceleration, acceleration-cruise, acceleration-only, deceleration-only, full-trapezoid, and
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triangle(no cruise).
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maximum_speed (< nominal_speed) -> +
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+--------+ <- maximum_speed (= nominal_speed) /|\
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/ \ / | \
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current_speed -> + \ / | + <- exit_speed
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| + <- exit_speed / | |
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+-------------+ current_speed -> +----+--+
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time --> ^ ^ ^ ^
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decelerate_after(in mm) decelerate_after(in mm)
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^ ^ ^ ^
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accelerate_until(in mm) accelerate_until(in mm)
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The step segment buffer computes the executing block velocity profile and tracks the critical
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parameters for the stepper algorithm to accurately trace the profile. These critical parameters
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are shown and defined in the above illustration.
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*/
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// Initialize and start the stepper motor subsystem
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void Stepper_Init(void)
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{
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// Configure step and direction interface pins
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GPIO_InitGPIO(GPIO_STEPPER);
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// Init TIM9
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TIM9_Init();
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if(BIT_IS_TRUE(settings.flags, BITFLAG_HOMING_ENABLE))
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{
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Stepper_Disable(1);
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}
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tim_ovr = 0;
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update_g96 = G96_UPDATE_CNT;
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for(int i = 0; i < N_AXIS; i++)
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{
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current_backlash[i] = 0.0;
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}
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}
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// Stepper state initialization. Cycle should only start if the st.cycle_start flag is
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// enabled. Startup init and limits call this function but shouldn't start the cycle.
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void Stepper_WakeUp(void)
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{
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// Enable stepper drivers.
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if(BIT_IS_TRUE(settings.flags, BITFLAG_INVERT_ST_ENABLE))
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{
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GPIO_SetBits(GPIO_ENABLE_PORT, GPIO_ENABLE_PIN);
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}
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else
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{
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GPIO_ResetBits(GPIO_ENABLE_PORT, GPIO_ENABLE_PIN);
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}
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// Give steppers some time to wake up
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Delay_ms(10);
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// Initialize stepper output bits to ensure first ISR call does not step.
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//st.step_outbits = step_port_invert_mask;
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st.step_outbits = 0;
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// Enable Stepper Driver Interrupt
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TIM_Cmd(TIM9, ENABLE);
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}
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// Stepper shutdown
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void Stepper_Disable(uint8_t ovr_disable)
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{
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// Disable Stepper Driver Interrupt.
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TIM_Cmd(TIM9, DISABLE);
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Delay_us(1);
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// Reset stepper pins
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Stepper_PortResetISR();
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// Set stepper driver idle state, disabled or enabled, depending on settings and circumstances.
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bool pin_state = false; // Keep enabled.
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if(((settings.stepper_idle_lock_time != 0xFF) || sys_rt_exec_alarm || sys.state == STATE_SLEEP) && sys.state != STATE_HOMING)
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{
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// Force stepper dwell to lock axes for a defined amount of time to ensure the axes come to a complete
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// stop and not drift from residual inertial forces at the end of the last movement.
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Delay_ms(settings.stepper_idle_lock_time);
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pin_state = true; // Override. Disable steppers.
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}
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if(ovr_disable)
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{
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// Disable
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pin_state = true;
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}
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if(BIT_IS_TRUE(settings.flags, BITFLAG_INVERT_ST_ENABLE))
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{
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pin_state = !pin_state;
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} // Apply pin invert.
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if(pin_state)
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{
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GPIO_SetBits(GPIO_ENABLE_PORT, GPIO_ENABLE_PIN);
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}
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else
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{
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GPIO_ResetBits(GPIO_ENABLE_PORT, GPIO_ENABLE_PIN);
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}
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}
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void Stepper_Ovr(float ovr)
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{
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tim_ovr = ovr;
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}
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/* "The Stepper Driver Interrupt" - This timer interrupt is the workhorse of Grbl. Grbl employs
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the venerable Bresenham line algorithm to manage and exactly synchronize multi-axis moves.
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Unlike the popular DDA algorithm, the Bresenham algorithm is not susceptible to numerical
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round-off errors and only requires fast integer counters, meaning low computational overhead
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and maximizing the Arduino's capabilities. However, the downside of the Bresenham algorithm
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is, for certain multi-axis motions, the non-dominant axes may suffer from un-smooth step
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pulse trains, or aliasing, which can lead to strange audible noises or shaking. This is
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particularly noticeable or may cause motion issues at low step frequencies (0-5kHz), but
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is usually not a physical problem at higher frequencies, although audible.
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To improve Bresenham multi-axis performance, Grbl uses what we call an Adaptive Multi-Axis
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Step Smoothing (AMASS) algorithm, which does what the name implies. At lower step frequencies,
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AMASS artificially increases the Bresenham resolution without effecting the algorithm's
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innate exactness. AMASS adapts its resolution levels automatically depending on the step
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frequency to be executed, meaning that for even lower step frequencies the step smoothing
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level increases. Algorithmically, AMASS is acheived by a simple bit-shifting of the Bresenham
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step count for each AMASS level. For example, for a Level 1 step smoothing, we bit shift
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the Bresenham step event count, effectively multiplying it by 2, while the axis step counts
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remain the same, and then double the stepper ISR frequency. In effect, we are allowing the
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non-dominant Bresenham axes step in the intermediate ISR tick, while the dominant axis is
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stepping every two ISR ticks, rather than every ISR tick in the traditional sense. At AMASS
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Level 2, we simply bit-shift again, so the non-dominant Bresenham axes can step within any
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of the four ISR ticks, the dominant axis steps every four ISR ticks, and quadruple the
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stepper ISR frequency. And so on. This, in effect, virtually eliminates multi-axis aliasing
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issues with the Bresenham algorithm and does not significantly alter Grbl's performance, but
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in fact, more efficiently utilizes unused CPU cycles overall throughout all configurations.
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AMASS retains the Bresenham algorithm exactness by requiring that it always executes a full
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Bresenham step, regardless of AMASS Level. Meaning that for an AMASS Level 2, all four
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intermediate steps must be completed such that baseline Bresenham (Level 0) count is always
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retained. Similarly, AMASS Level 3 means all eight intermediate steps must be executed.
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Although the AMASS Levels are in reality arbitrary, where the baseline Bresenham counts can
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be multiplied by any integer value, multiplication by powers of two are simply used to ease
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CPU overhead with bitshift integer operations.
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This interrupt is simple and dumb by design. All the computational heavy-lifting, as in
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determining accelerations, is performed elsewhere. This interrupt pops pre-computed segments,
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defined as constant velocity over n number of steps, from the step segment buffer and then
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executes them by pulsing the stepper pins appropriately via the Bresenham algorithm. This
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ISR is supported by The Stepper Port Reset Interrupt which it uses to reset the stepper port
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after each pulse. The bresenham line tracer algorithm controls all stepper outputs
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simultaneously with these two interrupts.
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NOTE: This interrupt must be as efficient as possible and complete before the next ISR tick,
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which for Grbl must be less than 33.3usec (@30kHz ISR rate). Oscilloscope measured time in
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ISR is 5usec typical and 25usec maximum, well below requirement.
