ManuelW/grbl-LPC-CoreXY
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successfully maintained 30khz, lots of optimization of code and buffering allocation

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This commit is contained in:
Simen Svale Skogsrud
2010-03-03 00:26:48 +01:00
parent 2be1f473cd
commit df243d2490
5 changed files with 56 additions and 102 deletions
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53
stepper.c
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@ -25,6 +25,7 @@
#include "stepper.h"
#include "config.h"
#include <math.h>
#include <stdlib.h>
#include <util/delay.h>
#include "nuts_bolts.h"
#include <avr/interrupt.h>
@ -32,30 +33,30 @@
#include "wiring_serial.h"
#define TICKS_PER_MICROSECOND (F_CPU/1000000)
#define LINE_BUFFER_SIZE 5
#define LINE_BUFFER_SIZE 8
struct Line {
uint32_t steps_x, steps_y, steps_z;
uint32_t maximum_steps;
uint32_t iterations;
int32_t maximum_steps;
uint8_t direction_bits;
uint32_t rate;
}
};
volatile uint8_t line_buffer[LINE_BUFFER_SIZE]; // A buffer for step instructions
struct Line line_buffer[LINE_BUFFER_SIZE]; // A buffer for step instructions
volatile int line_buffer_head = 0;
volatile int line_buffer_tail = 0;
// Variables used by SIG_OUTPUT_COMPARE1A
uint8_t out_bits;
struct Line *current_line;
uint32_t counter_x, counter_y, counter_z;
volatile int32_t counter_x, counter_y, counter_z;
uint32_t iterations;
uint8_t stepper_mode = STEPPER_MODE_STOPPED;
void config_pace_timer(uint32_t microseconds);
void st_buffer_line(int32_t steps_x, int32_t steps_y, int32_t steps_z, uint32_t rate) {
void st_buffer_line(int32_t steps_x, int32_t steps_y, int32_t steps_z, uint32_t microseconds) {
// Buffer nothing unless stepping subsystem is running
if (stepper_mode != STEPPER_MODE_RUNNING) { return; }
// Calculate the buffer head after we push this byte
@ -68,18 +69,20 @@ void st_buffer_line(int32_t steps_x, int32_t steps_y, int32_t steps_z, uint32_t
struct Line *line = &line_buffer[line_buffer_head];
line->steps_x = labs(steps_x);
line->steps_y = labs(steps_y);
line->steps_z = labs(steps_y);
line->steps_z = labs(steps_z);
line->maximum_steps = max(line->steps_x, max(line->steps_y, line->steps_z));
line->iterations = line->maximum_steps;
line->rate = rate;
// Bail if this is a zero-length line
if (line->maximum_steps == 0) { return; };
line->rate = microseconds/line->maximum_steps;
uint8_t direction_bits = 0;
if (steps_x < 0) { direction_bits |= (1<<X_DIRECTION_BIT); }
if (steps_y < 0) { direction_bits |= (1<<Y_DIRECTION_BIT); }
if (steps_z < 0) { direction_bits |= (1<<Z_DIRECTION_BIT); }
line->direction_bits = direction_bits;
// Move buffer head
line_buffer_head = next_buffer_head;
// enable stepper interrupt
TIMSK1 |= (1<<OCIE1A);
}
// This timer interrupt is executed at the pace set with st_buffer_pace. It pops one instruction from
@ -87,6 +90,7 @@ void st_buffer_line(int32_t steps_x, int32_t steps_y, int32_t steps_z, uint32_t
// five microseconds.
SIGNAL(SIG_OUTPUT_COMPARE1A)
{
PORTD |= (1<<3);
// Set the direction pins a cuple of nanoseconds before we step the steppers
STEPPING_PORT = (STEPPING_PORT & ~DIRECTION_MASK) | (out_bits & DIRECTION_MASK);
// Then pulse the stepping pins
@ -96,18 +100,23 @@ SIGNAL(SIG_OUTPUT_COMPARE1A)
// If there is no current line, attempt to pop one from the buffer
if (current_line == NULL) {
PORTD &= ~(1<<4);
// Anything in the buffer?
if (line_buffer_head != line_buffer_tail) {
PORTD ^= (1<<5);
// Retrieve a new line and get ready to step it
current_line = &line_buffer[line_buffer_tail];
config_pace_timer(current_line->rate);
counter_x = -current_line->maximum_steps/2;
counter_x = -(current_line->maximum_steps/2);
counter_y = counter_x;
counter_z = counter_x;
// move the line buffer tail to the next instruction
line_buffer_tail = (line_buffer_tail + 1) % LINE_BUFFER_SIZE;
}
}
iterations = current_line->maximum_steps;
} else {
// disable this interrupt until there is something to handle
TIMSK1 &= ~(1<<OCIE1A);
PORTD |= (1<<4);
}
}
if (current_line != NULL) {
out_bits = current_line->direction_bits;
@ -116,25 +125,28 @@ SIGNAL(SIG_OUTPUT_COMPARE1A)
out_bits |= (1<<X_STEP_BIT);
counter_x -= current_line->maximum_steps;
}
counter_y += current_line-> steps_y;
counter_y += current_line->steps_y;
if (counter_y > 0) {
out_bits |= (1<<Y_STEP_BIT);
counter_y -= current_line->maximum_steps;
}
counter_z += current_line-> steps_z;
counter_z += current_line->steps_z;
if (counter_z > 0) {
out_bits |= (1<<Z_STEP_BIT);
counter_z -= current_line->maximum_steps;
}
// If current line is finished, reset pointer
current_line->iterations -= 1;
if (current_line->iterations <= 0) {
iterations -= 1;
if (iterations <= 0) {
current_line = NULL;
// move the line buffer tail to the next instruction
line_buffer_tail = (line_buffer_tail + 1) % LINE_BUFFER_SIZE;
}
} else {
out_bits = 0;
}
out_bits ^= STEPPING_INVERT_MASK;
PORTD &= ~(1<<3);
}
// This interrupt is set up by SIG_OUTPUT_COMPARE1A when it sets the motor port bits. It resets
@ -258,7 +270,6 @@ void config_pace_timer(uint32_t microseconds)
TCCR1B = (TCCR1B & ~(0x07<<CS10)) | ((prescaler+1)<<CS10);
// Set ceiling
OCR1A = ceiling;
current_pace = microseconds;
}
int check_limit_switches()