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NOTE: This ISR expects at least one step to be executed per segment.
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*/
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void Stepper_MainISR(void)
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{
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if(st.step_outbits & (1<<X_STEP_BIT))
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{
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if(step_port_invert_mask & (1<<X_STEP_BIT))
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{
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// Low pulse
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GPIO_ResetBits(GPIO_STEP_X_PORT, GPIO_STEP_X_PIN);
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}
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else
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{
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// High pulse
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GPIO_SetBits(GPIO_STEP_X_PORT, GPIO_STEP_X_PIN);
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}
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}
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if (BIT_IS_FALSE(settings.flags_ext, BITFLAG_LATHE_MODE))
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{
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if (st.step_outbits & (1 << Y_STEP_BIT))
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{
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if (step_port_invert_mask & (1 << Y_STEP_BIT))
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{
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// Low pulse
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GPIO_ResetBits(GPIO_STEP_Y_PORT, GPIO_STEP_Y_PIN);
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}
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else
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{
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// High pulse
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GPIO_SetBits(GPIO_STEP_Y_PORT, GPIO_STEP_Y_PIN);
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}
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}
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}
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if(st.step_outbits & (1<<Z_STEP_BIT))
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{
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if(step_port_invert_mask & (1<<Z_STEP_BIT))
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{
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// Low pulse
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GPIO_ResetBits(GPIO_STEP_Z_PORT, GPIO_STEP_Z_PIN);
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}
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else
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{
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// High pulse
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GPIO_SetBits(GPIO_STEP_Z_PORT, GPIO_STEP_Z_PIN);
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}
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}
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if(st.step_outbits & (1<<A_STEP_BIT))
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{
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if(step_port_invert_mask & (1<<A_STEP_BIT))
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{
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// Low pulse
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GPIO_ResetBits(GPIO_STEP_A_PORT, GPIO_STEP_A_PIN);
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}
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else
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{
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// High pulse
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GPIO_SetBits(GPIO_STEP_A_PORT, GPIO_STEP_A_PIN);
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}
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}
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if(st.step_outbits & (1<<B_STEP_BIT))
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{
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if(step_port_invert_mask & (1<<B_STEP_BIT))
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{
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// Low pulse
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//GPIO_ResetBits(GPIO_STEP_B_PORT, GPIO_STEP_B_PIN);
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}
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else
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{
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// High pulse
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//GPIO_SetBits(GPIO_STEP_B_PORT, GPIO_STEP_B_PIN);
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}
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}
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// If there is no step segment, attempt to pop one from the stepper buffer
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if(st.exec_segment == 0)
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{
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// Anything in the buffer? If so, load and initialize next step segment.
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if(segment_buffer_head != segment_buffer_tail)
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{
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// Initialize new step segment and load number of steps to execute
|
|
st.exec_segment = &segment_buffer[segment_buffer_tail];
|
|
|
|
// Initialize step segment timing per step and load number of steps to execute.
|
|
// Limit ISR frequency
|
|
if(st.exec_segment->cycles_per_tick < STEP_TIMER_MIN)
|
|
{
|
|
st.exec_segment->cycles_per_tick = STEP_TIMER_MIN;
|
|
}
|
|
|
|
int32_t new_cycles_per_tick = st.exec_segment->cycles_per_tick;
|
|
if(sys.sync_move == 1)
|
|
{
|
|
new_cycles_per_tick = st.exec_segment->cycles_per_tick * tim_ovr;
|
|
new_cycles_per_tick = st.exec_segment->cycles_per_tick + new_cycles_per_tick;
|
|
if (new_cycles_per_tick > 0xFFFF)
|
|
{
|
|
new_cycles_per_tick = 0xFFFF;
|
|
}
|
|
if(new_cycles_per_tick < STEP_TIMER_MIN-50)
|
|
{
|
|
new_cycles_per_tick = STEP_TIMER_MIN-50;
|
|
}
|
|
}
|
|
|
|
// Update TIM9 register for next interrupt
|
|
//TIM9->ARR = st.exec_segment->cycles_per_tick;
|
|
//TIM9->CCR1 = (uint16_t)(st.exec_segment->cycles_per_tick * 0.6);
|
|
TIM9->ARR = (uint16_t)new_cycles_per_tick;
|
|
TIM9->CCR1 = (uint16_t)(new_cycles_per_tick * 0.6);
|
|
st.step_count = st.exec_segment->n_step; // NOTE: Can sometimes be zero when moving slow.
|
|
|
|
// If the new segment starts a new planner block, initialize stepper variables and counters.
|
|
// NOTE: When the segment data index changes, this indicates a new planner block.
|
|
if(st.exec_block_index != st.exec_segment->st_block_index)
|
|
{
|
|
st.exec_block_index = st.exec_segment->st_block_index;
|
|
st.exec_block = &st_block_buffer[st.exec_block_index];
|
|
|
|
// Initialize Bresenham line and distance counters
|
|
st.counter_x = st.counter_y = st.counter_z = st.counter_a = st.counter_b = (st.exec_block->step_event_count >> 1);
|
|
}
|
|
|
|
st.dir_outbits = st.exec_block->direction_bits ^ dir_port_invert_mask;
|
|
|
|
// Set the direction pins directly here to make sure that the signal is valid when stepping the steppers
|
|
// Some driver e.g. require a setup time of a few us.
|
|
if(st.dir_outbits & (1<<X_DIRECTION_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_DIR_X_PORT, GPIO_DIR_X_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_DIR_X_PORT, GPIO_DIR_X_PIN);
|
|
}
|
|
if (BIT_IS_FALSE(settings.flags_ext, BITFLAG_LATHE_MODE))
|
|
{
|
|
if (st.dir_outbits & (1 << Y_DIRECTION_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_DIR_Y_PORT, GPIO_DIR_Y_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_DIR_Y_PORT, GPIO_DIR_Y_PIN);
|
|
}
|
|
}
|
|
if(st.dir_outbits & (1<<Z_DIRECTION_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_DIR_Z_PORT, GPIO_DIR_Z_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_DIR_Z_PORT, GPIO_DIR_Z_PIN);
|
|
}
|
|
if(st.dir_outbits & (1<<A_DIRECTION_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_DIR_A_PORT, GPIO_DIR_A_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_DIR_A_PORT, GPIO_DIR_A_PIN);
|
|
}
|
|
if(st.dir_outbits & (1<<B_DIRECTION_BIT))
|
|
{
|
|
//GPIO_SetBits(GPIO_DIR_B_PORT, GPIO_DIR_B_PIN);
|
|
}
|
|
else
|
|
{
|
|
//GPIO_ResetBits(GPIO_DIR_B_PORT, GPIO_DIR_B_PIN);
|
|
}
|
|
|
|
// With AMASS enabled, adjust Bresenham axis increment counters according to AMASS level.
|
|
st.steps[X_AXIS] = st.exec_block->steps[X_AXIS] >> st.exec_segment->amass_level;
|
|
st.steps[Y_AXIS] = st.exec_block->steps[Y_AXIS] >> st.exec_segment->amass_level;
|
|
st.steps[Z_AXIS] = st.exec_block->steps[Z_AXIS] >> st.exec_segment->amass_level;
|
|
st.steps[A_AXIS] = st.exec_block->steps[A_AXIS] >> st.exec_segment->amass_level;
|
|
st.steps[B_AXIS] = st.exec_block->steps[B_AXIS] >> st.exec_segment->amass_level;
|
|
|
|
if(gc_state.modal.spindle_mode == SPINDLE_RPM_MODE)
|
|
{
|
|
// Set real-time spindle output as segment is loaded, just prior to the first step.
|
|
Spindle_SetSpeed(st.exec_segment->spindle_pwm);
|
|
}
|
|
else if(st.exec_segment->spindle_pwm != SPINDLE_PWM_OFF_VALUE)
|
|
{
|
|
if(--update_g96 == 0)
|
|
{
|
|
sys.x_pos = (sys_position[X_AXIS] / settings.steps_per_mm[X_AXIS]) - (gc_state.coord_system[X_AXIS] + gc_state.coord_offset[X_AXIS] + gc_state.tool_length_offset_dynamic[X_AXIS] + gc_state.tool_length_offset[X_AXIS]);
|
|
Spindle_SetSurfaceSpeed(sys.x_pos);
|
|
update_g96 = G96_UPDATE_CNT;
|
|
}
|
|
}
|
|
|
|
}
|
|
else
|
|
{
|
|
// Segment buffer empty. Shutdown.
|
|
Stepper_Disable(0);
|
|
|
|
// Ensure pwm is set properly upon completion of rate-controlled motion.
|
|
if(st.exec_block->is_pwm_rate_adjusted)
|
|
{
|
|
Spindle_SetSpeed(SPINDLE_PWM_OFF_VALUE);
|
|
}
|
|
System_SetExecStateFlag(EXEC_CYCLE_STOP); // Flag main program for cycle end
|
|
|
|
return; // Nothing to do but exit.
|
|
}
|
|
}
|
|
|
|
// Check probing state.
|
|
if(sys_probe_state == PROBE_ACTIVE)
|
|
{
|
|
Probe_StateMonitor();
|
|
}
|
|
|
|
// Reset step out bits.
|
|
st.step_outbits = 0;
|
|
|
|
// Execute step displacement profile by Bresenham line algorithm
|
|
st.counter_x += st.steps[X_AXIS];
|
|
|
|
if(st.counter_x > st.exec_block->step_event_count)
|
|
{
|
|
st.step_outbits |= (1<<X_STEP_BIT);
|
|
st.counter_x -= st.exec_block->step_event_count;
|
|
|
|
if (st.exec_block->direction_bits & (1 << X_DIRECTION_BIT))
|
|
{
|
|
sys_position[X_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
sys_position[X_AXIS]++;
|
|
}
|
|
|
|
if (fabsf(current_backlash[X_AXIS]) > 0.5)
|
|
{
|
|
if (current_backlash[X_AXIS] > 0.0)
|
|
{
|
|
current_backlash[X_AXIS] -= 1.0;
|
|
sys_position[X_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
current_backlash[X_AXIS] += 1.0;
|
|
sys_position[X_AXIS]++;
|
|
}
|
|
}
|
|
}
|
|
|
|
st.counter_y += st.steps[Y_AXIS];
|
|
|
|
if (st.counter_y > st.exec_block->step_event_count)
|
|
{
|
|
st.step_outbits |= (1 << Y_STEP_BIT);
|
|
st.counter_y -= st.exec_block->step_event_count;
|
|
|
|
if (st.exec_block->direction_bits & (1 << Y_DIRECTION_BIT))
|
|
{
|
|
sys_position[Y_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
sys_position[Y_AXIS]++;
|
|
}
|
|
|
|
if (fabsf(current_backlash[Y_AXIS]) > 0.5)
|
|
{
|
|
if (current_backlash[Y_AXIS] > 0.0)
|
|
{
|
|
current_backlash[Y_AXIS] -= 1.0;
|
|
sys_position[Y_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
current_backlash[Y_AXIS] += 1.0;
|
|
sys_position[Y_AXIS]++;
|
|
}
|
|
}
|
|
}
|
|
|
|
st.counter_z += st.steps[Z_AXIS];
|
|
|
|
if (st.counter_z > st.exec_block->step_event_count)
|
|
{
|
|
st.step_outbits |= (1 << Z_STEP_BIT);
|
|
st.counter_z -= st.exec_block->step_event_count;
|
|
|
|
if (st.exec_block->direction_bits & (1 << Z_DIRECTION_BIT))
|
|
{
|
|
sys_position[Z_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
sys_position[Z_AXIS]++;
|
|
}
|
|
|
|
if (fabsf(current_backlash[Z_AXIS]) > 0.5)
|
|
{
|
|
if (current_backlash[Z_AXIS] > 0.0)
|
|
{
|
|
current_backlash[Z_AXIS] -= 1.0;
|
|
sys_position[Z_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
current_backlash[Z_AXIS] += 1.0;
|
|
sys_position[Z_AXIS]++;
|
|
}
|
|
}
|
|
}
|
|
|
|
st.counter_a += st.steps[A_AXIS];
|
|
|
|
if(st.counter_a > st.exec_block->step_event_count)
|
|
{
|
|
st.step_outbits |= (1<<A_STEP_BIT);
|
|
st.counter_a -= st.exec_block->step_event_count;
|
|
|
|
//if(st.exec_segment->backlash_motion == 0)
|
|
{
|
|
if(st.exec_block->direction_bits & (1<<A_DIRECTION_BIT))
|
|
{
|
|
sys_position[A_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
sys_position[A_AXIS]++;
|
|
}
|
|
}
|
|
}
|
|
|
|
st.counter_b += st.steps[B_AXIS];
|
|
|
|
if(st.counter_b > st.exec_block->step_event_count)
|
|
{
|
|
st.step_outbits |= (1<<B_STEP_BIT);
|
|
st.counter_b -= st.exec_block->step_event_count;
|
|
|
|
//if(st.exec_segment->backlash_motion == 0)
|
|
{
|
|
if(st.exec_block->direction_bits & (1<<B_DIRECTION_BIT))
|
|
{
|
|
sys_position[B_AXIS]--;
|
|
}
|
|
else
|
|
{
|
|
sys_position[B_AXIS]++;
|
|
}
|
|
}
|
|
}
|
|
|
|
// During a homing cycle, lock out and prevent desired axes from moving.
|
|
if(sys.state == STATE_HOMING)
|
|
{
|
|
st.step_outbits &= sys.homing_axis_lock;
|
|
}
|
|
|
|
st.step_count--; // Decrement step events count
|
|
if(st.step_count == 0)
|
|
{
|
|
// Segment is complete. Discard current segment and advance segment indexing.
|
|
st.exec_segment = 0;
|
|
|
|
if(++segment_buffer_tail == SEGMENT_BUFFER_SIZE)
|
|
{
|
|
segment_buffer_tail = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* The Stepper Port Reset Interrupt: Timer9 OVF interrupt handles the falling edge of the step
|
|
pulse.
|
|
NOTE: Interrupt collisions between the serial and stepper interrupts can cause delays by
|
|
a few microseconds, if they execute right before one another. Not a big deal, but can
|
|
cause issues at high step rates if another high frequency asynchronous interrupt is
|
|
added to Grbl.
|
|
*/
|
|
void Stepper_PortResetISR(void)
|
|
{
|
|
// Reset stepping pins (leave the direction pins)
|
|
|
|
// X
|
|
if(step_port_invert_mask & (1<<X_STEP_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_STEP_X_PORT, GPIO_STEP_X_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_STEP_X_PORT, GPIO_STEP_X_PIN);
|
|
}
|
|
|
|
// Y
|
|
if (BIT_IS_FALSE(settings.flags_ext, BITFLAG_LATHE_MODE))
|
|
{
|
|
if (step_port_invert_mask & (1 << Y_STEP_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_STEP_Y_PORT, GPIO_STEP_Y_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_STEP_Y_PORT, GPIO_STEP_Y_PIN);
|
|
}
|
|
}
|
|
|
|
// Z
|
|
if(step_port_invert_mask & (1<<Z_STEP_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_STEP_Z_PORT, GPIO_STEP_Z_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_STEP_Z_PORT, GPIO_STEP_Z_PIN);
|
|
}
|
|
|
|
// A
|
|
if(step_port_invert_mask & (1<<A_STEP_BIT))
|
|
{
|
|
GPIO_SetBits(GPIO_STEP_A_PORT, GPIO_STEP_A_PIN);
|
|
}
|
|
else
|
|
{
|
|
GPIO_ResetBits(GPIO_STEP_A_PORT, GPIO_STEP_A_PIN);
|
|
}
|
|
|
|
// B
|
|
if(step_port_invert_mask & (1<<B_STEP_BIT))
|
|
{
|
|
//GPIO_SetBits(GPIO_STEP_B_PORT, GPIO_STEP_B_PIN);
|
|
}
|
|
else
|
|
{
|
|
//GPIO_ResetBits(GPIO_STEP_B_PORT, GPIO_STEP_B_PIN);
|
|
}
|
|
}
|
|
|
|
|
|
// Generates the step and direction port invert masks used in the Stepper Interrupt Driver.
|
|
void Stepper_GenerateStepDirInvertMasks(void)
|
|
{
|
|
uint8_t idx;
|
|
|
|
step_port_invert_mask = 0;
|
|
dir_port_invert_mask = 0;
|
|
|
|
for(idx = 0; idx < N_AXIS; idx++)
|
|
{
|
|
if(BIT_IS_TRUE(settings.step_invert_mask, BIT(idx)))
|
|
{
|
|
step_port_invert_mask |= Settings_GetStepPinMask(idx);
|
|
}
|
|
|
|
if(BIT_IS_TRUE(settings.dir_invert_mask, BIT(idx)))
|
|
{
|
|
dir_port_invert_mask |= Settings_GetDirectionPinMask(idx);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
// Reset and clear stepper subsystem variables
|
|
void Stepper_Reset(void)
|
|
{
|
|
// Initialize stepper driver idle state.
|
|
Stepper_Disable(0);
|
|
|
|
// Initialize stepper algorithm variables.
|
|
memset(&prep, 0, sizeof(Stepper_PrepData_t));
|
|
memset(&st, 0, sizeof(Stepper_t));
|
|
|
|
st.exec_segment = 0;
|
|
pl_block = 0; // Planner block pointer used by segment buffer
|
|
segment_buffer_tail = 0;
|
|
segment_buffer_head = 0; // empty = tail
|
|
segment_next_head = 1;
|
|
|
|
Stepper_GenerateStepDirInvertMasks();
|
|
st.dir_outbits = dir_port_invert_mask; // Initialize direction bits to default.
|
|
|
|
// Initialize step and direction port pins.
|
|
// Reset Step Pins
|
|
Stepper_PortResetISR();
|
|
|
|
// Reset Direction Pins
|
|
// ToDo: Use invert mask?
|
|
GPIO_ResetBits(GPIO_DIR_X_PORT, GPIO_DIR_X_PIN);
|
|
if (BIT_IS_FALSE(settings.flags_ext, BITFLAG_LATHE_MODE))
|
|
{
|
|
GPIO_ResetBits(GPIO_DIR_Y_PORT, GPIO_DIR_Y_PIN);
|
|
}
|
|
GPIO_ResetBits(GPIO_DIR_Z_PORT, GPIO_DIR_Z_PIN);
|
|
GPIO_ResetBits(GPIO_DIR_A_PORT, GPIO_DIR_A_PIN);
|
|
//GPIO_ResetBits(GPIO_DIR_B_PORT, GPIO_DIR_B_PIN);
|
|
}
|
|
|
|
|
|
// Called by planner_recalculate() when the executing block is updated by the new plan.
|
|
void Stepper_UpdatePlannerBlockParams(void)
|
|
{
|
|
if(pl_block != 0) // Ignore if at start of a new block.
|
|
{
|
|
prep.recalculate_flag |= PREP_FLAG_RECALCULATE;
|
|
pl_block->entry_speed_sqr = prep.current_speed*prep.current_speed; // Update entry speed.
|
|
pl_block = 0; // Flag st_prep_segment() to load and check active velocity profile.
|
|
}
|
|
}
|
|
|
|
|
|
// Increments the step segment buffer block data ring buffer.
|
|
static uint8_t Stepper_NextBlockIndex(uint8_t block_index)
|
|
{
|
|
block_index++;
|
|
|
|
if(block_index == (SEGMENT_BUFFER_SIZE-1))
|
|
{
|
|
return(0);
|
|
}
|
|
|
|
return block_index;
|
|
}
|
|
|
|
|
|
#ifdef PARKING_ENABLE
|
|
// Changes the run state of the step segment buffer to execute the special parking motion.
|
|
void Stepper_ParkingSetupBuffer()
|
|
{
|
|
// Store step execution data of partially completed block, if necessary.
|
|
if(prep.recalculate_flag & PREP_FLAG_HOLD_PARTIAL_BLOCK)
|
|
{
|
|
prep.last_st_block_index = prep.st_block_index;
|
|
prep.last_steps_remaining = prep.steps_remaining;
|
|
prep.last_dt_remainder = prep.dt_remainder;
|
|
prep.last_step_per_mm = prep.step_per_mm;
|
|
}
|
|
// Set flags to execute a parking motion
|
|
prep.recalculate_flag |= PREP_FLAG_PARKING;
|
|
prep.recalculate_flag &= ~(PREP_FLAG_RECALCULATE);
|
|
pl_block = 0; // Always reset parking motion to reload new block.
|
|
}
|
|
|
|
|
|
// Restores the step segment buffer to the normal run state after a parking motion.
|
|
void Stepper_ParkingRestoreBuffer()
|
|
{
|
|
// Restore step execution data and flags of partially completed block, if necessary.
|
|
if(prep.recalculate_flag & PREP_FLAG_HOLD_PARTIAL_BLOCK)
|
|
{
|
|
st_prep_block = &st_block_buffer[prep.last_st_block_index];
|
|
prep.st_block_index = prep.last_st_block_index;
|
|
prep.steps_remaining = prep.last_steps_remaining;
|
|
prep.dt_remainder = prep.last_dt_remainder;
|
|
prep.step_per_mm = prep.last_step_per_mm;
|
|
prep.recalculate_flag = (PREP_FLAG_HOLD_PARTIAL_BLOCK | PREP_FLAG_RECALCULATE);
|
|
prep.req_mm_increment = REQ_MM_INCREMENT_SCALAR/prep.step_per_mm; // Recompute this value.
|
|
}
|
|
else
|
|
{
|
|
prep.recalculate_flag = false;
|
|
}
|
|
|
|
pl_block = NULL; // Set to reload next block.
|
|
}
|
|
#endif
|
|
|
|
|
|
/* Prepares step segment buffer. Continuously called from main program.
|
|
|
|
The segment buffer is an intermediary buffer interface between the execution of steps
|
|
by the stepper algorithm and the velocity profiles generated by the planner. The stepper
|
|
algorithm only executes steps within the segment buffer and is filled by the main program
|
|
when steps are "checked-out" from the first block in the planner buffer. This keeps the
|
|
step execution and planning optimization processes atomic and protected from each other.
|
|
The number of steps "checked-out" from the planner buffer and the number of segments in
|
|
the segment buffer is sized and computed such that no operation in the main program takes
|
|
longer than the time it takes the stepper algorithm to empty it before refilling it.
|
|
Currently, the segment buffer conservatively holds roughly up to 40-50 msec of steps.
|
|
NOTE: Computation units are in steps, millimeters, and minutes.
|
|
*/
|
|
void Stepper_PrepareBuffer(void)
|
|
{
|
|
// Block step prep buffer, while in a suspend state and there is no suspend motion to execute.
|
|
if(BIT_IS_TRUE(sys.step_control,STEP_CONTROL_END_MOTION))
|
|
{
|
|
return;
|
|
}
|
|
|
|
while(segment_buffer_tail != segment_next_head) // Check if we need to fill the buffer.
|
|
{
|
|
// Determine if we need to load a new planner block or if the block needs to be recomputed.
|
|
if(pl_block == 0)
|
|
{
|
|
// Query planner for a queued block
|
|
if(sys.step_control & STEP_CONTROL_EXECUTE_SYS_MOTION)
|
|
{
|
|
pl_block = Planner_GetSystemMotionBlock();
|
|
}
|
|
else
|
|
{
|
|
pl_block = Planner_GetCurrentBlock();
|
|
}
|
|
|
|
if(pl_block == 0)
|
|
{
|
|
// No planner blocks. Exit.
|
|
return;
|
|
}
|
|
|
|
// Check if we need to only recompute the velocity profile or load a new block.
|
|
if(prep.recalculate_flag & PREP_FLAG_RECALCULATE)
|
|
{
|
|
#ifdef PARKING_ENABLE
|
|
if(prep.recalculate_flag & PREP_FLAG_PARKING)
|
|
{
|
|
prep.recalculate_flag &= ~(PREP_FLAG_RECALCULATE);
|
|
}
|
|
else
|
|
{
|
|
prep.recalculate_flag = false;
|
|
}
|
|
#else
|
|
prep.recalculate_flag = false;
|
|
#endif
|
|
}
|
|
else
|
|
{
|
|
// Load the Bresenham stepping data for the block.
|
|
prep.st_block_index = Stepper_NextBlockIndex(prep.st_block_index);
|
|
|
|
// Prepare and copy Bresenham algorithm segment data from the new planner block, so that
|
|
// when the segment buffer completes the planner block, it may be discarded when the
|
|
// segment buffer finishes the prepped block, but the stepper ISR is still executing it.
|
|
st_prep_block = &st_block_buffer[prep.st_block_index];
|
|
st_prep_block->direction_bits = pl_block->direction_bits;
|
|
|
|
uint8_t idx;
|
|
// With AMASS enabled, simply bit-shift multiply all Bresenham data by the max AMASS
|
|
// level, such that we never divide beyond the original data anywhere in the algorithm.
|
|
// If the original data is divided, we can lose a step from integer roundoff.
|
|
for(idx = 0; idx < N_AXIS; idx++)
|
|
{
|
|
st_prep_block->steps[idx] = pl_block->steps[idx] << MAX_AMASS_LEVEL;
|
|
}
|
|
|
|
st_prep_block->step_event_count = pl_block->step_event_count << MAX_AMASS_LEVEL;
|
|
|
|
// Initialize segment buffer data for generating the segments.
|
|
prep.steps_remaining = (float)pl_block->step_event_count;
|
|
prep.step_per_mm = prep.steps_remaining/pl_block->millimeters;
|
|
prep.req_mm_increment = REQ_MM_INCREMENT_SCALAR/prep.step_per_mm;
|
|
prep.dt_remainder = 0.0; // Reset for new segment block
|
|
|
|
if((sys.step_control & STEP_CONTROL_EXECUTE_HOLD) || (prep.recalculate_flag & PREP_FLAG_DECEL_OVERRIDE))
|
|
{
|
|
// New block loaded mid-hold. Override planner block entry speed to enforce deceleration.
|
|
prep.current_speed = prep.exit_speed;
|
|
pl_block->entry_speed_sqr = prep.exit_speed*prep.exit_speed;
|
|
prep.recalculate_flag &= ~(PREP_FLAG_DECEL_OVERRIDE);
|
|
}
|
|
else
|
|
{
|
|
prep.current_speed = sqrtf(pl_block->entry_speed_sqr);
|
|
}
|
|
|
|
// Setup laser mode variables. PWM rate adjusted motions will always complete a motion with the
|
|
// spindle off.
|
|
st_prep_block->is_pwm_rate_adjusted = false;
|
|
|
|
if (BIT_IS_TRUE(settings.flags, BITFLAG_LASER_MODE))
|
|
{
|
|
if(pl_block->condition & PL_COND_FLAG_SPINDLE_CCW)
|
|
{
|
|
// Pre-compute inverse programmed rate to speed up PWM updating per step segment.
|
|
prep.inv_rate = 1.0/pl_block->programmed_rate;
|
|
st_prep_block->is_pwm_rate_adjusted = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------------------
|
|
Compute the velocity profile of a new planner block based on its entry and exit
|
|
speeds, or recompute the profile of a partially-completed planner block if the
|
|
planner has updated it. For a commanded forced-deceleration, such as from a feed
|
|
hold, override the planner velocities and decelerate to the target exit speed.
|
|
*/
|
|
prep.mm_complete = 0.0; // Default velocity profile complete at 0.0mm from end of block.
|
|
float inv_2_accel = 0.5/pl_block->acceleration;
|
|
|
|
if(sys.step_control & STEP_CONTROL_EXECUTE_HOLD) // [Forced Deceleration to Zero Velocity]
|
|
{
|
|
// Compute velocity profile parameters for a feed hold in-progress. This profile overrides
|
|
// the planner block profile, enforcing a deceleration to zero speed.
|
|
prep.ramp_type = RAMP_DECEL;
|
|
// Compute decelerate distance relative to end of block.
|
|
float decel_dist = pl_block->millimeters - inv_2_accel*pl_block->entry_speed_sqr;
|
|
|
|
if(decel_dist < 0.0)
|
|
{
|
|
// Deceleration through entire planner block. End of feed hold is not in this block.
|
|
prep.exit_speed = sqrtf(pl_block->entry_speed_sqr-2*pl_block->acceleration*pl_block->millimeters);
|
|
}
|
|
else
|
|
{
|
|
prep.mm_complete = decel_dist; // End of feed hold.
|
|
prep.exit_speed = 0.0;
|
|
}
|
|
}
|
|
else // [Normal Operation]
|
|
{
|
|
// Compute or recompute velocity profile parameters of the prepped planner block.
|
|
prep.ramp_type = RAMP_ACCEL; // Initialize as acceleration ramp.
|
|
prep.accelerate_until = pl_block->millimeters;
|
|
|
|
float exit_speed_sqr;
|
|
float nominal_speed;
|
|
|
|
if(sys.step_control & STEP_CONTROL_EXECUTE_SYS_MOTION)
|
|
{
|
|
prep.exit_speed = exit_speed_sqr = 0.0; // Enforce stop at end of system motion.
|
|
}
|
|
else
|
|
{
|
|
exit_speed_sqr = Planner_GetExecBlockExitSpeedSqr();
|
|
prep.exit_speed = sqrtf(exit_speed_sqr);
|
|
}
|
|
|
|
nominal_speed = Planner_ComputeProfileNominalSpeed(pl_block);
|
|
|
|
float nominal_speed_sqr = nominal_speed*nominal_speed;
|
|
float intersect_distance = 0.5*(pl_block->millimeters+inv_2_accel*(pl_block->entry_speed_sqr-exit_speed_sqr));
|
|
|
|
if(pl_block->entry_speed_sqr > nominal_speed_sqr) // Only occurs during override reductions.
|
|
{
|
|
prep.accelerate_until = pl_block->millimeters - inv_2_accel*(pl_block->entry_speed_sqr-nominal_speed_sqr);
|
|
if(prep.accelerate_until <= 0.0) // Deceleration-only.
|
|
{
|
|
prep.ramp_type = RAMP_DECEL;
|
|
// prep.decelerate_after = pl_block->millimeters;
|
|
// prep.maximum_speed = prep.current_speed;
|
|
|
|
// Compute override block exit speed since it doesn't match the planner exit speed.
|
|
prep.exit_speed = sqrtf(pl_block->entry_speed_sqr - 2*pl_block->acceleration*pl_block->millimeters);
|
|
prep.recalculate_flag |= PREP_FLAG_DECEL_OVERRIDE; // Flag to load next block as deceleration override.
|
|
|
|
// TODO: Determine correct handling of parameters in deceleration-only.
|
|
// Can be tricky since entry speed will be current speed, as in feed holds.
|
|
// Also, look into near-zero speed handling issues with this.
|
|
}
|
|
else
|
|
{
|
|
// Decelerate to cruise or cruise-decelerate types. Guaranteed to intersect updated plan.
|
|
prep.decelerate_after = inv_2_accel*(nominal_speed_sqr-exit_speed_sqr);
|
|
prep.maximum_speed = nominal_speed;
|
|
prep.ramp_type = RAMP_DECEL_OVERRIDE;
|
|
}
|
|
}
|
|
else if(intersect_distance > 0.0)
|
|
{
|
|
if (intersect_distance < pl_block->millimeters) // Either trapezoid or triangle types
|
|
{
|
|
// NOTE: For acceleration-cruise and cruise-only types, following calculation will be 0.0.
|
|
prep.decelerate_after = inv_2_accel*(nominal_speed_sqr-exit_speed_sqr);
|
|
if(prep.decelerate_after < intersect_distance) // Trapezoid type
|
|
{
|
|
prep.maximum_speed = nominal_speed;
|
|
|
|
if(pl_block->entry_speed_sqr == nominal_speed_sqr)
|
|
{
|
|
// Cruise-deceleration or cruise-only type.
|
|
prep.ramp_type = RAMP_CRUISE;
|
|
}
|
|
else
|
|
{
|
|
// Full-trapezoid or acceleration-cruise types
|
|
prep.accelerate_until -= inv_2_accel*(nominal_speed_sqr-pl_block->entry_speed_sqr);
|
|
}
|
|
}
|
|
else // Triangle type
|
|
{
|
|
prep.accelerate_until = intersect_distance;
|
|
prep.decelerate_after = intersect_distance;
|
|
prep.maximum_speed = sqrtf(2.0*pl_block->acceleration*intersect_distance+exit_speed_sqr);
|
|
}
|
|
}
|
|
else // Deceleration-only type
|
|
{
|
|
prep.ramp_type = RAMP_DECEL;
|
|
// prep.decelerate_after = pl_block->millimeters;
|
|
// prep.maximum_speed = prep.current_speed;
|
|
}
|
|
}
|
|
else // Acceleration-only type
|
|
{
|
|
prep.accelerate_until = 0.0;
|
|
// prep.decelerate_after = 0.0;
|
|
prep.maximum_speed = prep.exit_speed;
|
|
}
|
|
}
|
|
|
|
BIT_TRUE(sys.step_control, STEP_CONTROL_UPDATE_SPINDLE_PWM); // Force update whenever updating block.
|
|
}
|
|
|
|
// Initialize new segment
|
|
Stepper_Segment_t *prep_segment = &segment_buffer[segment_buffer_head];
|
|
|
|
// Set new segment to point to the current segment data block.
|
|
prep_segment->st_block_index = prep.st_block_index;
|
|
|
|
prep_segment->backlash_motion = pl_block->backlash_motion;
|
|
|
|
/*------------------------------------------------------------------------------------
|
|
Compute the average velocity of this new segment by determining the total distance
|
|
traveled over the segment time DT_SEGMENT. The following code first attempts to create
|
|
a full segment based on the current ramp conditions. If the segment time is incomplete
|
|
when terminating at a ramp state change, the code will continue to loop through the
|
|
progressing ramp states to fill the remaining segment execution time. However, if
|
|
an incomplete segment terminates at the end of the velocity profile, the segment is
|
|
considered completed despite having a truncated execution time less than DT_SEGMENT.
|
|
The velocity profile is always assumed to progress through the ramp sequence:
|
|
acceleration ramp, cruising state, and deceleration ramp. Each ramp's travel distance
|
|
may range from zero to the length of the block. Velocity profiles can end either at
|
|
the end of planner block (typical) or mid-block at the end of a forced deceleration,
|
|
such as from a feed hold.
|
|
*/
|
|
float dt_max = DT_SEGMENT; // Maximum segment time
|
|
float dt = 0.0; // Initialize segment time
|
|
float time_var = dt_max; // Time worker variable
|
|
float mm_var; // mm-Distance worker variable
|
|
float speed_var; // Speed worker variable
|
|
float mm_remaining = pl_block->millimeters; // New segment distance from end of block.
|
|
float minimum_mm = mm_remaining-prep.req_mm_increment; // Guarantee at least one step.
|
|
|
|
if(minimum_mm < 0.0)
|
|
{
|
|
minimum_mm = 0.0;
|
|
}
|
|
|
|
do
|
|
{
|
|
switch(prep.ramp_type)
|
|
{
|
|
case RAMP_DECEL_OVERRIDE:
|
|
speed_var = pl_block->acceleration*time_var;
|
|
mm_var = time_var*(prep.current_speed - 0.5*speed_var);
|
|
mm_remaining -= mm_var;
|
|
|
|
if((mm_remaining < prep.accelerate_until) || (mm_var <= 0))
|
|
{
|
|
// Cruise or cruise-deceleration types only for deceleration override.
|
|
mm_remaining = prep.accelerate_until; // NOTE: 0.0 at EOB
|
|
time_var = 2.0*(pl_block->millimeters-mm_remaining)/(prep.current_speed+prep.maximum_speed);
|
|
prep.ramp_type = RAMP_CRUISE;
|
|
prep.current_speed = prep.maximum_speed;
|
|
}
|
|
else // Mid-deceleration override ramp.
|
|
{
|
|
prep.current_speed -= speed_var;
|
|
}
|
|
break;
|
|
|
|
case RAMP_ACCEL:
|
|
// NOTE: Acceleration ramp only computes during first do-while loop.
|
|
speed_var = pl_block->acceleration*time_var;
|
|
mm_remaining -= time_var*(prep.current_speed + 0.5*speed_var);
|
|
|
|
if(mm_remaining < prep.accelerate_until) // End of acceleration ramp.
|
|
{
|
|
// Acceleration-cruise, acceleration-deceleration ramp junction, or end of block.
|
|
mm_remaining = prep.accelerate_until; // NOTE: 0.0 at EOB
|
|
time_var = 2.0*(pl_block->millimeters-mm_remaining)/(prep.current_speed+prep.maximum_speed);
|
|
|
|
if(mm_remaining == prep.decelerate_after)
|
|
{
|
|
prep.ramp_type = RAMP_DECEL;
|
|
}
|
|
else
|
|
{
|
|
prep.ramp_type = RAMP_CRUISE;
|
|
}
|
|
prep.current_speed = prep.maximum_speed;
|
|
}
|
|
else // Acceleration only.
|
|
{
|
|
prep.current_speed += speed_var;
|
|
}
|
|
break;
|
|
|
|
case RAMP_CRUISE:
|
|
// NOTE: mm_var used to retain the last mm_remaining for incomplete segment time_var calculations.
|
|
// NOTE: If maximum_speed*time_var value is too low, round-off can cause mm_var to not change. To
|
|
// prevent this, simply enforce a minimum speed threshold in the planner.
|
|
mm_var = mm_remaining - prep.maximum_speed*time_var;
|
|
|
|
if(mm_var < prep.decelerate_after) // End of cruise.
|
|
{
|
|
// Cruise-deceleration junction or end of block.
|
|
time_var = (mm_remaining - prep.decelerate_after)/prep.maximum_speed;
|
|
mm_remaining = prep.decelerate_after; // NOTE: 0.0 at EOB
|
|
prep.ramp_type = RAMP_DECEL;
|
|
}
|
|
else // Cruising only.
|
|
{
|
|
mm_remaining = mm_var;
|
|
}
|
|
break;
|
|
|
|
default: // case RAMP_DECEL:
|
|
// NOTE: mm_var used as a misc worker variable to prevent errors when near zero speed.
|
|
speed_var = pl_block->acceleration*time_var; // Used as delta speed (mm/min)
|
|
|
|
if(prep.current_speed > speed_var) // Check if at or below zero speed.
|
|
{
|
|
// Compute distance from end of segment to end of block.
|
|
mm_var = mm_remaining - time_var*(prep.current_speed - 0.5*speed_var); // (mm)
|
|
|
|
if(mm_var > prep.mm_complete) // Typical case. In deceleration ramp.
|
|
{
|
|
mm_remaining = mm_var;
|
|
prep.current_speed -= speed_var;
|
|
break; // Segment complete. Exit switch-case statement. Continue do-while loop.
|
|
}
|
|
}
|
|
// Otherwise, at end of block or end of forced-deceleration.
|
|
time_var = 2.0*(mm_remaining-prep.mm_complete)/(prep.current_speed+prep.exit_speed);
|
|
mm_remaining = prep.mm_complete;
|
|
prep.current_speed = prep.exit_speed;
|
|
}
|
|
|
|
dt += time_var; // Add computed ramp time to total segment time.
|
|
|
|
if(dt < dt_max)
|
|
{
|
|
time_var = dt_max - dt;
|
|
} // **Incomplete** At ramp junction.
|
|
else
|
|
{
|
|
if(mm_remaining > minimum_mm) // Check for very slow segments with zero steps.
|
|
{
|
|
// Increase segment time to ensure at least one step in segment. Override and loop
|
|
// through distance calculations until minimum_mm or mm_complete.
|
|
dt_max += DT_SEGMENT;
|
|
time_var = dt_max - dt;
|
|
}
|
|
else
|
|
{
|
|
break; // **Complete** Exit loop. Segment execution time maxed.
|
|
}
|
|
}
|
|
} while(mm_remaining > prep.mm_complete); // **Complete** Exit loop. Profile complete.
|
|
|
|
/* -----------------------------------------------------------------------------------
|
|
Compute spindle speed PWM output for step segment
|
|
*/
|
|
|
|
if(st_prep_block->is_pwm_rate_adjusted || (sys.step_control & STEP_CONTROL_UPDATE_SPINDLE_PWM))
|
|
{
|
|
if(pl_block->condition & (PL_COND_FLAG_SPINDLE_CW | PL_COND_FLAG_SPINDLE_CCW))
|
|
{
|
|
float rpm = pl_block->spindle_speed;
|
|
|
|
// NOTE: Feed and rapid overrides are independent of PWM value and do not alter laser power/rate.
|
|
if(st_prep_block->is_pwm_rate_adjusted)
|
|
{
|
|
rpm *= (prep.current_speed * prep.inv_rate);
|
|
}
|
|
|
|
// If current_speed is zero, then may need to be rpm_min*(100/MAX_SPINDLE_SPEED_OVERRIDE)
|
|
// but this would be instantaneous only and during a motion. May not matter at all.
|
|
prep.current_spindle_pwm = Spindle_ComputePwmValue(rpm);
|
|
}
|
|
else
|
|
{
|
|
sys.spindle_speed = 0.0;
|
|
prep.current_spindle_pwm = SPINDLE_PWM_OFF_VALUE;
|
|
}
|
|
|
|
BIT_FALSE(sys.step_control, STEP_CONTROL_UPDATE_SPINDLE_PWM);
|
|
}
|
|
|
|
prep_segment->spindle_pwm = prep.current_spindle_pwm; // Reload segment PWM value
|
|
|
|
|
|
/* -----------------------------------------------------------------------------------
|
|
Compute segment step rate, steps to execute, and apply necessary rate corrections.
|
|
NOTE: Steps are computed by direct scalar conversion of the millimeter distance
|
|
remaining in the block, rather than incrementally tallying the steps executed per
|
|
segment. This helps in removing floating point round-off issues of several additions.
|
|
However, since floats have only 7.2 significant digits, long moves with extremely
|
|
high step counts can exceed the precision of floats, which can lead to lost steps.
|
|
Fortunately, this scenario is highly unlikely and unrealistic in CNC machines
|
|
supported by Grbl (i.e. exceeding 10 meters axis travel at 200 step/mm).
|
|
*/
|
|
float step_dist_remaining = prep.step_per_mm*mm_remaining; // Convert mm_remaining to steps
|
|
float n_steps_remaining = ceilf(step_dist_remaining); // Round-up current steps remaining
|
|
float last_n_steps_remaining = ceilf(prep.steps_remaining); // Round-up last steps remaining
|
|
prep_segment->n_step = last_n_steps_remaining-n_steps_remaining; // Compute number of steps to execute.
|
|
|
|
// Bail if we are at the end of a feed hold and don't have a step to execute.
|
|
if(prep_segment->n_step == 0)
|
|
{
|
|
if(sys.step_control & STEP_CONTROL_EXECUTE_HOLD)
|
|
{
|
|
// Less than one step to decelerate to zero speed, but already very close. AMASS
|
|
// requires full steps to execute. So, just bail.
|
|
BIT_TRUE(sys.step_control, STEP_CONTROL_END_MOTION);
|
|
#ifdef PARKING_ENABLE
|
|
if(!(prep.recalculate_flag & PREP_FLAG_PARKING))
|
|
{
|
|
prep.recalculate_flag |= PREP_FLAG_HOLD_PARTIAL_BLOCK;
|
|
}
|
|
#endif
|
|
return; // Segment not generated, but current step data still retained.
|
|
}
|
|
}
|
|
|
|
// Compute segment step rate. Since steps are integers and mm distances traveled are not,
|
|
// the end of every segment can have a partial step of varying magnitudes that are not
|
|
// executed, because the stepper ISR requires whole steps due to the AMASS algorithm. To
|
|
// compensate, we track the time to execute the previous segment's partial step and simply
|
|
// apply it with the partial step distance to the current segment, so that it minutely
|
|
// adjusts the whole segment rate to keep step output exact. These rate adjustments are
|
|
// typically very small and do not adversely effect performance, but ensures that Grbl
|
|
// outputs the exact acceleration and velocity profiles as computed by the planner.
|
|
dt += prep.dt_remainder; // Apply previous segment partial step execute time
|
|
|
|
float inv_rate = dt/(last_n_steps_remaining - step_dist_remaining); // Compute adjusted step rate inverse
|
|
|
|
// Compute CPU cycles per step for the prepped segment.
|
|
uint32_t cycles = ceilf((TICKS_PER_MICROSECOND*1000000*60)*inv_rate); // (cycles/step)
|
|
|
|
// Compute step timing and multi-axis smoothing level.
|
|
// NOTE: AMASS overdrives the timer with each level, so only one prescalar is required.
|
|
if(cycles < AMASS_LEVEL1)
|
|
{
|
|
prep_segment->amass_level = 0;
|
|
}
|
|
else
|
|
{
|
|
if(cycles < AMASS_LEVEL2)
|
|
{
|
|
prep_segment->amass_level = 1;
|
|
}
|
|
else if(cycles < AMASS_LEVEL3)
|
|
{
|
|
prep_segment->amass_level = 2;
|
|
}
|
|
else if (cycles < AMASS_LEVEL4)
|
|
{
|
|
prep_segment->amass_level = 3;
|
|
}
|
|
else if (cycles < AMASS_LEVEL5)
|
|
{
|
|
prep_segment->amass_level = 4;
|
|
}
|
|
else
|
|
{
|
|
prep_segment->amass_level = 5;
|
|
}
|
|
|
|
cycles >>= prep_segment->amass_level;
|
|
prep_segment->n_step <<= prep_segment->amass_level;
|
|
}
|
|
|
|
if(cycles < (1UL << 16))
|
|
{
|
|
// < 65536 (2.7ms @ 24MHz)
|
|
prep_segment->cycles_per_tick = cycles;
|
|
}
|
|
else
|
|
{
|
|
// Just set the slowest speed possible.
|
|
prep_segment->cycles_per_tick = 0xffff;
|
|
}
|
|
|
|
// Segment complete! Increment segment buffer indices, so stepper ISR can immediately execute it.
|
|
segment_buffer_head = segment_next_head;
|
|
if(++segment_next_head == SEGMENT_BUFFER_SIZE)
|
|
{
|
|
segment_next_head = 0;
|
|
}
|
|
|
|
// Update the appropriate planner and segment data.
|
|
pl_block->millimeters = mm_remaining;
|
|
prep.steps_remaining = n_steps_remaining;
|
|
prep.dt_remainder = (n_steps_remaining - step_dist_remaining)*inv_rate;
|
|
|
|
// Check for exit conditions and flag to load next planner block.
|
|
if(mm_remaining == prep.mm_complete)
|
|
{
|
|
// End of planner block or forced-termination. No more distance to be executed.
|
|
if(mm_remaining > 0.0) // At end of forced-termination.
|
|
{
|
|
// Reset prep parameters for resuming and then bail. Allow the stepper ISR to complete
|
|
// the segment queue, where realtime protocol will set new state upon receiving the
|
|
// cycle stop flag from the ISR. Prep_segment is blocked until then.
|
|
BIT_TRUE(sys.step_control, STEP_CONTROL_END_MOTION);
|
|
#ifdef PARKING_ENABLE
|
|
if(!(prep.recalculate_flag & PREP_FLAG_PARKING))
|
|
{
|
|
prep.recalculate_flag |= PREP_FLAG_HOLD_PARTIAL_BLOCK;
|
|
}
|
|
#endif
|
|
return; // Bail!
|
|
}
|
|
else // End of planner block
|
|
{
|
|
// The planner block is complete. All steps are set to be executed in the segment buffer.
|
|
if(sys.step_control & STEP_CONTROL_EXECUTE_SYS_MOTION)
|
|
{
|
|
BIT_TRUE(sys.step_control, STEP_CONTROL_END_MOTION);
|
|
|
|
return;
|
|
}
|
|
|
|
pl_block = 0; // Set pointer to indicate check and load next planner block.
|
|
Planner_DiscardCurrentBlock();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
// Called by realtime status reporting to fetch the current speed being executed. This value
|
|
// however is not exactly the current speed, but the speed computed in the last step segment
|
|
// in the segment buffer. It will always be behind by up to the number of segment blocks (-1)
|
|
// divided by the ACCELERATION TICKS PER SECOND in seconds.
|
|
float Stepper_GetRealtimeRate(void)
|
|
{
|
|
if(sys.state & (STATE_CYCLE | STATE_HOMING | STATE_HOLD | STATE_JOG | STATE_SAFETY_DOOR))
|
|
{
|
|
return prep.current_speed;
|
|
}
|
|
|
|
return 0.0f;
|
|
}
|